U.S. patent application number 16/715527 was filed with the patent office on 2020-04-16 for systems and methods using lanthanide halide.
The applicant listed for this patent is Calera Corporation. Invention is credited to Thomas A Albrecht, Emily A Cole, Ryan J Gilliam, Michael Kostowskyj, Margarete K Leclerc, Kyle Self, Michael J Weiss.
Application Number | 20200115809 16/715527 |
Document ID | / |
Family ID | 70159777 |
Filed Date | 2020-04-16 |
![](/patent/app/20200115809/US20200115809A1-20200416-C00001.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00002.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00003.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00004.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00005.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00006.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00007.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00008.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00009.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00010.png)
![](/patent/app/20200115809/US20200115809A1-20200416-C00011.png)
View All Diagrams
United States Patent
Application |
20200115809 |
Kind Code |
A1 |
Leclerc; Margarete K ; et
al. |
April 16, 2020 |
SYSTEMS AND METHODS USING LANTHANIDE HALIDE
Abstract
There are provided methods and systems related to use of one or
more lanthanide halides in an electrochemical oxidation of metal
halide in anolyte where the metal ion is oxidized from lower
oxidation state to higher oxidation state at an anode; and then
further use of the one or more lanthanide halides and the metal
halide with the metal ion in the higher oxidation state in a
halogenation reaction of an unsaturated hydrocarbon or a saturated
hydrocarbon to form one or more products comprising
halohydrocarbon.
Inventors: |
Leclerc; Margarete K;
(Mountain View, CA) ; Cole; Emily A; (Monterey,
CA) ; Albrecht; Thomas A; (Santa Clara, CA) ;
Kostowskyj; Michael; (Aptos, CA) ; Gilliam; Ryan
J; (San Jose, CA) ; Weiss; Michael J; (Los
Gatos, CA) ; Self; Kyle; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Calera Corporation |
Moss Landing |
CA |
US |
|
|
Family ID: |
70159777 |
Appl. No.: |
16/715527 |
Filed: |
December 16, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16135357 |
Sep 19, 2018 |
10556848 |
|
|
16715527 |
|
|
|
|
62560363 |
Sep 19, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25B 3/06 20130101; C25B
9/08 20130101 |
International
Class: |
C25B 3/06 20060101
C25B003/06; C25B 9/08 20060101 C25B009/08 |
Claims
1. A method, comprising: contacting an anode with an anode
electrolyte wherein the anode electrolyte comprises metal halide,
one or more lanthanide halides, and water; contacting cathode with
a cathode electrolyte; applying voltage to the anode and the
cathode and oxidizing the metal halide from a lower oxidation state
to a higher oxidation state at the anode; and reacting an
unsaturated hydrocarbon or a saturated hydrocarbon with the metal
halide in the higher oxidation state and the one or more lanthanide
halides in the anode electrolyte, to result in one or more products
comprising halohydrocarbon.
2. The method of claim 1, wherein lanthanide in the lanthanide
halide is selected from the group consisting of lanthanum, cerium,
praseodymium, neodymium, promethium, samarium, europium,
gadolinium, terbium, dysprosium, holmium, erbium, thulium,
ytterbium, lutetium, and combinations thereof.
3. The method of claim 1, wherein the lanthanide halide is cerium
halide and/or lanthanum halide.
4. The method of claim 3, wherein the cerium halide is
CeCl.sub.3.7H.sub.2O.
5. The method of claim 1, wherein the one or more lanthanide
halides are in concentration range of between about 0.4-10 mol
%.
6. The method of claim 1, wherein the anode electrolyte further
comprises salt.
7. The method of claim 1, wherein the anode electrolyte comprises
the metal halide with metal ion in the higher oxidation state in
range of about 4-17 mol %; the metal halide with metal ion in the
lower oxidation state in range of about 0.5-5 mol %; sodium
chloride in range of about 0-10 mol %; and cerium chloride in range
of about 0.5-10 mol %.
8. The method of claim 1, wherein ratio of the one or more
lanthanide halides to the metal halide with metal ion in both lower
oxidation state and higher oxidation state is between about 3:1 to
1:10.
9. The method of claim 1, wherein the one or more lanthanide
halides result in more than 90% selectivity of the
halohydrocarbon.
10. The method of claim 1, wherein the one or more lanthanide
halides reduce temperature of the reaction by more than 5.degree.
C. with substantially same or higher selectivity and/or space time
yield (STY) of the halohydrocarbon as compared to when no
lanthanide halide is used.
11. The method of claim 1, wherein the metal halide in the lower
oxidation state and the metal halide in the higher oxidation state
is CuCl and CuCl.sub.2, respectively.
12. The method of claim 1, wherein the unsaturated hydrocarbon is a
C2-C10 alkene or the saturated hydrocarbon is C2-C10 alkane.
13. The method of claim 1, wherein the unsaturated hydrocarbon is
ethylene, propylene, or butylene which reacts with the anode
electrolyte comprising the metal halide in the higher oxidation
state and the one or more lanthanide halides to form one or more
products comprising ethylene dichloride, propylene dichloride or
1,4-dichlorobutane, respectively.
14. The method of claim 1, wherein the saturated hydrocarbon is
methane, ethane, propane, or butane which reacts with the anode
electrolyte comprising the metal halide in the higher oxidation
state and the one or more lanthanide halides to form one or more
products comprising dichloro methane, ethylene dichloride,
propylene dichloride or 1,4-dichlorobutane, respectively.
15. The method of claim 1, further comprising forming an alkali,
water, or hydrogen gas at the cathode.
16. The method of claim 1, wherein the cathode electrolyte
comprises water and the cathode is an oxygen depolarizing cathode
that reduces oxygen and water to hydroxide ions; the cathode
electrolyte comprises water and the cathode is a hydrogen gas
producing cathode that reduces water to hydrogen gas and hydroxide
ions; the cathode electrolyte comprises hydrochloric acid and the
cathode is a hydrogen gas producing cathode that reduces
hydrochloric acid to hydrogen gas; or the cathode electrolyte
comprises hydrochloric acid and the cathode is an oxygen
depolarizing cathode that reacts hydrochloric acid and oxygen gas
to form water.
17. The method of claim 1, wherein metal ion in the metal halide is
selected from the group consisting of iron, chromium, copper, tin,
silver, cobalt, uranium, lead, mercury, vanadium, bismuth,
titanium, ruthenium, osmium, europium, zinc, cadmium, gold, nickel,
palladium, platinum, rhodium, iridium, manganese, technetium,
rhenium, molybdenum, tungsten, niobium, tantalum, zirconium,
hafnium, and combination thereof.
18. The method of claim 1, wherein metal ion in the metal halide is
copper.
19. The method of claim 1, wherein metal ion in the metal halide is
copper that is converted from Cu.sup.+ to Cu.sup.2+, metal ion in
the metal halide is iron that is converted from Fe.sup.2+ to
Fe.sup.3+, metal ion in the metal halide is tin that is converted
from Sn.sup.2+ to Sn.sup.4+, metal ion in the metal halide is
chromium that is converted from Cr.sup.2+ to Cr.sup.3+, metal ion
in the metal halide is platinum that is converted from Pt.sup.2+ to
Pt.sup.4+, or combination thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-part of application
Ser. No. 16/135,357, filed Sep. 19, 2018, which application claims
benefit of U.S. Provisional Application No. 62/560,363, filed Sep.
19, 2017, which is incorporated herein by reference in its entirety
in the present disclosure.
BACKGROUND
[0002] In many chemical processes, caustic soda may be required to
achieve a chemical reaction, e.g., to neutralize an acid, or buffer
pH of a solution, or precipitate an insoluble hydroxide from a
solution. One method by which the caustic soda may be produced is
by an electrochemical system. In producing the caustic soda
electrochemically, such as via chlor-alkali process, a large amount
of energy, salt, and water may be used.
[0003] Polyvinyl chloride, commonly known as PVC, may be the
third-most widely-produced plastic, after polyethylene and
polypropylene. PVC is widely used in construction because it is
durable, cheap, and easily worked. PVC may be made by
polymerization of vinyl chloride monomer which in turn may be made
from ethylene dichloride. Ethylene dichloride may be made by direct
chlorination of ethylene using chlorine gas made from the
chlor-alkali process.
[0004] The production of chlorine and caustic soda by electrolysis
of aqueous solutions of sodium chloride or brine is one of the
electrochemical processes demanding high-energy consumption. The
total energy requirement is for instance about 2% in the USA and
about 1% in Japan of the gross electric power generated, to
maintain this process by the chlor-alkali industry. The high energy
consumption may be related to high carbon dioxide emission owing to
burning of fossil fuels. Therefore, reduction in the electrical
power demand needs to be addressed to curtail environment pollution
and global warming.
SUMMARY
[0005] In one aspect, there is provided a method, comprising
contacting an anode with an anode electrolyte wherein the anode
electrolyte comprises metal ion; oxidizing the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte; and reacting an
unsaturated hydrocarbon or a saturated hydrocarbon with the anode
electrolyte comprising the metal ion in the higher oxidation state,
in an aqueous medium wherein the aqueous medium comprises more than
5 wt % water.
[0006] In one aspect, there is provided a method comprising
contacting an anode with an anode electrolyte; oxidizing metal ion
from a lower oxidation state to a higher oxidation state at the
anode; contacting a cathode with a cathode electrolyte; and adding
a ligand to the anode electrolyte wherein the ligand interacts with
the metal ion.
[0007] In some embodiments of the aforementioned aspects, the
method further comprises forming an alkali, water, or hydrogen gas
at the cathode. In some embodiments of the aforementioned aspects,
the method further comprises forming an alkali at the cathode. In
some embodiments of the aforementioned aspects, the method further
comprises forming hydrogen gas at the cathode. In some embodiments
of the aforementioned aspects, the method further comprises forming
water at the cathode. In some embodiments of the aforementioned
aspects, the cathode is an oxygen depolarizing cathode that reduces
oxygen and water to hydroxide ions. In some embodiments of the
aforementioned aspects, the cathode is a hydrogen gas producing
cathode that reduces water to hydrogen gas and hydroxide ions. In
some embodiments of the aforementioned aspects, the cathode is a
hydrogen gas producing cathode that reduces hydrochloric acid to
hydrogen gas. In some embodiments of the aforementioned aspects,
the cathode is an oxygen depolarizing cathode that reacts
hydrochloric acid and oxygen gas to form water
[0008] In some embodiments of the aforementioned aspects and
embodiments, the metal ion includes, but not limited to, iron,
chromium, copper, tin, silver, cobalt, uranium, lead, mercury,
vanadium, bismuth, titanium, ruthenium, osmium, europium, zinc,
cadmium, gold, nickel, palladium, platinum, rhodium, iridium,
manganese, technetium, rhenium, molybdenum, tungsten, niobium,
tantalum, zirconium, hafnium, and combination thereof. In some
embodiments, the metal ion includes, but not limited to, iron,
chromium, copper, and tin. In some embodiments, the metal ion is
copper. In some embodiments, the lower oxidation state of the metal
ion is 1+, 2+, 3+, 4+, or 5+. In some embodiments, the higher
oxidation state of the metal ion is 2+, 3+, 4+, 5+, or 6+. In some
embodiments, the metal ion is copper that is converted from
Cu.sup.+ to Cu.sup.2+, the metal ion is iron that is converted from
Fe.sup.2+ to Fe.sup.3+, the metal ion is tin that is converted from
Sn.sup.2+ to Sn.sup.4+, the metal ion is chromium that is converted
from Cr.sup.2+ to Cr.sup.3+, the metal ion is platinum that is
converted from Pt.sup.2+ to Pt.sup.4+, or combination thereof.
[0009] In some embodiments of the aforementioned aspects and
embodiments, no gas is used or formed at the anode.
[0010] In some embodiments of the aforementioned aspects and
embodiments, the method further comprises adding a ligand to the
anode electrolyte wherein the ligand interacts with the metal
ion.
[0011] In some embodiments of the aforementioned aspects and
embodiments, the method further comprises reacting an unsaturated
hydrocarbon or a saturated hydrocarbon with the anode electrolyte
comprising the metal ion in the higher oxidation state and the
ligand, wherein the reaction is in an aqueous medium.
[0012] In some embodiments of the aforementioned aspects and
embodiments, the reaction of the unsaturated hydrocarbon or the
saturated hydrocarbon with the anode electrolyte comprising the
metal ion in the higher oxidation state is halogenation or
sulfonation using the metal halide or the metal sulfate in the
higher oxidation state resulting in a halohydrocarbon or a
sulfohydrocarbon, respectively, and the metal halide or the metal
sulfate in the lower oxidation state. In some embodiments, the
metal halide or the metal sulfate in the lower oxidation state is
re-circulated back to the anode electrolyte.
[0013] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprising the metal ion in the
higher oxidation state further comprises the metal ion in the lower
oxidation state.
[0014] In some embodiments of the aforementioned aspects and
embodiments, the unsaturated hydrocarbon is compound of formula I
resulting in compound of formula II after halogenation or
sulfonation:
##STR00001##
[0015] wherein, n is 2-10; m is 0-5; and q is 1-5;
[0016] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0017] X is a halogen selected from chloro, bromo, and iodo;
--SO.sub.3H; or --OSO.sub.2OH.
[0018] In some embodiments, m is 0; n is 2; q is 2; and X is
chloro. In some embodiments, the compound of formula I is ethylene,
propylene, or butylene and the compound of formula II is ethylene
dichloride, propylene dichloride or 1,4-dichlorobutane,
respectively. In some embodiments, the method further comprises
forming vinyl chloride monomer from the ethylene dichloride and
forming poly(vinyl chloride) from the vinyl chloride monomer.
[0019] In some embodiments of the aforementioned aspects and
embodiments, the saturated hydrocarbon is compound of formula III
resulting in compound of formula IV after halogenation or
sulfonation:
##STR00002##
[0020] wherein, n is 2-10; k is 0-5; and s is 1-5;
[0021] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0022] X is a halogen selected from chloro, bromo, and iodo;
--SO.sub.3H; or --OSO.sub.2OH.
[0023] In some embodiments, the compound of formula III is methane,
ethane, or propane.
[0024] In some embodiments of the aforementioned aspects and
embodiments, the aqueous medium comprises between 5-90 wt %
water.
[0025] In some embodiments of the aforementioned aspects and
embodiments, the ligand results in one or more of the properties
including, but not limited to, enhanced reactivity of the metal ion
towards the unsaturated hydrocarbon, saturated hydrocarbon, or
hydrogen gas, enhanced selectivity of the metal ion towards
halogenations of the unsaturated or saturated hydrocarbon, enhanced
transfer of the halogen from the metal ion to the unsaturated
hydrocarbon, saturated hydrocarbon, or the hydrogen gas, reduced
redox potential of the electrochemical cell, enhanced solubility of
the metal ion in the aqueous medium, reduced membrane cross-over of
the metal ion to the cathode electrolyte in the electrochemical
cell, reduced corrosion of the electrochemical cell and/or the
reactor, enhanced separation of the metal ion from the acid
solution after reaction with hydrogen gas, enhanced separation of
the metal ion from the halogenated hydrocarbon solution, and
combination thereof.
[0026] In some embodiments of the aforementioned aspects and
embodiments, the ligand includes, but not limited to, substituted
or unsubstituted phosphine, substituted or unsubstituted crown
ether, substituted or unsubstituted aliphatic nitrogen, substituted
or unsubstituted pyridine, substituted or unsubstituted dinitrile,
and combination thereof.
[0027] In some embodiments of the aforementioned aspects and
embodiments, the ligand is of formula A:
##STR00003##
[0028] wherein n and m independently are 0-2 and R and R.sup.1
independently are H, alkyl, or substituted alkyl.
[0029] In some embodiments, the substituted alkyl is alkyl
substituted with one or more of a group selected from alkenyl,
halogen, amine, and substituted amine.
[0030] In some embodiments of the aforementioned aspects and
embodiments, the ligand is of formula C:
##STR00004##
[0031] wherein R is independently O, S, P, or N; and n is 0 or
1.
[0032] In some embodiments of the aforementioned aspects and
embodiments, the ligand is of formula D, or an oxide thereof:
##STR00005##
[0033] wherein R.sup.1, R.sup.2, and R.sup.3 independently are H,
alkyl, substituted alkyl, alkoxy, substituted alkoxy, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, amine,
substituted amine, cycloalkyl, substituted cycloalkyl,
heterocycloalkyl, and substituted heterocycloalkyl.
[0034] In some embodiments of the aforementioned aspects and
embodiments, the ligand is of formula E:
##STR00006##
wherein R.sup.1 and R.sup.2 independently are H, alkyl, substituted
alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl,
amine, substituted amine, cycloalkyl, substituted cycloalkyl,
heterocycloalkyl, and substituted heterocycloalkyl.
[0035] In some embodiments of the aforementioned aspects and
embodiments, the ligand is of formula F:
##STR00007##
[0036] wherein R is hydrogen, alkyl, or substituted alkyl; n is
0-2; m is 0-3; and k is 1-3.
[0037] In one aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte comprising metal ion
wherein the anode is configured to oxidize the metal ion from a
lower oxidation state to a higher oxidation state; a cathode in
contact with a cathode electrolyte; and a reactor operably
connected to the anode chamber and configured to react the anode
electrolyte comprising the metal ion in the higher oxidation state
with an unsaturated hydrocarbon or saturated hydrocarbon in an
aqueous medium wherein the aqueous medium comprises more than 5 wt
% water.
[0038] In one aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte comprising metal ion
wherein the anode is configured to oxidize the metal ion from a
lower oxidation state to a higher oxidation state; a ligand in the
anode electrolyte wherein the ligand is configured to interact with
the metal ion; and a cathode in contact with a cathode
electrolyte.
[0039] In some embodiments of the aforementioned aspects and
embodiments, the system further comprises a ligand in the anode
electrolyte wherein the ligand is configured to interact with the
metal ion.
[0040] In some embodiments of the aforementioned system aspects and
embodiments, the cathode is a gas-diffusion cathode configured to
react oxygen gas and water to form hydroxide ions. In some
embodiments of the aforementioned system aspects and embodiments,
the cathode is a hydrogen gas producing cathode configured to form
hydrogen gas and hydroxide ions by reducing water. In some
embodiments of the aforementioned system aspects and embodiments,
the cathode is a hydrogen gas producing cathode configured to
reduce an acid, such as, hydrochloric acid to hydrogen gas. In some
embodiments of the aforementioned system aspects and embodiments,
the cathode is a gas-diffusion cathode configured to react
hydrochloric acid and oxygen to form water.
[0041] In some embodiments of the aforementioned system aspects and
embodiments, the anode is configured to not form a gas.
[0042] In some embodiments of the aforementioned aspects and
embodiments, the system further comprises a precipitator configured
to contact the cathode electrolyte with divalent cations to form a
carbonate and/or bicarbonate product.
[0043] In some embodiments of the aforementioned aspects and
embodiments, the system further comprises a reactor operably
connected to the anode chamber and configured to react the anode
electrolyte comprising the metal ion in the higher oxidation state
and the ligand with an unsaturated hydrocarbon or saturated
hydrocarbon in an aqueous medium.
[0044] In some embodiments of the aforementioned aspects and
embodiments, the metal ion is copper. In some embodiments of the
aforementioned aspects and embodiments, the unsaturated hydrocarbon
is ethylene.
[0045] In another aspect, there is provided a method comprising
contacting an anode with an anode electrolyte; oxidizing a metal
ion from the lower oxidation state to a higher oxidation state at
the anode; and contacting a cathode with a cathode electrolyte
wherein the cathode is an oxygen depolarizing cathode that reduces
oxygen and water to hydroxide ions.
[0046] In another aspect, there is provided a method comprising
contacting an anode with an anode electrolyte and oxidizing a metal
ion from the lower oxidation state to a higher oxidation state at
the anode; contacting a cathode with a cathode electrolyte and
producing hydroxide ions in the cathode electrolyte; and contacting
the cathode electrolyte with a carbon dioxide gas or a solution
containing bicarbonate/carbonate ions.
[0047] In another aspect, there is provided a method comprising
contacting an anode with an anode electrolyte and oxidizing a metal
ion from the lower oxidation state to a higher oxidation state at
the anode; contacting a cathode with a cathode electrolyte; and
preventing migration of the metal ions from the anode electrolyte
to the cathode electrolyte by using a size exclusion membrane or an
anion exchange membrane.
[0048] In another aspect, there is provided a method comprising
contacting an anode with an anode electrolyte and oxidizing a metal
ion from lower oxidation state to a higher oxidation state at the
anode; and contacting a cathode with a cathode electrolyte and
producing hydroxide ions and/or hydrogen gas at the cathode; and
producing an acid by reacting the metal ion in the higher oxidation
state with hydrogen gas.
[0049] In another aspect, there is provided a method comprising
applying a voltage of less than 2.5 volts; contacting an anode with
an anode electrolyte and oxidizing a metal ion from the lower
oxidation state to a higher oxidation state at the anode; and
contacting a cathode with a cathode electrolyte wherein the cathode
produces hydroxide ions, hydrogen gas, or water.
[0050] In another aspect, there is provided a method to make green
halogenated hydrocarbon, comprising contacting an anode with an
anode electrolyte and oxidizing a metal chloride from the lower
oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte; and halogenating
an unsaturated hydrocarbon with the metal chloride in the higher
oxidation state to produce a green halogenated hydrocarbon.
[0051] In one aspect, there is provided a method comprising
contacting an anode with an anode electrolyte and oxidizing a metal
chloride from the lower oxidation state to a higher oxidation state
at the anode; contacting a cathode with a cathode electrolyte;
halogenating an unsaturated hydrocarbon with the metal chloride in
the higher oxidation state; and adding a ligand to the metal
chloride wherein the ligand interacts with the metal ion.
[0052] Some embodiments of the above described aspects are provided
herein. In some embodiments, the cathode is a gas-diffusion
cathode. In some embodiments, the cathode forms hydrogen gas by
reducing water or hydrochloric acid. In some embodiments, the metal
ion is selected from the group consisting of iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof. In some embodiments,
the metal ion is selected from the group consisting of iron,
chromium, copper, and tin. In some embodiments, the metal ion is
copper. In some embodiments, the metal ion is tin. In some
embodiments, the metal ion is chromium. In some embodiments, the
metal ion is iron. In some embodiments, the lower oxidation state
of the metal ion is 1+, 2+, 3+, 4+, or 5+. In some embodiments,
wherein the higher oxidation state of the metal ion is 2+, 3+, 4+,
5+, or 6+. In some embodiments, the metal ion is copper that is
converted from Cu.sup.+ to Cu.sup.2+ in the anode chamber. In some
embodiments, the metal ion is iron that is converted from Fe.sup.2+
to Fe.sup.3+ in the anode chamber. In some embodiments, the metal
ion is tin that is converted from Sn.sup.2+ to Sn.sup.4+ in the
anode chamber. In some embodiments, the metal ion is chromium that
is converted from Cr.sup.3+ to Cr.sup.6+ in the anode chamber. In
some embodiments, the metal ion is chromium that is converted from
Cr.sup.2+ to Cr.sup.3+ in the anode chamber. In some embodiments,
no gas is used or formed at the anode. In some embodiments, no acid
is formed in the anode chamber. In some embodiments, the metal ion
is in a form of metal halide. In some embodiments, the metal halide
with the metal ion in the higher oxidation state optionally
comprising the metal halide with the metal ion in the lower
oxidation state is contacted with hydrogen gas to form hydrogen
halide, such as, but not limited to, hydrogen chloride,
hydrochloric acid, hydrogen bromide, hydrobromic acid, hydrogen
iodide, or hydroiodic acid, and the metal halide with the metal ion
in the lower oxidation state. In some embodiments, the metal halide
with the metal ion in the lower oxidation state is re-circulated
back to the anode chamber. In some embodiments, the metal halide
with metal ion in higher oxidation state optionally comprising the
metal halide with the metal ion in the lower oxidation state is
contacted with an unsaturated hydrocarbon and/or saturated
hydrocarbon to form halohydrocarbon and the metal halide with the
metal ion in the lower oxidation state. In some embodiments, the
metal halide with the metal ion in the lower oxidation state is
re-circulated back to the anode chamber.
[0053] In some embodiments, the metal chloride with the metal ion
in the higher oxidation state optionally comprising the metal
chloride with the metal ion in the lower oxidation state is
contacted with hydrogen gas to form hydrochloric acid and the metal
chloride with the metal ion in the lower oxidation state. In some
embodiments, the metal chloride with the metal ion in the lower
oxidation state is re-circulated back to the anode chamber. In some
embodiments, the metal chloride with metal ion in higher oxidation
state optionally comprising the metal chloride with the metal ion
in the lower oxidation state is contacted with an unsaturated
hydrocarbon to form chlorohydrocarbon and the metal chloride with
the metal ion in the lower oxidation state. In some embodiments,
the metal chloride with the metal ion in the lower oxidation state
is re-circulated back to the anode chamber. In some embodiments,
the unsaturated hydrocarbon is ethylene and the halohydrocarbon
such as chlorohydrocarbon is ethylene dichloride. In some
embodiments, the methods described herein further include forming
vinyl chloride monomer from the ethylene dichloride. In some
embodiments, the methods described herein further include forming
poly(vinyl chloride) from the vinyl chloride monomer.
[0054] In some embodiments, the method further includes contacting
the cathode electrolyte with carbon from a source of carbon. In
some embodiments, the method further includes contacting the
cathode electrolyte with carbon selected from gaseous carbon
dioxide from an industrial process or a solution of carbon dioxide
from a gas/liquid contactor in contact with the gaseous carbon
dioxide from the industrial process. In some embodiments, the
method further includes contacting the cathode electrolyte with
divalent cations after contacting with the carbon to form carbonate
and/or bicarbonate product. In some embodiments, the method
includes applying a voltage of between 0.01 to 2.5V between the
anode and the cathode.
[0055] In some embodiments, the treatment of the metal ion in the
higher oxidation state with the unsaturated hydrocarbon is inside
the anode chamber. In some embodiments, the treatment of the metal
ion in the higher oxidation state with the unsaturated hydrocarbon
is outside the anode chamber. In some embodiments, the treatment of
the metal ion in the higher oxidation state with the unsaturated
hydrocarbon results in a chlorohydrocarbon. In some embodiments,
the chlorohydrocarbon is ethylene dichloride. In some embodiments,
the method further includes treating the Cu.sup.2+ ions with
ethylene to form ethylene dichloride. In some embodiments, the
method further includes treating the ethylene dichloride to form
vinyl chloride monomer. In some embodiments, the method further
includes treating the vinyl chloride monomer to form poly (vinyl)
chloride.
[0056] In another aspect, there is provided a system, comprising an
anode chamber comprising an anode in contact with a metal ion in an
anode electrolyte, wherein the anode chamber is configured to
convert the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising an oxygen
depolarizing cathode in contact with a cathode electrolyte, wherein
the cathode chamber is configured to produce an alkali.
[0057] In another aspect, there is provided a system, comprising an
anode chamber comprising an anode in contact with a metal ion in an
anode electrolyte wherein the anode chamber is configured to
convert the metal ion from a lower oxidation state to a higher
oxidation state; a cathode chamber comprising a cathode in contact
with a cathode electrolyte, wherein the cathode chamber is
configured to produce an alkali; and a contactor operably connected
to the cathode chamber and configured to contact carbon from a
source of carbon with the cathode electrolyte.
[0058] In another aspect, there is provided a system, comprising an
anode chamber comprising an anode in contact with a metal ion in an
anode electrolyte wherein the anode chamber is configured to
convert the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising a cathode in
contact with a cathode electrolyte, wherein the cathode chamber is
configured to produce an alkali; and a size exclusion membrane
and/or an anion exchange membrane configured to prevent migration
of the metal ion from the anode electrolyte to the cathode
electrolyte.
[0059] In another aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte wherein the anode is
configured to oxidize a metal ion from the lower oxidation state to
a higher oxidation state; a cathode in contact with a cathode
electrolyte; and a reactor operably connected to the anode chamber
and configured to react the metal ion in the higher oxidation state
with hydrogen gas to form an acid.
[0060] In another aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte wherein the anode is
configured to oxidize a metal ion from the lower oxidation state to
a higher oxidation state; a cathode in contact with a cathode
electrolyte; and a reactor operably connected to the anode chamber
and configured to react the metal ion in the higher oxidation state
with an unsaturated hydrocarbon to form a green halogenated
hydrocarbon.
[0061] In another aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte wherein the anode is
configured to oxidize a metal ion from the lower oxidation state to
a higher oxidation state; a cathode in contact with a cathode
electrolyte; a ligand in the anode electrolyte wherein the ligand
is configured to interact with the metal ion; and a reactor
operably connected to the anode chamber and configured to react the
metal ion in the higher oxidation state with an unsaturated
hydrocarbon in the presence of the ligand.
[0062] Some embodiments of the above described system aspects are
provided herein. In some embodiments, the cathode is a
gas-diffusion cathode. In some embodiments, the cathode is
configured to form hydrogen gas by reducing water. In some
embodiments, the system further includes an oxygen gas delivery
system operably connected to the cathode chamber and configured to
provide oxygen gas from a source of oxygen gas to the cathode
chamber. In some embodiments, the metal ion is in a form of metal
chloride. In some embodiments, the system further includes a
reactor operably connected to the anode chamber and configured to
contact the metal chloride with metal ion in the higher oxidation
state with an unsaturated hydrocarbon to form chlorohydrocarbon. In
some embodiments, the system further includes a contactor operably
connected to the cathode chamber and configured to contact carbon
from a source of carbon with the cathode electrolyte. In some
embodiments, the system further includes a contactor operably
connected to the cathode chamber and configured to contact carbon
from a source of carbon with the cathode electrolyte wherein the
carbon from the source of carbon is selected from gaseous carbon
dioxide from an industrial process or a solution of carbon dioxide
from a gas/liquid contactor in contact with the gaseous carbon
dioxide from the industrial process. In some embodiments, the
system further includes a precipitator to contact the cathode
electrolyte with alkaline earth metal ions to form a carbonate
and/or bicarbonate product. In one aspect, there is provided a
system including an anode chamber wherein the anode chamber
comprises an anode in contact with a metal ion in an anode
electrolyte wherein the anode chamber is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state
and an unsaturated hydrocarbon delivery system configured to
deliver the unsaturated hydrocarbon to the anode chamber. In some
embodiments, the unsaturated hydrocarbon is ethylene. In some
embodiments, the metal ion is copper ion.
[0063] In one aspect, there are provided methods, comprising
contacting an anode with an anode electrolyte wherein the anode
electrolyte comprises metal halide, one or more lanthanide halides,
and water; contacting cathode with a cathode electrolyte; applying
voltage to the anode and the cathode and oxidizing the metal halide
from a lower oxidation state to a higher oxidation state at the
anode; and reacting an unsaturated hydrocarbon or a saturated
hydrocarbon with the metal halide in the higher oxidation state and
the one or more lanthanide halides in the anode electrolyte, to
result in one or more products comprising halohydrocarbon. In some
embodiments of the above noted aspect, the lanthanide in the
lanthanide halide is selected from the group consisting of
lanthanum, cerium, praseodymium, neodymium, promethium, samarium,
europium, gadolinium, terbium, dysprosium, holmium, erbium,
thulium, ytterbium, lutetium, and combinations thereof. In some
embodiments of the above noted aspect and embodiments, the
lanthanide halide is cerium halide and/or lanthanum halide. In some
embodiments of the above noted aspect and embodiments, the cerium
halide is CeCl.sub.3.7H.sub.2O. In some embodiments of the above
noted aspect and embodiments, the one or more lanthanide halides
are in concentration range of between about 0.4-10 mol %.
[0064] In some embodiments of the above noted aspect and
embodiments, the anode electrolyte comprises the metal halide with
metal ion in the higher oxidation state in range of about 4-17 mol
%; the metal halide with metal ion in the lower oxidation state in
range of about 0.5-5 mol %; sodium chloride in range of about 0-10
mol %; and cerium chloride in range of about 0.5-10 mol %. In some
embodiments of the above noted aspect and embodiments, ratio of the
one or more lanthanide halides to the metal halide with metal ion
in both lower oxidation state and higher oxidation state is between
about 3:1 to 1:10. In some embodiments of the above noted aspect
and embodiments, the one or more lanthanide halides result in more
than 90% selectivity of the halohydrocarbon. In some embodiments of
the above noted aspect and embodiments, the one or more lanthanide
halides reduce temperature of the reaction by more than 5.degree.
C. with substantially same or higher selectivity and/or space time
yield (STY) of the halohydrocarbon as compared to when no
lanthanide halide is used.
[0065] In some embodiments, the anode electrolyte further comprises
salt. In some embodiments, the metal halide in the lower oxidation
state and the metal halide in the higher oxidation state is CuCl
and CuCl.sub.2, respectively. In some embodiments, the unsaturated
hydrocarbon is a C2-C10 alkene or the saturated hydrocarbon is
C2-C10 alkane. In some embodiments, the unsaturated hydrocarbon is
ethylene, propylene, or butylene which reacts with the anode
electrolyte comprising the metal halide in the higher oxidation
state and the one or more lanthanide halides to form one or more
products comprising ethylene dichloride, propylene dichloride or
1,4-dichlorobutane, respectively. In some embodiments, the
saturated hydrocarbon is methane, ethane, propane, or butane which
reacts with the anode electrolyte comprising the metal halide in
the higher oxidation state and the one or more lanthanide halides
to form one or more products comprising dichloro methane, ethylene
dichloride, propylene dichloride or 1,4-dichlorobutane,
respectively.
[0066] In some embodiments of the above noted aspect and
embodiments, the method further comprises forming an alkali, water,
or hydrogen gas at the cathode. In some embodiments, the cathode
electrolyte comprises water and the cathode is an oxygen
depolarizing cathode that reduces oxygen and water to hydroxide
ions; the cathode electrolyte comprises water and the cathode is a
hydrogen gas producing cathode that reduces water to hydrogen gas
and hydroxide ions; the cathode electrolyte comprises hydrochloric
acid and the cathode is a hydrogen gas producing cathode that
reduces hydrochloric acid to hydrogen gas; or the cathode
electrolyte comprises hydrochloric acid and the cathode is an
oxygen depolarizing cathode that reacts hydrochloric acid and
oxygen gas to form water. In some embodiments, the metal ion in the
metal halide is selected from the group consisting of iron,
chromium, copper, tin, silver, cobalt, uranium, lead, mercury,
vanadium, bismuth, titanium, ruthenium, osmium, europium, zinc,
cadmium, gold, nickel, palladium, platinum, rhodium, iridium,
manganese, technetium, rhenium, molybdenum, tungsten, niobium,
tantalum, zirconium, hafnium, and combination thereof. In some
embodiments, metal ion in the metal halide is copper. In some
embodiments, metal ion in the metal halide is copper that is
converted from Cu.sup.+ to Cu.sup.2+, metal ion in the metal halide
is iron that is converted from Fe.sup.2+ to Fe.sup.3+, metal ion in
the metal halide is tin that is converted from Sn.sup.2+ to
Sn.sup.4+, metal ion in the metal halide is chromium that is
converted from Cr.sup.2+ to Cr.sup.3+, metal ion in the metal
halide is platinum that is converted from Pt.sup.2+ to Pt.sup.4+,
or combination thereof.
[0067] In some embodiments, there are provided methods, comprising
contacting an anode with an anode electrolyte wherein the anode
electrolyte comprises copper (I) chloride, copper (II) chloride,
sodium chloride, cerium (III) chloride, and water; contacting
cathode with a cathode electrolyte; applying voltage to the anode
and the cathode and oxidizing the copper (I) chloride to copper
(II) chloride at the anode; and reacting an unsaturated hydrocarbon
or a saturated hydrocarbon with the copper (II) chloride and the
cerium (III) chloride in the anode electrolyte, to result in one or
more products comprising halohydrocarbon.
[0068] In one aspect, there are provided methods, comprising:
(a) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
halide in lower oxidation state and higher oxidation state; (b)
contacting a cathode with a cathode electrolyte in the
electrochemical cell; (c) applying voltage at the anode and the
cathode to conduct an oxidation reaction at the anode comprising
oxidizing metal ions of the metal halide from the lower oxidation
state to the higher oxidation state; (d) withdrawing the anode
electrolyte comprising the metal halide and reacting propylene or
propane with the anode electrolyte comprising the metal halide with
the metal ions in the higher oxidation state to form product
comprising halopropane and the metal halide with the metal ions in
the lower oxidation state; and (e) further forming propylene oxide
from the halopropane by dehydrohalogenation.
[0069] In some embodiments of the above noted aspect, the anode
electrolyte further comprises alkali metal halide. In some
embodiments of the above noted aspect and embodiments, the anode
electrolyte comprises the metal halide in the higher oxidation
state in range of 4-7M and the metal halide in the lower oxidation
state in range of 0.1-2M. In some embodiments of the above noted
aspect and embodiments, the anode electrolyte comprises more than 5
wt % water. In some embodiments of the above noted aspect and
embodiments, the alkali metal halide is in an amount between
0.01-5M in the anode electrolyte. In some embodiments of the above
noted aspect and embodiments, the alkali metal halide is alkali
metal chloride or alkali metal bromide. In some embodiments of the
above noted aspect and embodiments, the alkali metal chloride is
sodium chloride in range of 1-3M. In some embodiments of the above
noted aspect and embodiments, the alkali metal chloride is sodium
bromide.
[0070] In some embodiments of the above noted aspect and
embodiments, the cathode is an oxygen depolarizing cathode that
reduces oxygen and water to hydroxide ions; the cathode is a
hydrogen gas producing cathode that reduces water to hydrogen gas
and hydroxide ions; the cathode is a hydrogen gas producing cathode
that reduces hydrochloric acid to hydrogen gas; or the cathode is
an oxygen depolarizing cathode that reacts hydrochloric acid and
oxygen gas to form water. In some embodiments of the above noted
aspect and embodiments, the cathode is oxygen depolarized cathode
(ODC).
[0071] In some embodiments of the above noted aspect and
embodiments, the metal ions of the metal halide are selected from
the group consisting of iron, chromium, copper, tin, silver,
cobalt, uranium, lead, mercury, vanadium, bismuth, titanium,
ruthenium, osmium, europium, zinc, cadmium, gold, nickel,
palladium, platinum, rhodium, iridium, manganese, technetium,
rhenium, molybdenum, tungsten, niobium, tantalum, zirconium, and
hafnium. In some embodiments of the above noted aspect and
embodiments, the metal ions of the metal halide are selected from
the group consisting of iron, chromium, copper, and tin. In some
embodiments of the above noted aspect and embodiments, the metal
ions of the metal halide are copper.
[0072] In some embodiments of the above noted aspect and
embodiments, the metal ions of the metal halide are selected from
the group consisting of copper that is converted from Cu+ to Cu2+,
iron that is converted from Fe2+ to Fe3+, tin that is converted
from Sn2+ to Sn4+, chromium that is converted from Cr2+ to Cr3+,
and platinum that is converted from Pt2+ to Pt4+.
[0073] In one aspect, there are provided methods, comprising:
(a) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises sodium
chloride and copper chloride in lower oxidation state and higher
oxidation state; (b) contacting a cathode with a cathode
electrolyte in the electrochemical cell; (c) applying voltage at
the anode and the cathode to conduct an oxidation reaction at the
anode comprising oxidizing copper ions of the copper chloride from
the lower oxidation state to the higher oxidation state; (d)
withdrawing the anode electrolyte and reacting propylene or propane
with the anode electrolyte comprising sodium chloride and copper
chloride with the copper ions in the higher oxidation state to form
product comprising dichloropropane and propylene chlorohydrin and
the copper chloride with the copper ions in the lower oxidation
state; and (e) further forming propylene oxide from the
dichloropropane and propylene chlorohydrin.
[0074] In one aspect, there are provided methods, comprising:
(a) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises sodium
bromide and copper bromide in lower oxidation state and higher
oxidation state; (b) contacting a cathode with a cathode
electrolyte in the electrochemical cell; (c) applying voltage at
the anode and the cathode to conduct an oxidation reaction at the
anode comprising oxidizing copper ions of the copper bromide from
the lower oxidation state to the higher oxidation state; (d)
withdrawing the anode electrolyte and reacting propylene or propane
with the anode electrolyte comprising sodium bromide and copper
bromide with the copper ions in the higher oxidation state to form
product comprising dibromopropane and propylene bromohydrin and the
copper bromide with the copper ions in the lower oxidation state;
and (e) further forming propylene oxide from the dibromopropane and
propylene bromohydrin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention may be obtained by
reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0076] FIG. 1A is an illustration of an embodiment of the
invention.
[0077] FIG. 1B is an illustration of an embodiment of the
invention.
[0078] FIG. 2 is an illustration of an embodiment of the
invention.
[0079] FIG. 3A is an illustration of an embodiment of the
invention.
[0080] FIG. 3B is an illustration of an embodiment of the
invention.
[0081] FIG. 4A is an illustration of an embodiment of the
invention.
[0082] FIG. 4B is an illustration of an embodiment of the
invention.
[0083] FIG. 5A is an illustration of an embodiment of the
invention.
[0084] FIG. 5B is an illustration of an embodiment of the
invention.
[0085] FIG. 5C is an illustration of an embodiment of the
invention.
[0086] FIG. 6 is an illustration of an embodiment of the
invention.
[0087] FIG. 7A is an illustration of an embodiment of the
invention.
[0088] FIG. 7B is an illustration of an embodiment of the
invention.
[0089] FIG. 7C is an illustration of an embodiment of the
invention.
[0090] FIG. 8A is an illustration of an embodiment of the
invention.
[0091] FIG. 8B is an illustration of an embodiment of the
invention.
[0092] FIG. 8C is an illustration of an embodiment of the
invention.
[0093] FIG. 9 is an illustration of an embodiment of the
invention.
[0094] FIG. 10A is an illustration of an embodiment of the
invention.
[0095] FIG. 10B is an illustration of an embodiment of the
invention.
[0096] FIG. 11 is an illustration of an embodiment of the
invention.
[0097] FIG. 12 is an illustration of an embodiment of the
invention.
[0098] FIG. 13 is an illustration of an embodiment of the
invention.
[0099] FIG. 14 is an experimental setup as described in Example 1
herein.
[0100] FIG. 15 is an illustrative graph as described in Example 2
herein.
[0101] FIG. 16 is an illustrative graph as described in Example 3
herein.
[0102] FIG. 17A is an illustrative graph for chromium reduction
with hydrogen gas described in Example 4 herein.
[0103] FIG. 17B is an illustrative graph for copper reduction with
hydrogen gas described in Example 4 herein.
[0104] FIG. 18 is an illustrative graph as described in Example 5
herein.
[0105] FIG. 19 is an illustrative graph as described in Example 5
herein.
[0106] FIG. 20 is an illustrative embodiment as described in
Example 6 herein.
[0107] FIG. 21 is an illustrative graph as described in Example 7
herein.
[0108] FIG. 22 is an illustrative graph as described in Example 8
herein.
[0109] FIG. 23 illustrates a summary of direct current resistance
measurements of anion exchange membranes, as described in Example
9.
[0110] FIG. 24 illustrates rejection of copper ion crossover from
anion exchange membranes, as described in Example 9.
[0111] FIG. 25A illustrates few examples of the ligands used in the
reaction described in Example 10.
[0112] FIG. 25B illustrates few examples of the ligands that can be
used in the reaction described in Example 10.
[0113] FIG. 26 is an illustrative graph as described in Example 11
herein.
[0114] FIG. 27 is an illustrative graph as described in Example 12
herein.
[0115] FIG. 28 is an illustrative graph as described in Example 13
herein.
[0116] FIG. 29 is an illustrative graph as described in Example 14
herein.
[0117] FIG. 30 is an illustration of some embodiments related to
the methods and systems provided herein to form the PCH or PBH and
the PO.
[0118] FIG. 31 is an illustration of some embodiments related to
the methods and systems provided herein to form the PCH or PBH and
the PO.
[0119] FIG. 32 is an illustration of some embodiments related to
the formation of products from halogenation of propylene.
[0120] FIG. 33 is an illustration of some embodiments related to
the methods and systems provided herein to form the PCH or the PBH
and the PO.
[0121] FIG. 34 is an illustration of some embodiments related to
the methods and systems provided herein to form the PCH or the PBH
and the PO.
[0122] FIG. 35 is an illustration of some embodiments related to
the methods and systems provided herein to form the PCH or the PBH
and the PO.
DETAILED DESCRIPTION
[0123] Disclosed herein are systems and methods that relate to the
oxidation of a metal ion by the anode in the anode chamber where
the metal ion is oxidized from the lower oxidation state to a
higher oxidation state.
[0124] As can be appreciated by one ordinarily skilled in the art,
the present electrochemical system and method can be configured
with an alternative, equivalent salt solution, e.g., a potassium
chloride solution or sodium chloride solution or a magnesium
chloride solution or sodium sulfate solution or ammonium chloride
solution, to produce an equivalent alkaline solution, e.g.,
potassium hydroxide and/or potassium carbonate and/or potassium
bicarbonate or sodium hydroxide and/or sodium carbonate and/or
sodium bicarbonate or magnesium hydroxide and/or magnesium
carbonate in the cathode electrolyte. Accordingly, to the extent
that such equivalents are based on or suggested by the present
system and method, these equivalents are within the scope of the
application.
[0125] Before the present invention is described in greater detail,
it is to be understood that this invention is not limited to
particular embodiments described, as such may, of course, vary. It
is also to be understood that the terminology used herein is for
the purpose of describing particular embodiments only, and is not
intended to be limiting, since the scope of the present invention
will be limited only by the appended claims.
[0126] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
unless the context clearly dictates otherwise, between the upper
and lower limit of that range and any other stated or intervening
value in that stated range, is encompassed within the invention.
The upper and lower limits of these smaller ranges may
independently be included in the smaller ranges and are also
encompassed within the invention, subject to any specifically
excluded limit in the stated range. Where the stated range includes
one or both of the limits, ranges excluding either or both of those
included limits are also included in the invention.
[0127] Certain ranges that are presented herein with numerical
values may be construed as "about" numericals. The "about" is to
provide literal support for the exact number that it precedes, as
well as a number that is near to or approximately the number that
the term precedes. In determining whether a number is near to or
approximately a specifically recited number, the near or
approximating unrequited number may be a number, which, in the
context in which it is presented, provides the substantial
equivalent of the specifically recited number.
[0128] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
any methods and materials similar or equivalent to those described
herein can also be used in the practice or testing of the present
invention, representative illustrative methods and materials are
now described.
[0129] All publications and patents cited in this specification are
herein incorporated by reference as if each individual publication
or patent were specifically and individually indicated to be
incorporated by reference and are incorporated herein by reference
to disclose and describe the methods and/or materials in connection
with which the publications are cited. The citation of any
publication is for its disclosure prior to the filing date and
should not be construed as an admission that the present invention
is not entitled to antedate such publication by virtue of prior
invention. Further, the dates of publication provided may be
different from the actual publication dates which may need to be
independently confirmed.
[0130] It is noted that, as used herein and in the appended claims,
the singular forms "a," "an," and "the" include plural references
unless the context clearly dictates otherwise. It is further noted
that the claims may be drafted to exclude any optional element. As
such, this statement is intended to serve as antecedent basis for
use of such exclusive terminology as "solely," "only" and the like
in connection with the recitation of claim elements, or use of a
"negative" limitation.
[0131] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope or spirit of the present invention. Any recited
method can be carried out in the order of events recited or in any
other order which is logically possible.
Compositions, Methods, and Systems
[0132] In one aspect, there are provided methods and systems that
relate to the oxidation of metal ions from a lower oxidation state
to a higher oxidation state in the anode chamber of the
electrochemical cell. The metal ions formed with the higher
oxidation state may be used as is or are used for commercial
purposes such as, but not limited to, chemical synthesis reactions,
reduction reactions etc. In one aspect, the electrochemical cells
described herein provide an efficient and low voltage system where
the metal compound such as metal halide, e.g., metal chloride or a
metal sulfate with the higher oxidation state produced by the anode
can be used for other purposes, such as, but not limited to,
generation of hydrogen chloride, hydrochloric acid, hydrogen
bromide, hydrobromic acid, hydrogen iodide, hydroiodic acid, or
sulfuric acid from hydrogen gas and/or generation of
halohydrocarbons or sulfohydrocarbons from hydrocarbons.
[0133] The "halohydrocarbons" or "halogenated hydrocarbon" as used
herein, include halo substituted hydrocarbons where halo may be any
number of halogens that can be attached to the hydrocarbon based on
permissible valency. The halogens include fluoro, chloro, bromo,
and iodo. The examples of halohydrocarbons include
chlorohydrocarbons, bromohydrocarbons, and iodohydrocarbons. The
chlorohydrocarbons include, but not limited to,
monochlorohydrocarbons, dichlorohydrocarbons,
trichlorohydrocarbons, etc. For metal halides, such as, but not
limited to, metal bromide and metal iodide, the metal bromide or
metal iodide with the higher oxidation state produced by the anode
chamber can be used for other purposes, such as, but not limited
to, generation of hydrogen bromide or hydrogen iodide and/or
generation of bromo or iodohydrocarbons, such as, but not limited
to, monobromohydrocarbons, dibromohydrocarbons,
tribromohydrocarbons, monoiodohydrocarbons, diiodohydrocarbons,
triiodohydrocarbons, etc. In some embodiments, the metal ion in the
higher oxidation state may be sold as is in the commercial
market.
[0134] The "sulfohydrocarbons" as used herein include hydrocarbons
substituted with one or more of --SO.sub.3H or --OSO.sub.2OH based
on permissible valency.
[0135] The electrochemical cell of the invention may be any
electrochemical cell where the metal ion in the lower oxidation
state is converted to the metal ion in the higher oxidation state
in the anode chamber. In such electrochemical cells, cathode
reaction may be any reaction that does or does not form an alkali
in the cathode chamber. Such cathode consumes electrons and carries
out any reaction including, but not limited to, the reaction of
water to form hydroxide ions and hydrogen gas or reaction of oxygen
gas and water to form hydroxide ions or reduction of protons from
an acid such as hydrochloric acid to form hydrogen gas or reaction
of protons from hydrochloric acid and oxygen gas to form water.
[0136] In some embodiments, the electrochemical cells may include
production of an alkali in the cathode chamber of the cell. The
alkali generated in the cathode chamber may be used as is for
commercial purposes or may be treated with divalent cations to form
divalent cation containing carbonates/bicarbonates. In some
embodiments, the alkali generated in the cathode chamber may be
used to sequester or capture carbon dioxide. The carbon dioxide may
be present in flue gas emitted by various industrial plants. The
carbon dioxide may be sequestered in the form of carbonate and/or
bicarbonate products. In some embodiments, the metal compound with
metal in the higher oxidation state may be withdrawn from the anode
chamber and is used for any commercial process that is known to
skilled artisan in the art. Therefore, both the anode electrolyte
as well as the cathode electrolyte can be used for generating
products that may be used for commercial purposes thereby providing
a more economical, efficient, and less energy intensive
process.
[0137] In some embodiments, the metal compound produced by the
anode chamber may be used as is or may be purified before reacting
with hydrogen gas, unsaturated hydrocarbon, or saturated
hydrocarbon for the generation of hydrogen chloride, hydrochloric
acid, hydrogen bromide, hydrobromic acid, hydrogen iodide, or
hydroiodic acid, sulfuric acid, and/or halohydrocarbon or
sulfohydrocarbon, respectively. In some embodiments, the metal
compound may be used on-site where hydrogen gas is generated and/or
in some embodiments, the metal compound withdrawn from the anode
chamber may be transferred to a site where hydrogen gas is
generated and hydrogen chloride, hydrochloric acid, hydrogen
bromide, hydrobromic acid, hydrogen iodide, or hydroiodic acid are
formed from it. In some embodiments, the metal compound may be
formed in the electrochemical system and used on-site where an
unsaturated hydrocarbon such as, but not limited to, ethylene gas
is generated or transferred to and/or in some embodiments, the
metal compound withdrawn from the anode chamber may be transferred
to a site where an unsaturated hydrocarbon such as, but not limited
to, ethylene gas is generated or transferred to and
halohydrocarbon, e.g., chlorohydrocarbon is formed from it. In some
embodiments, the ethylene gas generating facility is integrated
with the electrochemical system of the invention to simultaneously
produce the metal compound in the higher oxidation state and the
ethylene gas and treat them with each other to form a product, such
as ethylene dichloride (EDC). The ethylene dichloride may also be
known as 1,2-dichloroethane, dichloroethane, 1,2-ethylene
dichloride, glycol dichloride, freon 150, borer sol, brocide,
destruxol borer-sol, dichlor-mulsion, dutch oil, or granosan. In
some embodiments, the electrochemical system of the invention is
integrated with vinyl chloride monomer (VCM) production facility or
polyvinylchloride (PVC) production facility such that the EDC
formed via the systems and methods of the invention is used in VCM
and/or PVC production.
[0138] The electrochemical systems and methods described herein
provide one or more advantages over conventional electrochemical
systems known in the art, including, but not limited to, no
requirement of gas diffusion anode; higher cell efficiency; lower
voltages; platinum free anode; sequestration of carbon dioxide;
green and environment friendly chemicals; and/or formation of
various commercially viable products.
[0139] The systems and methods of the invention provide an
electrochemical cell that produces various products, such as, but
not limited to, metal salts formed at the anode, the metal salts
used to form various other chemicals, alkali formed at the cathode,
alkali used to form various other products, and/or hydrogen gas
formed at the cathode. All of such products have been defined
herein and may be called "green chemicals" since such chemicals are
formed using the electrochemical cell that runs at low voltage or
energy and high efficiency. The low voltage or less energy
intensive process described herein would lead to lesser emission of
carbon dioxide as compared to conventional methods of making
similar chemicals or products. In some embodiments, the chemicals
or products are formed by the capture of carbon dioxide from flue
gas in the alkali generated at the cathode, such as, but not
limited to, carbonate and bicarbonate products. Such carbonate and
bicarbonate products are "green chemicals" as they reduce the
pollution and provide cleaner environment.
Metal
[0140] The "metal ion" or "metal" as used herein, includes any
metal ion capable of being converted from lower oxidation state to
higher oxidation state. Examples of metal ions include, but not
limited to, iron, chromium, copper, tin, silver, cobalt, uranium,
lead, mercury, vanadium, bismuth, titanium, ruthenium, osmium,
europium, zinc, cadmium, gold, nickel, palladium, platinum,
rhodium, iridium, manganese, technetium, rhenium, molybdenum,
tungsten, niobium, tantalum, zirconium, hafnium, and combination
thereof. In some embodiments, the metal ions include, but not
limited to, iron, copper, tin, chromium, or combination thereof. In
some embodiments, the metal ion is copper. In some embodiments, the
metal ion is tin. In some embodiments, the metal ion is iron. In
some embodiments, the metal ion is chromium. In some embodiments,
the metal ion is platinum. The "oxidation state" as used herein,
includes degree of oxidation of an atom in a substance. For
example, in some embodiments, the oxidation state is the net charge
on the ion. Some examples of the reaction of the metal ions at the
anode are as shown in Table I below (SHE is standard hydrogen
electrode). The theoretical values of the anode potential are also
shown. It is to be understood that some variation from these
voltages may occur depending on conditions, pH, concentrations of
the electrolytes, etc and such variations are well within the scope
of the invention.
TABLE-US-00001 TABLE I Anode Potential Anode Reaction (V vs. SHE)
Ag.sup.+ .fwdarw. Ag.sup.2+ + e.sup.- -1.98 Co.sup.2+ .fwdarw.
Co.sup.3+ + e.sup.- -1.82 Pb.sup.2.sup.+ .fwdarw. Pb.sup.4+ +
2e.sup.- -1.69 Ce.sup.3+ .fwdarw. Ce.sup.4+ + e.sup.- -1.44
2Cr.sup.3+ + 7H.sub.2O .fwdarw. Cr.sub.2O.sub.7.sup.2- + 14H.sup.+
+ 6e.sup.- -1.33 Ti.sup.+ .fwdarw. Ti.sup.3+ + 2e.sup.- -1.25
Hg.sub.2.sup.2+ .fwdarw. 2Hg.sup.2+ + 2e.sup.- -0.91 Fe.sup.2+
.fwdarw. Fe.sup.3+ + e.sup.- -0.77 V.sup.3+ + H.sub.2O .fwdarw.
VO.sup.2+ + 2H.sup.+ + e.sup.- -0.34 U.sup.4+ + 2H.sub.2O.fwdarw.
UO.sup.2+ + 4H.sup.+ + e.sup.- -0.27 Bi.sup.+ .fwdarw. Bi.sup.3+ +
2e.sup.- -0.20 Ti.sup.3+ + H.sub.2O .fwdarw. TiO.sup.2+ + 2H.sup.+
+ e.sup.- -0.19 Cu.sup.+ .fwdarw. Cu.sup.2+ + e.sup.- -0.16
UO.sub.2.sup.+ .fwdarw. UO.sub.2.sup.2+ + e.sup.- -0.16
Sn.sup.2.sup.+ .fwdarw. Sn.sup.4+ + 2e.sup.- -0.15
Ru(NH.sub.3).sub.6.sup.2+ .fwdarw. Ru(NH.sub.3).sub.6.sup.3+ +
e.sup.- -0.10 V.sup.2+ .fwdarw. V.sup.3+ + e.sup.- +0.26 Eu.sup.2+
.fwdarw. Eu.sup.3+ + e.sup.- +0.35 Cr.sup.2+ .fwdarw. Cr.sup.3+ +
e.sup.- +0.42 U.sup.3+ .fwdarw. U.sup.4+ + e.sup.- +0.52
[0141] The metal ion may be present as a compound of the metal or
an alloy of the metal or combination thereof. In some embodiments,
the anion attached to the metal is same as the anion of the
electrolyte. For example, for sodium or potassium chloride used as
an electrolyte, a metal chloride, such as, but not limited to, iron
chloride, copper chloride, tin chloride, chromium chloride etc. is
used as the metal compound. For example, for sodium or potassium
sulfate used as an electrolyte, a metal sulfate, such as, but not
limited to, iron sulfate, copper sulfate, tin sulfate, chromium
sulfate etc. is used as the metal compound. For example, for sodium
or potassium bromide used as an electrolyte, a metal bromide, such
as, but not limited to, iron bromide, copper bromide, tin bromide
etc. is used as the metal compound.
[0142] In some embodiments, the anion of the electrolyte may be
partially or fully different from the anion of the metal. For
example, in some embodiments, the anion of the electrolyte may be a
sulfate whereas the anion of the metal may be a chloride. In such
embodiments, it may be desirable to have less concentration of the
chloride ions in the electrochemical cell. For example, in some
embodiments, the higher concentration of chloride ions in the anode
electrolyte, due to chloride of the electrolyte and the chloride of
the metal, may result in undesirable ionic species in the anode
electrolyte. This may be avoided by utilizing an electrolyte that
contains ions other than chloride. In some embodiments, the anode
electrolyte may be a combination of ions similar to the metal anion
and anions different from the metal ion. For example, the anode
electrolyte may be a mix of sulfate ions as well as chloride ions
when the metal anion is chloride. In such embodiments, it may be
desirable to have sufficient concentration of chloride ions in the
electrolyte to dissolve the metal salt but not high enough to cause
undesirable ionic speciation.
[0143] In some embodiments, the electrolyte and/or the metal
compound are chosen based on the desired end product. For example,
if HCl is desired from the reaction between the hydrogen gas and
the metal compound then metal chloride is used as the metal
compound and the sodium chloride is used as an electrolyte. For
example, if a brominated hydrocarbon is desired from the reaction
between the metal compound and the hydrocarbon, then a metal
bromide is used as the metal compound and the sodium or potassium
bromide is used as the electrolyte.
[0144] In some embodiments, the metal ions used in the
electrochemical systems described herein, may be chosen based on
the solubility of the metal in the anode electrolyte and/or cell
voltages desired for the metal oxidation from the lower oxidation
state to the higher oxidation state. For example, the voltage
required to oxidize Cr.sup.2+ to Cr.sup.3+ may be lower than that
required for Sn.sup.2+ to Sn.sup.4+, however, the amount of HCl
formed by the reaction of the hydrogen gas with the Cr.sup.3+ may
be lower than the HCl formed with Sn.sup.4+ owing to two chlorine
atoms obtained per tin molecule. Therefore, in some embodiments,
where the lower cell voltages may be desired, the metal ion
oxidation that results in lower cell voltage may be used, such as,
but not limited to Cr.sup.2+. For example, for the reactions where
carbon dioxide is captured by the alkali produced by the cathode
electrolyte, a lower voltage may be desired. In some embodiments,
where a higher amount of the product, such as hydrochloric acid may
be desired, the metal ion that results in higher amount of the
product albeit relatively higher voltages may be used, such as, but
not limited to Sn.sup.2+. For example, the voltage of the cell may
be higher for tin system as compared to the chromium system,
however, the concentration of the acid formed with Sn.sup.4+ may
offset the higher voltage of the system. It is to be understood,
that the products formed by the systems and methods described
herein, such as the acid, halohydrocarbons, sulfohydrocarbons,
carbonate, bicarbonates, etc. are still "green" chemicals as they
are made by less energy intensive processes as compared to energy
input required for conventionally known methods of making the same
products.
[0145] In some embodiments, the metal ion in the lower oxidation
state and the metal ion in the higher oxidation state are both
present in the anode electrolyte. In some embodiments, it may be
desirable to have the metal ion in both the lower oxidation state
and the higher oxidation state in the anode electrolyte. Suitable
ratios of the metal ion in the lower and higher oxidation state in
the anode electrolyte have been described herein. The mixed metal
ion in the lower oxidation state with the metal ion in the higher
oxidation state may assist in lower voltages in the electrochemical
systems and high yield and selectivity in corresponding catalytic
reactions with hydrogen gas or hydrocarbons.
[0146] In some embodiments, the metal ion in the anode electrolyte
is a mixed metal ion. For example, the anode electrolyte containing
the copper ion in the lower oxidation state and the copper ion in
the higher oxidation state may also contain another metal ion such
as, but not limited to, iron. In some embodiments, the presence of
a second metal ion in the anode electrolyte may be beneficial in
lowering the total energy of the electrochemical reaction in
combination with the catalytic reaction.
[0147] Some examples of the metal compounds that may be used in the
systems and methods of the invention include, but are not limited
to, copper (II) sulfate, copper (II) nitrate, copper (I) chloride,
copper (I) bromide, copper (I) iodide, iron (III) sulfate, iron
(III) nitrate, iron (II) chloride, iron (II) bromide, iron (II)
iodide, tin (II) sulfate, tin (II) nitrate, tin (II) chloride, tin
(II) bromide, tin (II) iodide, chromium (III) sulfate, chromium
(III) nitrate, chromium (II) chloride, chromium (II) bromide,
chromium (II) iodide, zinc (II) chloride, zinc (II) bromide,
etc.
Ligands
[0148] In some embodiments, an additive such as a ligand is used in
conjunction with the metal ion to improve the efficiency of the
metal ion oxidation inside the anode chamber and/or improve the
catalytic reactions of the metal ion inside/outside the anode
chamber such as, but not limited to reactions with hydrogen gas,
with unsaturated hydrocarbon, and/or with saturated hydrocarbon. In
some embodiments, the ligand is added along with the metal in the
anode electrolyte. In some embodiments, the ligand is attached to
the metal ion. In some embodiments, the ligand is attached to the
metal ion by covalent, ionic and/or coordinate bonds. In some
embodiments, the ligand is attached to the metal ion through
vanderwaal attractions.
[0149] Accordingly, in some embodiments, there are provided methods
that include contacting an anode with an anode electrolyte;
oxidizing a metal ion from the lower oxidation state to a higher
oxidation state at the anode; adding a ligand to the anode
electrolyte wherein the ligand interacts with the metal ion; and
contacting a cathode with a cathode electrolyte. In some
embodiments, there are provided methods that include contacting an
anode with an anode electrolyte; oxidizing a metal ion from the
lower oxidation state to a higher oxidation state at the anode;
adding a ligand to the anode electrolyte wherein the ligand
interacts with the metal ion; and contacting a cathode with a
cathode electrolyte wherein the cathode produces hydroxide ions,
water, and/or hydrogen gas. In some embodiments, there are provided
methods that include contacting an anode with an anode electrolyte;
oxidizing a metal ion from the lower oxidation state to a higher
oxidation state at the anode; adding a ligand to the anode
electrolyte wherein the ligand interacts with the metal ion;
contacting a cathode with a cathode electrolyte wherein the cathode
produces hydroxide ions, water, and/or hydrogen gas; and contacting
the anode electrolyte containing the ligand and the metal ion in
the higher oxidation state with an unsaturated hydrocarbon,
hydrogen gas, saturated hydrocarbon, or combination thereof.
[0150] In some embodiments, there are provided methods that include
contacting an anode with an anode electrolyte; oxidizing a metal
halide from a lower oxidation state to a higher oxidation state at
the anode; adding a ligand to the metal halide wherein the ligand
interacts with the metal ion; contacting a cathode with a cathode
electrolyte wherein the cathode produces hydroxide ions, water,
and/or hydrogen gas; and halogenating an unsaturated and/or
saturated hydrocarbon with the metal halide in the higher oxidation
state. In some embodiments, the metal halide is metal chloride and
halogenations reaction is chlorination. In some embodiments, such
methods contain a hydrogen gas producing cathode. In some
embodiments, such methods contain an oxygen depolarized cathode. In
some embodiments, the unsaturated hydrocarbon in such methods is a
substituted or an unsubstituted alkene as C.sub.nH.sub.2n where n
is 2-20 (or alkyne or formula I as described further herein), e.g.,
ethylene, propylene, butene etc. In some embodiments, the saturated
hydrocarbon in such methods is a substituted or an unsubstituted
alkane as C.sub.nH.sub.2n+2 where n is 2-20 (or formula III as
described further herein), e.g., methane, ethane, propane, etc. In
some embodiments, the metal in such methods is metal chloride such
as copper chloride. In some embodiments, such methods result in net
energy saving of more than 100 kJ/mol or more than 150 kJ/mol or
more than 200 kJ/mol or between 100-250 kJ/mol or the method
results in the voltage savings of more than 1V (described below and
in FIG. 8C). In some embodiments, the unsaturated hydrocarbon in
such methods is C.sub.2-C.sub.5 alkene such as but not limited to,
ethylene, propylene, isobutylene, 2-butene (cis and/or trans),
pentene etc. or C.sub.2-C.sub.4 alkene such as but not limited to,
ethylene, propylene, isobutylene, 2-butene (cis and/or trans), etc.
In some embodiments, the unsaturated hydrocarbon in such methods is
ethylene and the metal ion in such methods is metal chloride such
as, copper chloride. In such methods, halogenations of the ethylene
forms EDC. In some embodiments, the saturated hydrocarbon in such
methods is ethane and the metal ion in such methods is metal
chloride such as, platinum chloride or copper chloride. In such
methods, halogenation of ethane forms chloroethane or EDC.
[0151] In some embodiments, there are provided systems that include
an anode in contact with an anode electrolyte wherein the anode is
configured to oxidize a metal ion from the lower oxidation state to
a higher oxidation state; a ligand in the anode electrolyte wherein
the ligand is configured to interact with the metal ion; and a
cathode in contact with a cathode electrolyte. In some embodiments,
there are provided systems that include an anode in contact with an
anode electrolyte wherein the anode is configured to oxidize a
metal ion from the lower oxidation state to a higher oxidation
state; a ligand in the anode electrolyte wherein the ligand is
configured to interact with the metal ion; and a cathode in contact
with a cathode electrolyte wherein the cathode is configured to
produce hydroxide ions, water, and/or hydrogen gas. In some
embodiments, there are provided systems that include an anode in
contact with an anode electrolyte wherein the anode is configured
to oxidize a metal ion from the lower oxidation state to a higher
oxidation state; a ligand in the anode electrolyte wherein the
ligand is configured to interact with the metal ion; and a cathode
in contact with a cathode electrolyte wherein the cathode is
configured to form hydroxide ions, water, and/or hydrogen gas; and
a reactor configured to react the anode electrolyte containing the
ligand and the metal ion in the higher oxidation state with an
unsaturated hydrocarbon, hydrogen gas, saturated hydrocarbon, or
combination thereof. In some embodiments, such systems contain an
oxygen depolarized cathode. In some embodiments, such systems
contain a hydrogen gas producing cathode. In some embodiments, such
systems result in net energy saving of more than 100 kJ/mol or more
than 150 kJ/mol or more than 200 kJ/mol or between 100-250 kJ/mol
or the system results in the voltage savings of more than 1V
(described below and in FIG. 8C). In some embodiments, the
unsaturated hydrocarbon in such systems is C.sub.2-C.sub.5 alkene,
such as but not limited to, ethylene, propylene, isobutylene,
2-butene (cis and/or trans), pentene etc. or C.sub.2-C.sub.4
alkene, such as but not limited to, ethylene, propylene,
isobutylene, 2-butene (cis and/or trans), etc. In some embodiments,
the unsaturated hydrocarbon in such systems is ethylene. In some
embodiments, the metal in such systems is metal chloride such as
copper chloride. In some embodiments, the unsaturated hydrocarbon
in such systems is ethylene and the metal ion in such systems is
metal chloride such as, copper chloride. In such systems,
halogenations of the ethylene forms EDC. In some embodiments, the
saturated hydrocarbon in such systems is ethane and the metal ion
in such systems is metal chloride such as, platinum chloride,
copper chloride, etc. In such systems, halogenation of ethane forms
chloroethane and/or EDC.
[0152] In some embodiments, the ligand results in one or more of
the following: enhanced reactivity of the metal ion towards the
unsaturated hydrocarbon, saturated hydrocarbon, or hydrogen gas,
enhanced selectivity of the metal ion towards halogenations of the
unsaturated or saturated hydrocarbon, enhanced transfer of the
halogen from the metal ion to the unsaturated hydrocarbon,
saturated hydrocarbon, or the hydrogen gas, reduced redox potential
of the electrochemical cell, enhanced solubility of the metal ion
in the aqueous medium, reduced membrane cross-over of the metal ion
to the cathode electrolyte in the electrochemical cell, reduced
corrosion of the electrochemical cell and/or the reactor, enhanced
separation of the metal ion from the acid solution after reaction
with hydrogen gas (such as size exclusion membranes), enhanced
separation of the metal ion from the halogenated hydrocarbon
solution (such as size exclusion membranes), and combination
thereof.
[0153] In some embodiments, the attachment of the ligand to the
metal ion increases the size of the metal ion sufficiently higher
to prevent its migration through the ion exchange membranes in the
cell. In some embodiments, the anion exchange membrane in the
electrochemical cell may be used in conjunction with the size
exclusion membrane such that the migration of the metal ion
attached to the ligand from the anode electrolyte to the cathode
electrolyte, is prevented. Such membranes are described herein
below. In some embodiments, the attachment of the ligand to the
metal ion increases the solubility of the metal ion in the aqueous
medium. In some embodiments, the attachment of the ligand to the
metal ion reduces the corrosion of the metals in the
electrochemical cell as well as the reactor. In some embodiments,
the attachment of the ligand to the metal ion increases the size of
the metal ion sufficiently higher to facilitate separation of the
metal ion from the acid or from the halogenated hydrocarbon after
the reaction. In some embodiments, the presence and/or attachment
of the ligand to the metal ion may prevent formation of various
halogenated species of the metal ion in the solution and favor
formation of only the desired species. For example, the presence of
the ligand in the copper ion solution may limit the formation of
the various halogenated species of the copper ion, such as, but not
limited to, [CuCl.sub.3].sup.2- or CuCl.sub.2.degree. but favor
formation of Cu.sup.2+/Cu.sup.+ ion. In some embodiments, the
presence and/or attachment of the ligand in the metal ion solution
reduces the overall voltage of the cell by providing one or more of
the advantages described above.
[0154] The "ligand" as used herein includes any ligand capable of
enhancing the properties of the metal ion. In some embodiments,
ligands include, but not limited to, substituted or unsubstituted
aliphatic phosphine, substituted or unsubstituted aromatic
phosphine, substituted or unsubstituted amino phosphine,
substituted or unsubstituted crown ether, substituted or
unsubstituted aliphatic nitrogen, substituted or unsubstituted
cyclic nitrogen, substituted or unsubstituted aliphatic sulfur,
substituted or unsubstituted cyclic sulfur, substituted or
unsubstituted heterocyclic, and substituted or unsubstituted
heteroaromatic. Some examples of the ligands are illustrated in
FIGS. 20, 25A, and 25B.
Substituted or Unsubstituted Aliphatic Nitrogen
[0155] In some embodiments, the ligand is a substituted or
unsubstituted aliphatic nitrogen of formula A:
##STR00008##
wherein n and m independently are 0-2 and R and R.sup.1
independently are H, alkyl, or substituted alkyl. In some
embodiments, alkyl is methyl, ethyl, propyl, i-propyl, butyl,
i-butyl, or pentyl. In some embodiments, the substituted alkyl is
alkyl substituted with one or more of a group including alkenyl,
halogen, amine, substituted amine, and combination thereof. In some
embodiments, the substituted amine is substituted with a group
selected from hydrogen and/or alkyl. Some examples of the ligands
are illustrated in FIG. 20.
[0156] In some embodiments, the ligand is a substituted or
unsubstituted aliphatic nitrogen of formula B:
##STR00009##
wherein R and R.sup.1 independently are H, alkyl, or substituted
alkyl. In some embodiments, alkyl is methyl, ethyl, propyl,
i-propyl, butyl, i-butyl, or pentyl. In some embodiments, the
substituted alkyl is alkyl substituted with one or more of a group
including alkenyl, halogen, amine, substituted amine, and
combination thereof. In some embodiments, the substituted amine is
substituted with a group selected from hydrogen and/or alkyl.
[0157] In some embodiments, the ligand is a substituted or
unsubstituted aliphatic nitrogen donor of formula B, wherein R and
R.sup.1 independently are H, C.sub.1-C.sub.4 alkyl, or substituted
C.sub.1-C.sub.4 alkyl. In some embodiments, C.sub.1-C.sub.4 alkyl
is methyl, ethyl, propyl, i-propyl, butyl, or i-butyl. In some
embodiments, the substituted C.sub.1-C.sub.4 alkyl is
C.sub.1-C.sub.4 alkyl substituted with one or more of a group
including alkenyl, halogen, amine, substituted amine, and
combination thereof. In some embodiments, the substituted amine is
substituted with a group selected from hydrogen and/or
C.sub.1-C.sub.3 alkyl.
[0158] The concentration of the ligand may be chosen based on
various parameters, including but not limited to, concentration of
the metal ion, solubility of the ligand etc. Some examples of
ligands that are substituted or unsubstituted aliphatic nitrogen,
are as illustrated in FIG. 20.
Substituted or Unsubstituted Crown Ether with O, S, P or N
Heteroatoms
[0159] In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C:
##STR00010##
wherein R is independently O, S, P, or N; and n is 0 or 1.
[0160] In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is O and n is 0
or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is S and n is 0
or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is N and n is 0
or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is P and n is 0
or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is O or S, and n
is 0 or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is O or N, and n
is 0 or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is N or S, and n
is 0 or 1. In some embodiments, the ligand is a substituted or
unsubstituted crown ether of formula C, wherein R is N or P, and n
is 0 or 1.
Substituted or Unsubstituted Phosphines
[0161] In some embodiments, the ligand is a substituted or
unsubstituted phosphine of formula D, or an oxide thereof:
##STR00011##
wherein R.sup.1, R.sup.2, and R.sup.3 independently are H, alkyl,
substituted alkyl, alkoxy, substituted alkoxy, aryl, substituted
aryl, heteroaryl, substituted heteroaryl, amine, substituted amine,
cycloalkyl, substituted cycloalkyl, heterocycloalkyl, and
substituted heterocycloalkyl.
[0162] An example of an oxide of formula D is:
##STR00012##
wherein R.sup.1, R.sup.2, and R.sup.3 independently are H, alkyl,
substituted alkyl, alkoxy, substituted alkoxy, aryl, substituted
aryl, heteroaryl, substituted heteroaryl, amine, substituted amine,
cycloalkyl, substituted cycloalkyl, heterocycloalkyl, and
substituted heterocycloalkyl.
[0163] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are alkyl and
substituted alkyl. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are alkyl and substituted alkyl wherein the substituted alkyl is
substituted with group selected from alkoxy, substituted alkoxy,
amine, and substituted amine. In some embodiments of the compound
of formula D, or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3
independently are alkyl and substituted alkyl wherein the
substituted alkyl is substituted with group selected from alkoxy
and amine.
[0164] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are alkoxy and
substituted alkoxy. In some embodiments of the compound of formula
D or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are alkoxy and substituted alkoxy wherein the substituted alkoxy is
substituted with group selected from alkyl, substituted alkyl,
amine, and substituted amine. In some embodiments of the compound
of formula D or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3
independently are alkoxy and substituted alkoxy wherein the
substituted alkoxy is substituted with group selected from alkyl
and amine.
[0165] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are aryl and
substituted aryl. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are aryl and substituted aryl wherein the substituted aryl is
substituted with group selected from alkyl, substituted alkyl,
alkoxy, substituted alkoxy, amine, and substituted amine. In some
embodiments of the compound of formula D or an oxide thereof,
R.sup.1, R.sup.2, and R.sup.3 independently are aryl and
substituted aryl wherein the substituted aryl is substituted with
group selected from alkyl, alkoxy, and amine. In some embodiments
of the compound of formula D or an oxide thereof, R.sup.1, R.sup.2,
and R.sup.3 independently are aryl and substituted aryl wherein the
substituted aryl is substituted with group selected from alkyl and
alkoxy.
[0166] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are heteroaryl
and substituted heteroaryl. In some embodiments of the compound of
formula D or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3
independently are heteroaryl and substituted heteroaryl wherein the
substituted heteroaryl is substituted with a group selected from
alkyl, substituted alkyl, alkoxy, substituted alkoxy, amine, and
substituted amine. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are heteroaryl and substituted heteroaryl wherein the substituted
heteroaryl is substituted with a group selected from alkyl, alkoxy,
and amine.
[0167] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are cycloalkyl
and substituted cycloalkyl. In some embodiments of the compound of
formula D or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3
independently are cycloalkyl and substituted cycloalkyl wherein the
substituted cycloalkyl is substituted with a group selected from
alkyl, substituted alkyl, alkoxy, substituted alkoxy, amine, and
substituted amine. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are cycloalkyl and substituted cycloalkyl wherein the substituted
cycloalkyl is substituted with a group selected from alkyl, alkoxy,
and amine.
[0168] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are
heterocycloalkyl and substituted heterocycloalkyl. In some
embodiments of the compound of formula D or an oxide thereof,
R.sup.1, R.sup.2, and R.sup.3 independently are heterocycloalkyl
and substituted heterocycloalkyl wherein the substituted
heterocycloalkyl is substituted with a group selected from alkyl,
substituted alkyl, alkoxy, substituted alkoxy, amine, and
substituted amine. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are heterocycloalkyl and substituted heterocycloalkyl wherein the
substituted heterocycloalkyl is substituted with a group selected
from alkyl, alkoxy, and amine.
[0169] In some embodiments of the compound of formula D or an oxide
thereof, R.sup.1, R.sup.2, and R.sup.3 independently are amine and
substituted amine. In some embodiments of the compound of formula D
or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently
are amine and substituted amine wherein the substituted amine is
substituted with a group selected from alkyl, substituted alkyl,
alkoxy, and substituted alkoxy. In some embodiments of the compound
of formula D or an oxide thereof, R.sup.1, R.sup.2, and R.sup.3
independently are amine and substituted amine wherein the
substituted amine is substituted with a group selected from alkyl,
and alkoxy. In some embodiments of the compound of formula D or an
oxide thereof, R.sup.1, R.sup.2, and R.sup.3 independently are
amine and substituted amine wherein the substituted amine is
substituted with alkyl.
[0170] In some embodiments, the ligand is a substituted or
unsubstituted phosphine of formula D or an oxide thereof:
##STR00013##
wherein R.sup.1, R.sup.2, and R.sup.3 independently are H, alkyl;
substituted alkyl substituted with a group selected from alkoxy,
substituted alkoxy, amine, and substituted amine; aryl; substituted
aryl substituted with a group selected from alkyl, substituted
alkyl, alkoxy, substituted alkoxy, amine, and substituted amine;
heteroaryl; substituted heteroaryl substituted with a group
selected from alkyl, substituted alkyl, alkoxy, substituted alkoxy,
amine, and substituted amine; amine; substituted amine substituted
with a group selected from alkyl, substituted alkyl, alkoxy, and
substituted alkoxy; cycloalkyl; substituted cycloalkyl substituted
with a group selected from alkyl, substituted alkyl, alkoxy,
substituted alkoxy, amine, and substituted amine; heterocycloalkyl;
and substituted heterocycloalkyl substituted with a group selected
from alkyl, substituted alkyl, alkoxy, substituted alkoxy, amine,
and substituted amine.
[0171] In some embodiments, the ligand is a substituted or
unsubstituted phosphine of formula D or an oxide thereof:
##STR00014##
wherein R.sup.1, R.sup.2, and R.sup.3 independently are H, alkyl;
substituted alkyl substituted with a group selected from alkoxy and
amine; aryl; substituted aryl substituted with a group selected
from alkyl, alkoxy, and amine; heteroaryl; substituted heteroaryl
substituted with a group selected from alkyl, alkoxy, and amine;
amine; substituted amine substituted with a group selected from
alkyl, and alkoxy; cycloalkyl; substituted cycloalkyl substituted
with a group selected from alkyl, alkoxy, and amine;
heterocycloalkyl; and substituted heterocycloalkyl substituted with
a group selected from alkyl, alkoxy, and amine.
Substituted or Unsubstituted Pyridines
[0172] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E:
##STR00015##
wherein R.sup.1 and R.sup.2 independently are H, alkyl, substituted
alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl,
amine, substituted amine, cycloalkyl, substituted cycloalkyl,
heterocycloalkyl, and substituted heterocycloalkyl.
[0173] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E:
##STR00016##
wherein R.sup.1 and R.sup.2 independently are H, alkyl, substituted
alkyl, heteroaryl, substituted heteroaryl, amine, and substituted
amine.
[0174] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E, wherein R.sup.1 and R.sup.2
independently are H, alkyl, and substituted alkyl wherein
substituted alkyl is substituted with a group selected from alkoxy,
substituted alkoxy, amine, and substituted amine. In some
embodiments, the ligand is a substituted or unsubstituted pyridine
of formula E, wherein R.sup.1 and R.sup.2 independently are H,
alkyl, and substituted alkyl wherein substituted alkyl is
substituted with a group selected from amine, and substituted amine
wherein substituted amine is substituted with an alkyl, heteroaryl
or a substituted heteroaryl.
[0175] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E, wherein R.sup.1 and R.sup.2
independently are heteroaryl and substituted heteroaryl. In some
embodiments, the ligand is a substituted or unsubstituted pyridine
of formula E, wherein R.sup.1 and R.sup.2 independently are
heteroaryl and substituted heteroaryl substituted with alkyl,
alkoxy or amine.
[0176] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E, wherein R.sup.1 and R.sup.2
independently are amine and substituted amine. In some embodiments,
the ligand is a substituted or unsubstituted pyridine of formula E,
wherein R.sup.1 and R.sup.2 independently are amine and substituted
amine wherein substituted amine is substituted with an alkyl,
heteroaryl or a substituted heteroaryl.
[0177] In some embodiments, the ligand is a substituted or
unsubstituted pyridine of formula E:
##STR00017##
wherein R.sup.1 and R.sup.2 independently are H; alkyl; substituted
alkyl substituted with a group selected from amine and substituted
amine; heteroaryl; substituted heteroaryl substituted with alkyl,
alkoxy or amine; amine; and substituted amine substituted with an
alkyl, heteroaryl or a substituted heteroaryl.
Substituted or Unsubstituted Dinitriles
[0178] In some embodiments, the ligand is a substituted or
unsubstituted dinitrile of formula F:
##STR00018##
[0179] wherein R is hydrogen, alkyl, or substituted alkyl; n is
0-2; m is 0-3; and k is 1-3.
[0180] In some embodiments, the ligand is a substituted or
unsubstituted dinitrile of formula F, wherein R is hydrogen, alkyl,
or substituted alkyl substituted with alkoxy or amine; n is 0-1; m
is 0-3; and k is 1-3.
[0181] In some embodiments, the ligand is a substituted or
unsubstituted dinitrile of formula F, wherein R is hydrogen or
alkyl; n is 0-1; m is 0-3; and k is 1-3.
[0182] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; and a metal ion.
[0183] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; and a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof.
[0184] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof, a metal ion; and a salt.
[0185] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof; and a salt.
[0186] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof; and a salt comprising
sodium chloride, ammonium chloride, sodium sulfate, ammonium
sulfate, calcium chloride, or combination thereof.
[0187] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion; and a salt comprising sodium
chloride, ammonium chloride, sodium sulfate, ammonium sulfate,
calcium chloride, or combination thereof.
[0188] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof, a metal ion; a salt; and an unsaturated or
saturated hydrocarbon.
[0189] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof a salt; and an
unsaturated or saturated hydrocarbon.
[0190] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof a salt comprising
sodium chloride, ammonium chloride, sodium sulfate, ammonium
sulfate, calcium chloride, or combination thereof; and an
unsaturated or saturated hydrocarbon.
[0191] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion; a salt comprising sodium
chloride, ammonium chloride, sodium sulfate, ammonium sulfate,
calcium chloride, or combination thereof; and an unsaturated or
saturated hydrocarbon.
[0192] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion; a salt comprising sodium
chloride, ammonium chloride, sodium sulfate, ammonium sulfate,
calcium chloride, or combination thereof; and an unsaturated or
saturated hydrocarbon selected from ethylene, propylene, butylenes,
ethane, propane, butane, and combination thereof.
[0193] In one aspect, there is provided a composition comprising an
aqueous medium comprising a ligand selected from substituted or
unsubstituted phosphine, substituted or unsubstituted crown ether,
substituted or unsubstituted aliphatic nitrogen, substituted or
unsubstituted pyridine, substituted or unsubstituted dinitrile, and
combination thereof; a metal ion selected from iron, chromium,
copper, tin, silver, cobalt, uranium, lead, mercury, vanadium,
bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium,
gold, nickel, palladium, platinum, rhodium, iridium, manganese,
technetium, rhenium, molybdenum, tungsten, niobium, tantalum,
zirconium, hafnium, and combination thereof; a salt comprising
sodium chloride, ammonium chloride, sodium sulfate, ammonium
sulfate, calcium chloride, or combination thereof; and an
unsaturated or saturated hydrocarbon selected from ethylene,
propylene, butylenes, ethane, propane, butane, and combination
thereof.
[0194] In some embodiments of the methods and systems provided
herein, the ligand is:
[0195] sulfonated bathocuprine;
[0196] pyridine;
[0197] tris(2-pyridylmethyl)amine;
[0198] glutaronitrile;
[0199] iminodiacetonitrile;
[0200] malononitrile;
[0201] succininitrile;
[0202] tris(diethylamino)phosphine;
[0203] tris(dimethylamino)phosphine;
[0204] tri(2-furyl)phosphine;
[0205] tris(4-methoxyphenyl)phosphine;
[0206] bis(diethylamino)phenylphosphine;
[0207] tris(N,N-tetramethylene)phosphoric acid triamide;
[0208] di-tert-butyl N,N-diisopropyl phosphoramidite;
[0209] diethylphosphoramidate;
[0210] hexamethylphosphoramide;
[0211] diethylenetriamine;
[0212] tris(2-aminoethyl)amine;
[0213] N,N,N',N',N''-pentamethyldiethylenetriamine;
[0214] 15-Crown-5;
[0215] 1,4,8,11-tetrathiacyclotetradecane; and
[0216] salt, or stereoisomer thereof.
[0217] In some embodiments, there is provided a method of using a
ligand, comprising adding a ligand to an anode electrolyte
comprising a metal ion solution and resulting in one or more of
properties including, but not limited to, enhanced reactivity of
the metal ion towards the unsaturated hydrocarbon, saturated
hydrocarbon, or hydrogen gas, enhanced selectivity of the metal ion
towards halogenations of the unsaturated or saturated hydrocarbon,
enhanced transfer of the halogen from the metal ion to the
unsaturated hydrocarbon, saturated hydrocarbon, or the hydrogen
gas, reduced redox potential of the electrochemical cell, enhanced
solubility of the metal ion in the aqueous medium, reduced membrane
cross-over of the metal ion to the cathode electrolyte in the
electrochemical cell, reduced corrosion of the electrochemical cell
and/or the reactor, enhanced separation of the metal ion from the
acid solution after reaction with hydrogen gas, enhanced separation
of the metal ion from the halogenated hydrocarbon solution, and
combination thereof.
[0218] In some embodiments, there is provided a method comprising
improving an efficiency of an electrochemical cell wherein the
electrochemical cell comprises an anode in contact with an anode
electrolyte comprising a metal ion where the anode oxidizes the
metal ion from a lower oxidation state to a higher oxidation state.
In some embodiments, the efficiency relates to the voltage applied
to the electrochemical cell.
[0219] As used herein, "alkenyl" refers to linear or branched
hydrocarbyl having from 2 to 10 carbon atoms and in some
embodiments from 2 to 6 carbon atoms or 2 to 4 carbon atoms and
having at least 1 site of vinyl unsaturation (>C.dbd.C<). For
example, ethenyl, propenyl, 1,3-butadienyl, and the like.
[0220] As used herein, "alkoxy" refers to --O-alkyl wherein alkyl
is defined herein. Alkoxy includes, by way of example, methoxy,
ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, and
n-pentoxy.
[0221] As used herein, "alkyl" refers to monovalent saturated
aliphatic hydrocarbyl groups having from 1 to 10 carbon atoms and,
in some embodiments, from 1 to 6 carbon atoms. "C.sub.xC.sub.y
alkyl" refers to alkyl groups having from x to y carbon atoms. This
term includes, by way of example, linear and branched hydrocarbyl
groups such as methyl (CH.sub.3--), ethyl (CH.sub.3CH.sub.2--),
n-propyl (CH.sub.3CH.sub.2CH.sub.2--), isopropyl
((CH.sub.3).sub.2CH--), n-butyl
(CH.sub.3CH.sub.2CH.sub.2CH.sub.2--), isobutyl
((CH.sub.3).sub.2CHCH.sub.2--), sec-butyl
((CH.sub.3)(CH.sub.3CH.sub.2)CH--), t-butyl ((CH.sub.3).sub.3C--),
n-pentyl (CH.sub.3CH.sub.2CH.sub.2CH.sub.2CH.sub.2--), and
neopentyl ((CH.sub.3).sub.3CCH.sub.2--).
[0222] As used herein, "amino" or "amine" refers to the group
--NH.sub.2.
[0223] As used herein, "aryl" refers to an aromatic group of from 6
to 14 carbon atoms and no ring heteroatoms and having a single ring
(e.g., phenyl) or multiple condensed (fused) rings (e.g., naphthyl
or anthryl).
[0224] As used herein, "cycloalkyl" refers to a saturated or
partially saturated cyclic group of from 3 to 14 carbon atoms and
no ring heteroatoms and having a single ring or multiple rings
including fused, bridged, and spiro ring systems. Examples of
cycloalkyl groups include, for instance, cyclopropyl, cyclobutyl,
cyclopentyl, cyclooctyl, and cyclohexenyl.
[0225] As used herein, "halo" or "halogen" refers to fluoro,
chloro, bromo, and iodo.
[0226] As used herein, "heteroaryl" refers to an aromatic group of
from 1 to 6 heteroatoms selected from the group consisting of
oxygen, nitrogen, and sulfur and includes single ring (e.g.
furanyl) and multiple ring systems (e.g. benzimidazol-2-yl and
benzimidazol-6-yl). The heteroaryl includes, but is not limited to,
pyridyl, furanyl, thienyl, thiazolyl, isothiazolyl, triazolyl,
imidazolyl, isoxazolyl, pyrrolyl, pyrazolyl, pyridazinyl,
pyrimidinyl, benzofuranyl, tetrahydrobenzofuranyl, isobenzofuranyl,
benzothiazolyl, benzoisothiazolyl, benzotriazolyl, indolyl,
isoindolyl, benzoxazolyl, quinolyl, tetrahydroquinolinyl,
isoquinolyl, quinazolinonyl, benzimidazolyl, benzisoxazolyl, or
benzothienyl.
[0227] As used herein, "heterocycloalkyl" refers to a saturated or
partially saturated cyclic group having from 1 to 5 heteroatoms
selected from the group consisting of nitrogen, sulfur, or oxygen
and includes single ring and multiple ring systems including fused,
bridged, and spiro ring systems. The heterocyclyl includes, but is
not limited to, tetrahydropyranyl, piperidinyl,
N-methylpiperidin-3-yl, piperazinyl, N-methylpyrrolidin-3-yl,
3-pyrrolidinyl, 2-pyrrolidon-1-yl, morpholinyl, and
pyrrolidinyl.
[0228] As used herein, "substituted alkoxy" refers to
--O-substituted alkyl wherein substituted alkyl is as defined
herein.
[0229] As used herein, "substituted alkyl" refers to an alkyl group
having from 1 to 5 and, in some embodiments, 1 to 3 or 1 to 2
substituents selected from the group consisting of alkenyl,
halogen, --OH, --COOH, amino, substituted amino, wherein said
substituents are as defined herein.
[0230] As used herein, "substituted amino" or "substituted amine"
refers to the group --NR.sup.10R.sup.11 where R.sup.10 and R.sup.11
are independently selected from the group consisting of hydrogen,
alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, and
substituted heteroaryl.
[0231] As used herein, "substituted aryl" refers to aryl groups
which are substituted with 1 to 8 and, in some embodiments, 1 to 5,
1 to 3, or 1 to 2 substituents selected from the group consisting
of alkyl, substituted alkyl, alkoxy, substituted alkoxy, amine,
substituted amine, alkenyl, halogen, --OH, and --COOH, wherein said
substituents are as defined herein.
[0232] As used herein, "substituted cycloalkyl" refers to a
cycloalkyl group, as defined herein, having from 1 to 8, or 1 to 5,
or in some embodiments 1 to 3 substituents selected from the group
consisting of alkyl, substituted alkyl, alkoxy, substituted alkoxy,
amine, substituted amine, alkenyl, halogen, --OH, and --COOH,
wherein said substituents are as defined herein.
[0233] As used herein, "substituted heteroaryl" refers to
heteroaryl groups that are substituted with from 1 to 5, or 1 to 3,
or 1 to 2 substituents selected from the group consisting of the
substituents defined for substituted aryl.
[0234] As used herein, "substituted heterocycloalkyl" refers to
heterocyclic groups, as defined herein, that are substituted with
from 1 to 5 or in some embodiments 1 to 3 of the substituents as
defined for substituted cycloalkyl.
[0235] It is understood that in all substituted groups defined
above, polymers arrived at by defining substituents with further
substituents to themselves (e.g., substituted aryl having a
substituted aryl group as a substituent which is itself substituted
with a substituted aryl group, etc.) are not intended for inclusion
herein. In such cases, the maximum number of such substitutions is
three. Similarly, it is understood that the above definitions are
not intended to include impermissible substitution patterns (e.g.,
methyl substituted with 5 chloro groups). Such impermissible
substitution patterns are well known to the skilled artisan.
[0236] In some embodiments, the concentration of the ligand in the
electrochemical cell is dependent on the concentration of the metal
ion in the lower and/or the higher oxidation state. In some
embodiments, the concentration of the ligand is between 0.25M-5M;
or between 0.25M-4M; or between 0.25M-3M; or between 0.5M-5M; or
between 0.5M-4M; or between 0.5M-3M; or between 0.5M-2.5M; or
between 0.5M-2M; or between 0.5M-1.5M; or between 0.5M-1M; or
between 1M-2M; or between 1.5M-2.5M; or between 1.5M-2M.
[0237] In some embodiments, the ratio of the concentration of the
ligand and the concentration of the Cu(I) ion is between 1:1 to
4:1; or between 1:1 to 3:1; or between 1:1 to 2:1; or is 1:1; or
2:1, or 3:1, or 4:1.
[0238] In some embodiments, the solution used in the catalytic
reaction, i.e., the reaction of the metal ion in the higher
oxidation state with the unsaturated or saturated hydrocarbon, and
the solution used in the electrochemical reaction, contain the
concentration of the metal ion in the higher oxidation state, such
as Cu(II), between 4.5M-7M, the concentration of the metal ion in
the lower oxidation state, such as Cu(I), between 0.25M-1.5M, and
the concentration of the ligand between 0.25M-6M. In some
embodiments, the concentration of the sodium chloride in the
solution may affect the solubility of the ligand and/or the metal
ion; the yield and selectivity of the catalytic reaction; and/or
the efficiency of the electrochemical cell. Accordingly, in some
embodiments, the concentration of sodium chloride in the solution
is between 1M-3M. In some embodiments, the solution used in the
catalytic reaction, i.e., the reaction of the metal ion in the
higher oxidation state with the unsaturated or saturated
hydrocarbon, and the solution used in the electrochemical reaction,
contain the concentration of the metal ion in the higher oxidation
state, such as Cu(II), between 4.5M-7M, the concentration of the
metal ion in the lower oxidation state, such as Cu(I), between
0.25M-1.5M, the concentration of the ligand between 0.25M-6M, and
the concentration of sodium chloride between 1M-3M.
Electrochemical Methods and Systems
[0239] In one aspect, there are provided methods including
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting the metal ion from a lower oxidation
state to a higher oxidation state in the anode chamber; and
contacting a cathode with a cathode electrolyte in a cathode
chamber. In one aspect, there are provided methods including
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting the metal ion from a lower oxidation
state to a higher oxidation state in the anode chamber; contacting
a cathode with a cathode electrolyte in a cathode chamber; and
forming an alkali, water, and/or hydrogen gas in the cathode
chamber. In one aspect, there are provided methods including
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting the metal ion from a lower oxidation
state to a higher oxidation state in the anode chamber; and
treating the metal ion in the higher oxidation state with an
unsaturated or saturated hydrocarbon. In some embodiments, the
treatment of the metal ion in the higher oxidation state with the
unsaturated or saturated hydrocarbon results in the formation of
halohydrocarbons. In some embodiments, the treatment of the metal
ion in the higher oxidation state with an unsaturated or saturated
hydrocarbon, is inside the anode chamber. In some embodiments, the
treatment of the metal ion in the higher oxidation state with an
unsaturated or saturated hydrocarbon, is outside the anode chamber.
In some embodiments, the cathode is an oxygen depolarized
cathode.
[0240] Some embodiments of the electrochemical cells are as
illustrated in the figures and described herein. It is to be
understood that the figures are for illustration purposes only and
that variations in the reagents and set up are well within the
scope of the invention. All the electrochemical methods and systems
described herein do not produce chlorine gas as is found in the
chlor-alkali systems. All the systems and methods related to the
halogenation or sulfonation of the unsaturated or saturated
hydrocarbon, do not use oxygen gas in the catalytic reactor.
[0241] In some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting or oxidizing the metal ion from a lower
oxidation state to a higher oxidation state at the anode; and
contacting a cathode with a cathode electrolyte in a cathode
chamber; and forming an alkali, water, and/or hydrogen gas at the
cathode. In some embodiments, there are provided methods that
include contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; oxidizing the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte in a cathode
chamber; forming an alkali, water, and/or hydrogen gas at the
cathode; and contacting the anode electrolyte comprising metal ion
in the higher oxidation state with an unsaturated and/or saturated
hydrocarbon to form halogenated hydrocarbon, or contacting the
anode electrolyte comprising metal ion in the higher oxidation
state with hydrogen gas to form an acid, or combination of
both.
[0242] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode chamber is configured to
convert the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising a cathode in
contact with a cathode electrolyte. In another aspect, there are
provided systems including an anode chamber containing an anode in
contact with a metal ion in an anode electrolyte, wherein the anode
chamber is configured to convert the metal ion from a lower
oxidation state to a higher oxidation state; and a cathode chamber
containing a cathode in contact with a cathode electrolyte, wherein
the cathode chamber is configured to produce an alkali, water,
and/or hydrogen gas. In some embodiments, there are provided
systems that include an anode chamber comprising an anode in
contact with a metal ion in an anode electrolyte, wherein the anode
is configured to convert the metal ion from a lower oxidation state
to a higher oxidation state; and a cathode chamber comprising a
cathode in contact with a cathode electrolyte wherein the cathode
is configured to form an alkali, water, and/or hydrogen gas in the
cathode electrolyte; and a reactor operably connected to the anode
chamber and configured to contact the anode electrolyte comprising
metal ion in the higher oxidation state with an unsaturated and/or
saturated hydrocarbon and/or hydrogen gas to form halogenated
hydrocarbon or acid, respectively. In another aspect, there are
provided systems including an anode chamber comprising an anode in
contact with a metal ion in an anode electrolyte wherein the anode
chamber is configured to convert the metal ion from a lower
oxidation state to a higher oxidation state and an unsaturated
and/or saturated hydrocarbon delivery system configured to deliver
the unsaturated and/or saturated hydrocarbon to the anode chamber
wherein the anode chamber is also configured to convert the
unsaturated and/or saturated hydrocarbon to halogenated
hydrocarbon.
[0243] As illustrated in FIG. 1A, the electrochemical system 100A
includes an anode chamber with an anode in contact with an anode
electrolyte where the anode electrolyte contains metal ions in
lower oxidation state (represented as M.sup.L+) which are converted
by the anode to metal ions in higher oxidation state (represented
as M.sup.H+). The metal ion may be in the form of a sulfate,
chloride, bromide, or iodide.
[0244] As used herein "lower oxidation state" represented as L+ in
M.sup.L+ includes the lower oxidation state of the metal. For
example, lower oxidation state of the metal ion may be 1+, 2+, 3+,
4+, or 5+. As used herein "higher oxidation state" represented as
H+ in M.sup.H+ includes the higher oxidation state of the metal.
For example, higher oxidation state of the metal ion may be 2+, 3+,
4+, 5+, or 6+.
[0245] The electron(s) generated at the anode are used to drive the
reaction at the cathode. The cathode reaction may be any reaction
known in the art. The anode chamber and the cathode chamber may be
separated by an ion exchange membrane (IEM) that may allow the
passage of ions, such as, but not limited to, sodium ions in some
embodiments to the cathode electrolyte if the anode electrolyte is
sodium chloride or sodium sulfate etc. containing metal halide.
Some reactions that may occur at the cathode include, but not
limited to, reaction of water to form hydroxide ions and hydrogen
gas, reaction of oxygen gas and water to form hydroxide ions,
reduction of HCl to form hydrogen gas; or reaction of HCl and
oxygen gas to form water.
[0246] As illustrated in FIG. 1B, the electrochemical system 100B
includes a cathode chamber with a cathode in contact with the
cathode electrolyte that forms hydroxide ions in the cathode
electrolyte. The electrochemical system 100B also includes an anode
chamber with an anode in contact with the anode electrolyte where
the anode electrolyte contains metal ions in lower oxidation state
(represented as M.sup.L+) which are converted by the anode to metal
ions in higher oxidation state (represented as M.sup.H+). The
electron(s) generated at the anode are used to drive the reaction
at the cathode. The anode chamber and the cathode chamber are
separated by an ion exchange membrane (IEM) that allows the passage
of sodium ions to the cathode electrolyte if the anode electrolyte
is sodium chloride, sodium bromide, sodium iodide, sodium sulfate,
ammonium chloride etc. or an equivalent solution containing the
metal halide. In some embodiments, the ion exchange membrane allows
the passage of anions, such as, but not limited to, chloride ions,
bromide ions, iodide ions, or sulfate ions to the anode electrolyte
if the cathode electrolyte is e.g., sodium chloride, sodium
bromide, sodium iodide, or sodium sulfate or an equivalent
solution. The sodium ions combine with hydroxide ions in the
cathode electrolyte to form sodium hydroxide. The anions combine
with metal ions to form metal halide or metal sulfate. It is to be
understood that the hydroxide forming cathode, as illustrated in
FIG. 1B is for illustration purposes only and other cathodes such
as, cathode reducing HCl to form hydrogen gas or cathode reacting
both HCl and oxygen gas to form water, are equally applicable to
the systems. Such cathodes have been described herein.
[0247] In some embodiments, the electrochemical systems of the
invention include one or more ion exchange membranes. Accordingly,
in some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; oxidizing the metal ion from a lower oxidation state
to a higher oxidation state at the anode; contacting a cathode with
a cathode electrolyte in a cathode chamber; forming an alkali,
water, and/or hydrogen gas at the cathode; and separating the
cathode and the anode by at least one ion exchange membrane. In
some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; oxidizing the metal ion from a lower oxidation state
to a higher oxidation state at the anode; contacting a cathode with
a cathode electrolyte in a cathode chamber; forming an alkali,
water, and/or hydrogen gas at the cathode; separating the cathode
and the anode by at least one ion exchange membrane; and contacting
the anode electrolyte comprising metal ion in the higher oxidation
state with an unsaturated and/or saturated hydrocarbon to form
halogenated hydrocarbon, or contacting the anode electrolyte
comprising metal ion in the higher oxidation state with hydrogen
gas to form an acid, or combination of both. In some embodiments,
the ion exchange membrane is a cation exchange membrane (CEM), an
anion exchange membrane (AEM); or combination thereof.
[0248] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode is configured to convert
the metal ion from a lower oxidation state to a higher oxidation
state; a cathode chamber comprising a cathode in contact with a
cathode electrolyte, wherein the cathode is configured to produce
an alkali, water, and/or hydrogen gas; and at least one ion
exchange membrane separating the cathode and the anode. In some
embodiments, there are provided systems that include an anode
chamber comprising an anode in contact with a metal ion in an anode
electrolyte, wherein the anode is configured to convert the metal
ion from a lower oxidation state to a higher oxidation state; a
cathode chamber comprising a cathode in contact with a cathode
electrolyte, wherein the cathode is configured to produce an
alkali, water, and/or hydrogen gas; at least one ion exchange
membrane separating the cathode and the anode; and a reactor
operably connected to the anode chamber and configured to contact
the anode electrolyte comprising metal ion in the higher oxidation
state with an unsaturated and/or saturated hydrocarbon and/or
hydrogen gas to form a halogenated hydrocarbon and acid,
respectively. In some embodiments, the ion exchange membrane is a
cation exchange membrane (CEM), an anion exchange membrane (AEM);
or combination thereof.
[0249] As illustrated in FIG. 2, the electrochemical system 200
includes a cathode in contact with a cathode electrolyte and an
anode in contact with an anode electrolyte. The cathode forms
hydroxide ions in the cathode electrolyte and the anode converts
metal ions from lower oxidation state (M.sup.L+) to higher
oxidation state (M.sup.H+). The anode and the cathode are separated
by an anion exchange membrane (AEM) and a cation exchange membrane
(CEM). A third electrolyte (e.g., sodium chloride, sodium bromide,
sodium iodide, sodium sulfate, ammonium chloride, or combination
thereof or an equivalent solution) is disposed between the AEM and
the CEM. The sodium ions from the third electrolyte pass through
CEM to form sodium hydroxide in the cathode chamber and the halide
anions such as, chloride, bromide or iodide ions, or sulfate
anions, from the third electrolyte pass through the AEM to form a
solution for metal halide or metal sulfate in the anode chamber.
The metal halide or metal sulfate formed in the anode electrolyte
is then delivered to a reactor for reaction with hydrogen gas or an
unsaturated or saturated hydrocarbon to generate hydrogen chloride,
hydrochloric acid, hydrogen bromide, hydrobromic acid, hydrogen
iodide, or hydroiodic acid and/or halohydrocarbons, respectively.
The third electrolyte, after the transfer of the ions, can be
withdrawn from the middle chamber as depleted ion solution. For
example, in some embodiments when the third electrolyte is sodium
chloride solution, then after the transfer of the sodium ions to
the cathode electrolyte and transfer of chloride ions to the anode
electrolyte, the depleted sodium chloride solution may be withdrawn
from the middle chamber. The depleted salt solution may be used for
commercial purposes or may be transferred to the anode and/or
cathode chamber as an electrolyte or concentrated for re-use as the
third electrolyte. In some embodiments, the depleted salt solution
may be useful for preparing desalinated water. It is to be
understood that the hydroxide forming cathode, as illustrated in
FIG. 2 is for illustration purposes only and other cathodes such
as, cathode reducing HCl to form hydrogen gas or cathode reacting
both HCl and oxygen gas to form water, are equally applicable to
the systems and have been described further herein.
[0250] In some embodiments, the two ion exchange membranes, as
illustrated in FIG. 2, may be replaced by one ion exchange membrane
as illustrated in FIG. 1A or 1B. In some embodiments, the ion
exchange membrane is an anion exchange membrane, as illustrated in
FIG. 3A. In such embodiments, the cathode electrolyte may be a
sodium halide, sodium sulfate or an equivalent solution and the AEM
is such that it allows the passage of anions to the anode
electrolyte but prevents the passage of metal ions from the anode
electrolyte to the cathode electrolyte. In some embodiments, the
ion exchange membrane is a cation exchange membrane, as illustrated
in FIG. 3B. In such embodiments, the anode electrolyte may be a
sodium halide, sodium sulfate or an equivalent solution containing
the metal halide solution or an equivalent solution and the CEM is
such that it allows the passage of sodium cations to the cathode
electrolyte but prevents the passage of metal ions from the anode
electrolyte to the cathode electrolyte. In some embodiments, the
use of one ion exchange membrane instead of two ion exchange
membranes may reduce the resistance offered by multiple IEMs and
may facilitate lower voltages for running the electrochemical
reaction. Some examples of the suitable anion exchange membranes
are provided herein.
[0251] In some embodiments, the cathode used in the electrochemical
systems of the invention, is a hydrogen gas producing cathode.
Accordingly, in some embodiments, there are provided methods that
include contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; oxidizing the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte in a cathode
chamber; forming an alkali and hydrogen gas at the cathode. In some
embodiments, there are provided methods that include contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
oxidizing the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a cathode with a cathode
electrolyte in a cathode chamber; forming an alkali and hydrogen
gas at the cathode; and contacting the anode electrolyte comprising
metal ion in the higher oxidation state with an unsaturated or
saturated hydrocarbon to form halogenated hydrocarbon, or
contacting the anode electrolyte comprising metal ion in the higher
oxidation state with hydrogen gas to form an acid, or combination
of both. In some embodiments, the method further includes
separating the cathode and the anode by at least one ion exchange
membrane. In some embodiments, the ion exchange membrane is a
cation exchange membrane (CEM), an anion exchange membrane (AEM);
or combination thereof. In some embodiments, the above recited
method includes an anode that does not form a gas. In some
embodiments, the method includes an anode that does not use a
gas.
[0252] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode is configured to convert
the metal ion from a lower oxidation state to a higher oxidation
state; and a cathode chamber comprising a cathode in contact with a
cathode electrolyte, wherein the cathode is configured to produce
an alkali and hydrogen gas. In some embodiments, there are provided
systems that include an anode chamber comprising an anode in
contact with a metal ion in an anode electrolyte, wherein the anode
is configured to convert the metal ion from a lower oxidation state
to a higher oxidation state; and a cathode chamber comprising a
cathode in contact with a cathode electrolyte, wherein the cathode
is configured to produce an alkali and hydrogen gas; and a reactor
operably connected to the anode chamber and configured to contact
the anode electrolyte comprising metal ion in the higher oxidation
state with an unsaturated or saturated hydrocarbon and/or hydrogen
gas to form a halogenated hydrocarbon and acid, respectively. In
some embodiments, the system is configured to not produce a gas at
the anode. In some embodiments, the system is configured to not use
a gas at the anode. In some embodiments, the system further
includes at least one ion exchange membrane separating the cathode
and the anode. In some embodiments, the ion exchange membrane is a
cation exchange membrane (CEM), an anion exchange membrane (AEM);
or combination thereof.
[0253] For example, as illustrated in FIG. 4A, the electrochemical
system 400 includes a cathode in contact with the cathode
electrolyte 401 where the hydroxide is formed in the cathode
electrolyte. The system 400 also includes an anode in contact with
the anode electrolyte 402 that converts metal ions in the lower
oxidation state (M.sup.L+) to metal ions in the higher oxidation
states (M.sup.H+). Following are the reactions that take place at
the cathode and the anode:
[0254] H.sub.2O+e.sup.-.fwdarw.1/2H.sub.2+OH.sup.- (cathode)
[0255] M.sup.L+.fwdarw.M.sup.H++xe.sup.- (anode where x=1-3)
[0256] For example, Fe.sup.2+.fwdarw.Fe.sup.3++e.sup.- (anode)
[0257] Cr.sup.2+.fwdarw.Cr.sup.3++e.sup.- (anode)
[0258] Sn.sup.2+.fwdarw.Sn.sup.4++2e.sup.- (anode)
[0259] Cu.sup.+.fwdarw.Cu.sup.2++e.sup.- (anode)
[0260] As illustrated in FIG. 4A, the electrochemical system 400
includes a cathode that forms hydroxide ions and hydrogen gas at
the cathode. The hydrogen gas may be vented out or captured and
stored for commercial purposes. In some embodiments, the hydrogen
released at the cathode may be subjected to halogenations or
sulfonation (including sulfation) with the metal halide or metal
sulfate formed in the anode electrolyte to form hydrogen chloride,
hydrochloric acid, hydrogen bromide, hydrobromic acid, hydrogen
iodide, hydroiodic acid, or sulfuric acid. Such reaction is
described in detail herein. The M.sup.H+ formed at the anode
combines with chloride ions to form metal chloride in the higher
oxidation state such as, but not limited to, FeCl.sub.3,
CrCl.sub.3, SnCl.sub.4, or CuCl.sub.2 etc. The hydroxide ion formed
at the cathode combines with sodium ions to form sodium
hydroxide.
[0261] It is to be understood that chloride ions in this
application are for illustration purposes only and that other
equivalent ions such as, but not limited to, sulfate, bromide or
iodide are also well within the scope of the invention and would
result in corresponding metal halide or metal sulfate in the anode
electrolyte. It is also to be understood that MCl.sub.n shown in
the figures illustrated herein, is a mixture of the metal ion in
the lower oxidation state as well as the metal ion in the higher
oxidation state. The integer n in MCl.sub.n merely represents the
metal ion in the lower and higher oxidation state and may be from
1-5 or more depending on the metal ion. For example, in some
embodiments, where copper is the metal ion, the MCl.sub.n may be a
mixture of CuCl and CuCl.sub.2. This mixture of copper ions in the
anode electrolyte may be then contacted with the hydrogen gas,
unsaturated hydrocarbon, and/or saturated hydrocarbon to form
respective products.
[0262] In some embodiments, the cathode used in the electrochemical
systems of the invention, is a hydrogen gas producing cathode that
does not form an alkali. Accordingly, in some embodiments, there
are provided methods that include contacting an anode with a metal
ion in an anode electrolyte in an anode chamber; oxidizing the
metal ion from a lower oxidation state to a higher oxidation state
at the anode; contacting a cathode with a cathode electrolyte in a
cathode chamber; forming hydrogen gas at the cathode. In some
embodiments, there are provided methods that include contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
oxidizing the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a cathode with a cathode
electrolyte in a cathode chamber; forming hydrogen gas at the
cathode; and contacting the anode electrolyte comprising metal ion
in the higher oxidation state with an unsaturated or saturated
hydrocarbon to form halogenated hydrocarbon, or contacting the
anode electrolyte comprising metal ion in the higher oxidation
state with hydrogen gas to form an acid, or combination of both. In
some embodiments, the method further includes separating the
cathode and the anode by at least one ion exchange membrane. In
some embodiments, the ion exchange membrane is a cation exchange
membrane (CEM), an anion exchange membrane (AEM); or combination
thereof. In some embodiments, the above recited method includes an
anode that does not form a gas. In some embodiments, the method
includes an anode that does not use a gas.
[0263] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode is configured to convert
the metal ion from a lower oxidation state to a higher oxidation
state; and a cathode chamber comprising a cathode in contact with a
cathode electrolyte, wherein the cathode is configured to produce
hydrogen gas. In some embodiments, there are provided systems that
include an anode chamber comprising an anode in contact with a
metal ion in an anode electrolyte, wherein the anode is configured
to convert the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising a cathode in
contact with a cathode electrolyte, wherein the cathode is
configured to produce hydrogen gas; and a reactor operably
connected to the anode chamber and configured to contact the anode
electrolyte comprising metal ion in the higher oxidation state with
an unsaturated or saturated hydrocarbon and/or hydrogen gas to form
a halogenated hydrocarbon and acid, respectively. In some
embodiments, the system is configured to not produce a gas at the
anode. In some embodiments, the system is configured to not use a
gas at the anode. In some embodiments, the system further includes
at least one ion exchange membrane separating the cathode and the
anode. In some embodiments, the ion exchange membrane is a cation
exchange membrane (CEM), an anion exchange membrane (AEM); or
combination thereof.
[0264] For example, as illustrated in FIG. 4B, the electrochemical
system 400 includes a cathode in contact with the cathode
electrolyte 401 where the hydrochloric acid delivered to the
cathode electrolyte is transformed to hydrogen gas in the cathode
electrolyte. The system 400 also includes an anode in contact with
the anode electrolyte 402 that converts metal ions in the lower
oxidation state (M.sup.L+) to metal ions in the higher oxidation
states (M.sup.H+). Following are the reactions that take place at
the cathode and the anode:
[0265] 2H.sup.++2e.sup.-.fwdarw.H.sub.2 (cathode)
[0266] M.sup.L+.fwdarw.M.sup.H++xe.sup.- (anode where x=1-3)
[0267] For example, Fe.sup.2+.fwdarw.Fe.sup.3++e.sup.- (anode)
[0268] Cr.sup.2+.fwdarw.Cr.sup.3++e.sup.- (anode)
[0269] Sn.sup.2+.fwdarw.Sn.sup.4++2e.sup.- (anode)
[0270] Cu.sup.+.fwdarw.Cu.sup.2++e.sup.- (anode)
[0271] As illustrated in FIG. 4B, the electrochemical system 400
includes a cathode that forms hydrogen gas at the cathode. The
hydrogen gas may be vented out or captured and stored for
commercial purposes. In some embodiments, the hydrogen released at
the cathode may be subjected to halogenations or sulfonation
(including sulfation) with the metal halide or metal sulfate formed
in the anode electrolyte to form hydrogen chloride, hydrochloric
acid, hydrogen bromide, hydrobromic acid, hydrogen iodide,
hydroiodic acid, or sulfuric acid. Such reaction is described in
detail herein. The M.sup.H+ formed at the anode combines with
chloride ions to form metal chloride in the higher oxidation state
such as, but not limited to, FeCl.sub.3, CrCl.sub.3, SnCl.sub.4, or
CuCl.sub.2 etc. The hydroxide ion formed at the cathode combines
with sodium ions to form sodium hydroxide.
[0272] It is to be understood that one AEM in FIG. 4B is for
illustration purposes only and the system can be designed to have
CEM with HCl delivered into the anode electrolyte and the hydrogen
ions passing through the CEM to the cathode electrolyte. In some
embodiments, the system illustrated in FIG. 4B may contain both AEM
and CEM with the middle chamber containing a chloride salt. It is
also to be understood that MCl.sub.n shown in the figures
illustrated herein, is a mixture of the metal ion in the lower
oxidation state as well as the metal ion in the higher oxidation
state. The integer n in MCl.sub.n merely represents the metal ion
in the lower and higher oxidation state and may be from 1-5 or more
depending on the metal ion. For example, in some embodiments, where
copper is the metal ion, the MCl.sub.n may be a mixture of CuCl and
CuCl.sub.2. This mixture of copper ions in the anode electrolyte
may be then contacted with the hydrogen gas, unsaturated
hydrocarbon, and/or saturated hydrocarbon to form respective
products.
[0273] In some embodiments, the cathode in the electrochemical
systems of the invention may be a gas-diffusion cathode. In some
embodiments, the cathode in the electrochemical systems of the
invention may be a gas-diffusion cathode forming an alkali at the
cathode. In some embodiments, there are provided methods that
include contacting an anode with a metal ion in an anode
electrolyte; oxidizing the metal ion from a lower oxidation state
to a higher oxidation state at the anode; and contacting a
gas-diffusion cathode with a cathode electrolyte. In some
embodiments, the gas-diffusion cathode is an oxygen depolarized
cathode (ODC). In some embodiments, the method includes forming an
alkali at the ODC. In some embodiments, there are provided methods
that include contacting an anode with an anode electrolyte,
oxidizing a metal ion from the lower oxidation state to a higher
oxidation state at the anode; and contacting a cathode with a
cathode electrolyte wherein the cathode is an oxygen depolarizing
cathode that reduces oxygen and water to hydroxide ions. In some
embodiments, there are provided methods that include contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
oxidizing the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a gas-diffusion cathode
with a cathode electrolyte in a cathode chamber; forming an alkali
at the cathode; and contacting the anode electrolyte comprising the
metal ion in the higher oxidation state with an unsaturated and/or
saturated hydrocarbon to form halogenated hydrocarbon, or
contacting the anode electrolyte comprising the metal ion in the
higher oxidation state with hydrogen gas to form an acid, or
combination of both. In some embodiments, the gas-diffusion cathode
does not form a gas. In some embodiments, the method includes an
anode that does not form a gas. In some embodiments, the method
includes an anode that does not use a gas. In some embodiments, the
method further includes separating the cathode and the anode by at
least one ion exchange membrane. In some embodiments, the ion
exchange membrane is a cation exchange membrane (CEM), an anion
exchange membrane (AEM); or combination thereof.
[0274] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode is configured to convert or
oxidize the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising a gas-diffusion
cathode in contact with a cathode electrolyte, wherein the cathode
is configured to produce an alkali. In some embodiments, the
gas-diffusion cathode is an oxygen depolarized cathode (ODC). In
some embodiments, there are provided systems that include an anode
chamber comprising an anode in contact with a metal ion in an anode
electrolyte, wherein the anode is configured to convert the metal
ion from a lower oxidation state to a higher oxidation state; and a
cathode chamber comprising a gas-diffusion cathode in contact with
a cathode electrolyte, wherein the cathode is configured to produce
an alkali; and a reactor operably connected to the anode chamber
and configured to contact the anode electrolyte comprising the
metal ion in the higher oxidation state with an unsaturated and/or
saturated hydrocarbon and/or hydrogen gas to form a halogenated
hydrocarbon and acid, respectively. In some embodiments, the system
is configured to not produce a gas at the gas-diffusion cathode. In
some embodiments, the system is configured to not produce a gas at
the anode. In some embodiments, the system is configured to not use
a gas at the anode. In some embodiments, the system further
includes at least one ion exchange membrane separating the cathode
and the anode. In some embodiments, the ion exchange membrane is a
cation exchange membrane (CEM), an anion exchange membrane (AEM);
or combination thereof.
[0275] As used herein, the "gas-diffusion cathode," or
"gas-diffusion electrode," or other equivalents thereof include any
electrode capable of reacting a gas to form ionic species. In some
embodiments, the gas-diffusion cathode, as used herein, is an
oxygen depolarized cathode (ODC). Such gas-diffusion cathode may be
called gas-diffusion electrode, oxygen consuming cathode, oxygen
reducing cathode, oxygen breathing cathode, oxygen depolarized
cathode, and the like.
[0276] In some embodiments, as illustrated in FIG. 5A, the
combination of the gas diffusion cathode (e.g., ODC) and the anode
in the electrochemical cell may result in the generation of alkali
in the cathode chamber. In some embodiments, the electrochemical
system 500 includes a gas diffusion cathode in contact with a
cathode electrolyte 501 and an anode in contact with an anode
electrolyte 502. The anode and the cathode are separated by an
anion exchange membrane (AEM) and a cation exchange membrane (CEM).
A third electrolyte (e.g., sodium halide or sodium sulfate) is
disposed between the AEM and the CEM. Following are the reactions
that may take place at the anode and the cathode.
[0277] H.sub.2O+1/2O.sub.2+2e.sup.-.fwdarw.2OH.sup.- (cathode)
[0278] M.sup.L+.fwdarw.M.sup.H++xe.sup.- (anode where x=1-3)
[0279] For example, 2Fe.sup.2+.fwdarw.2Fe.sup.3++2e.sup.-
(anode)
[0280] 2Cr.sup.2+.fwdarw.2Cr.sup.3++2e.sup.- (anode)
[0281] Sn.sup.2+.fwdarw.Sn.sup.4++2e.sup.- (anode)
[0282] 2Cu.sup.+.fwdarw.2Cu.sup.2++2e.sup.- (anode)
[0283] The M.sup.H+ formed at the anode combines with chloride ions
to form metal chloride MCl.sub.n such as, but not limited to,
FeCl.sub.3, CrCl.sub.3, SnCl.sub.4, or CuCl.sub.2 etc. The
hydroxide ion formed at the cathode reacts with sodium ions to form
sodium hydroxide. The oxygen at the cathode may be atmospheric air
or any commercial available source of oxygen.
[0284] The methods and systems containing the gas-diffusion cathode
or the ODC, as described herein and illustrated in FIG. 5A, may
result in voltage savings as compared to methods and systems that
include the hydrogen gas producing cathode (as illustrated in FIG.
4A). The voltage savings in-turn may result in less electricity
consumption and less carbon dioxide emission for electricity
generation. This may result in the generation of greener chemicals
such as sodium hydroxide, halogentated hydrocarbons and/or acids,
that are formed by the efficient and energy saving methods and
systems of the invention. In some embodiments, the electrochemical
cell with ODC has a theoretical voltage savings of more than 0.5V,
or more than 1V, or more than 1.5V, or between 0.5-1.5V, as
compared to the electrochemical cell with no ODC or as compared to
the electrochemical cell with hydrogen gas producing cathode. In
some embodiments, this voltage saving is achieved with a cathode
electrolyte pH of between 7-15, or between 7-14, or between 6-12,
or between 7-12, or between 7-10.
[0285] The overall cell potential can be determined through the
combination of Nernst equations for each half cell reaction:
E=E.degree.-RT ln(Q)/nF
where, E.degree. is the standard reduction potential, R is the
universal gas constant (8.314 J/mol K), T is the absolute
temperature, n is the number of electrons involved in the half cell
reaction, F is Faraday's constant (96485 J/V mol), and Q is the
reaction quotient so that:
E.sub.total=E.sub.anode-E.sub.cathode
[0286] When metal in the lower oxidation state is oxidized to metal
in the higher oxidation state at the anode as follows:
[0287] Cu.sup.+.fwdarw.Cu.sup.2++2e.sup.-
E.sub.anode based on varying concentration of copper II species may
be between 0.159-0.75V.
[0288] When water is reduced to hydroxide ions and hydrogen gas at
the cathode (as illustrated in FIG. 4A) as follows:
2H.sub.2O+2e.sup.-.dbd.H.sub.2+2OH.sup.-, [0289]
E.sub.cathode=-0.059 pH.sub.c, where pH.sub.c is the pH of the
cathode electrolyte=14 [0290] E.sub.cathode=-0.83
[0291] E.sub.total then is between 0.989 to 1.53, depending on the
concentration of copper ions in the anode electrolyte.
[0292] When water is reduced to hydroxide ions at ODC (as
illustrated in FIG. 5A) as follows:
2H.sub.2O+O.sub.2+4e.sup.-.fwdarw.4OH.sup.-
[0293] E.sub.cathode=1.224-0.059 pH.sub.c, where pH.sub.c=14
[0294] E.sub.cathode=0.4V
[0295] E.sub.total then is between -0.241 to 0.3V depending on the
concentration of copper ions in the anode electrolyte.
[0296] Therefore, the use of ODC in the cathode chamber brings the
theoretical voltage savings in the cathode chamber or the
theoretical voltage savings in the cell of about 1.5V or between
0.5-2V or between 0.5-1.5V or between 1-1.5V, as compared to the
electrochemical cell with no ODC or as compared to the
electrochemical cell with hydrogen gas producing cathode.
[0297] Accordingly, in some embodiments, there are provided methods
that include contacting an anode with a metal ion in an anode
electrolyte; contacting an oxygen depolarizing cathode with a
cathode electrolyte; applying a voltage to the anode and the
cathode; forming an alkali at the cathode; converting the metal ion
from a lower oxidation state to a higher oxidation state at the
anode; and saving a voltage of more than 0.5V or between 0.5-1.5V
as compared to the hydrogen gas producing cathode or as compared to
the cell with no ODC. In some embodiments, there are provided
systems that include an anode chamber comprising an anode in
contact with a metal ion in an anode electrolyte, wherein the anode
is configured to convert the metal ion from a lower oxidation state
to a higher oxidation state; and a cathode chamber comprising an
oxygen depolarizing cathode in contact with a cathode electrolyte,
wherein the cathode is configured to produce an alkali, wherein the
system provides a voltage savings of more than 0.5V or between
0.5-1.5V as compared to the system with the hydrogen gas producing
cathode or as compared to the system with no ODC. In some
embodiments, the voltage savings is a theoretical voltage saving
which may change depending on the ohmic resistances in the
cell.
[0298] While the methods and systems containing the gas-diffusion
cathode or the ODC result in voltage savings as compared to methods
and systems containing the hydrogen gas producing cathode, both the
systems i.e. systems containing the ODC and the systems containing
hydrogen gas producing cathode of the invention, show significant
voltage savings as compared to chlor-alkali system conventionally
known in the art. The voltage savings in-turn may result in less
electricity consumption and less carbon dioxide emission for
electricity generation. This may result in the generation of
greener chemicals such as sodium hydroxide, halogentated
hydrocarbons and/or acids, that are formed by the efficient and
energy saving methods and systems of the invention. For example,
the voltage savings is beneficial in production of the halogenated
hydrocarbons, such as EDC, which is typically formed by reacting
ethylene with chlorine gas generated by the high voltage consuming
chlor-alkali process. In some embodiments, the electrochemical
system of the invention (2 or 3-compartment cells with hydrogen gas
producing cathode or ODC) has a theoretical voltage savings of more
than 0.5V, or more than 1V, or more than 1.5V, or between 0.5-3V,
as compared to chlor-alkali process. In some embodiments, this
voltage saving is achieved with a cathode electrolyte pH of between
7-15, or between 7-14, or between 6-12, or between 7-12, or between
7-10.
[0299] For example, theoretical E.sub.anode in the chlor-alkali
process is about 1.36V undergoing the reaction as follows:
2Cl.sup.-.fwdarw.Cl.sub.2+2e.sup.-,
[0300] Theoretical E.sub.cathode in the chlor-alkali process is
about -0.83V (at pH>14) undergoing the reaction as follows:
2H.sub.2O+2e.sup.-.dbd.H.sub.2.+-.2OH.sup.-
[0301] Theoretical E.sub.total for the chlor-alkali process then is
2.19V. Theoretical E.sub.total for the hydrogen gas producing
cathode in the system of the invention is between 0.989 to 1.53V
and E.sub.total for ODC in the system of the invention then is
between -0.241 to 0.3V, depending on the concentration of copper
ions in the anode electrolyte. Therefore, the electrochemical
systems of the invention bring the theoretical voltage savings in
the cathode chamber or the theoretical voltage savings in the cell
of greater than 3V or greater than 2V or between 0.5-2.5V or
between 0.5-2.0V or between 0.5-1.5V or between 0.5-1.0V or between
1-1.5V or between 1-2V or between 1-2.5V or between 1.5-2.5V, as
compared to the chlor-alkali system.
[0302] In some embodiments, the electrochemical cell may be
conditioned with a first electrolyte and may be operated with a
second electrolyte. For example, in some embodiments, the
electrochemical cell and the AEM, CEM or combination thereof are
conditioned with sodium sulfate as the electrolyte and after the
stabilization of the voltage with sodium sulfate, the cell may be
operated with sodium chloride as the electrolyte. An illustrative
example of such stabilization of the electrochemical cell is
described in Example 13 herein. Accordingly, in some embodiments,
there are provided methods that include contacting an anode with a
first anode electrolyte in an anode chamber; contacting a cathode
with a cathode electrolyte in a cathode chamber; separating the
cathode and the anode by at least one ion exchange membrane;
conditioning the ion exchange membrane with the first anode
electrolyte in the anode chamber; contacting the anode with a
second anode electrolyte comprising metal ion; oxidizing the metal
ion from a lower oxidation state to a higher oxidation state at the
anode; and forming an alkali, water, and/or hydrogen gas at the
cathode. In some embodiments, the first anode electrolyte is sodium
sulfate and the second anode electrolyte is sodium chloride. In
some embodiments, the method further comprises contacting the
second anode electrolyte comprising metal ion in the higher
oxidation state with an unsaturated and/or saturated hydrocarbon to
form halogenated hydrocarbon, or contacting the second anode
electrolyte comprising metal ion in the higher oxidation state with
hydrogen gas to form an acid, or combination of both. In some
embodiments, the ion exchange membrane is a cation exchange
membrane (CEM), an anion exchange membrane (AEM); or combination
thereof.
[0303] In some embodiments, the cathode in the electrochemical
systems of the invention may be a gas-diffusion cathode that reacts
HCl and oxygen gas to form water. In some embodiments, there are
provided methods that include contacting an anode with a metal ion
in an anode electrolyte; oxidizing the metal ion from a lower
oxidation state to a higher oxidation state at the anode; and
contacting a gas-diffusion cathode with a cathode electrolyte. In
some embodiments, the gas-diffusion cathode is an oxygen
depolarized cathode (ODC). In some embodiments, the method includes
reacting HCl and oxygen gas to form water at the ODC. In some
embodiments, there are provided methods that include contacting an
anode with an anode electrolyte, oxidizing a metal ion from the
lower oxidation state to a higher oxidation state at the anode; and
contacting a cathode with a cathode electrolyte wherein the cathode
is an oxygen depolarizing cathode that reacts oxygen and HCl to
form water. In some embodiments, there are provided methods that
include contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; oxidizing the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a gas-diffusion cathode with a cathode electrolyte in a
cathode chamber; forming water at the cathode from HCl and oxygen
gas; and contacting the anode electrolyte comprising the metal ion
in the higher oxidation state with an unsaturated and/or saturated
hydrocarbon to form halogenated hydrocarbon, or contacting the
anode electrolyte comprising the metal ion in the higher oxidation
state with hydrogen gas to form an acid, or combination of both. In
some embodiments, the gas-diffusion cathode does not form a gas. In
some embodiments, the method includes an anode that does not form a
gas. In some embodiments, the method includes an anode that does
not use a gas. In some embodiments, the method further includes
separating the cathode and the anode by at least one ion exchange
membrane. In some embodiments, the ion exchange membrane is a
cation exchange membrane (CEM), an anion exchange membrane (AEM);
or combination thereof.
[0304] In some embodiments, there are provided systems that include
an anode chamber comprising an anode in contact with a metal ion in
an anode electrolyte, wherein the anode is configured to convert or
oxidize the metal ion from a lower oxidation state to a higher
oxidation state; and a cathode chamber comprising a gas-diffusion
cathode in contact with a cathode electrolyte, wherein the cathode
is configured to produce water from HCl. In some embodiments, the
gas-diffusion cathode is an oxygen depolarized cathode (ODC). In
some embodiments, there are provided systems that include an anode
chamber comprising an anode in contact with a metal ion in an anode
electrolyte, wherein the anode is configured to convert the metal
ion from a lower oxidation state to a higher oxidation state; and a
cathode chamber comprising a gas-diffusion cathode in contact with
a cathode electrolyte, wherein the cathode is configured to produce
water from HCl; and a reactor operably connected to the anode
chamber and configured to contact the anode electrolyte comprising
the metal ion in the higher oxidation state with an unsaturated
and/or saturated hydrocarbon and/or hydrogen gas to form a
halogenated hydrocarbon and acid, respectively. In some
embodiments, the system is configured to not produce a gas at the
gas-diffusion cathode. In some embodiments, the system is
configured to not produce a gas at the anode. In some embodiments,
the system is configured to not use a gas at the anode. In some
embodiments, the system further includes at least one ion exchange
membrane separating the cathode and the anode. In some embodiments,
the ion exchange membrane is a cation exchange membrane (CEM), an
anion exchange membrane (AEM); or combination thereof.
[0305] In some embodiments, as illustrated in FIG. 5B, the
combination of the gas diffusion cathode (e.g., ODC) and the anode
in the electrochemical cell may result in the generation of water
in the cathode chamber. In some embodiments, the electrochemical
system 500 includes a gas diffusion cathode in contact with a
cathode electrolyte 501 and an anode in contact with an anode
electrolyte 502. Following are the reactions that may take place at
the anode and the cathode.
[0306] 2H.sup.++1/2O.sub.2+2e.sup.-.fwdarw.H.sub.2O (cathode)
[0307] M.sup.L+.varies.M.sup.H++xe.sup.- (anode where x=1-3)
[0308] For example, 2Fe.sup.2+.fwdarw.2Fe.sup.3++2e.sup.-
(anode)
[0309] 2Cr.sup.2+.fwdarw.2Cr.sup.3++2e.sup.- (anode)
[0310] Sn.sup.2+.fwdarw.Sn.sup.4++2e.sup.- (anode)
[0311] 2Cu.sup.+.fwdarw.2Cu.sup.2++2e.sup.- (anode)
[0312] The M.sup.H+ formed at the anode combines with chloride ions
to form metal chloride MCl.sub.n such as, but not limited to,
FeCl.sub.3, CrCl.sub.3, SnCl.sub.4, or CuCl.sub.2 etc. The oxygen
at the cathode may be atmospheric air or any commercial available
source of oxygen. It is to be understood that one AEM in FIG. 5B is
for illustration purposes only and the system can be designed to
have CEM with HCl delivered into the anode electrolyte and the
hydrogen ions passing through the CEM to the cathode electrolyte.
In some embodiments, the system illustrated in FIG. 5B may contain
both AEM and CEM with the middle chamber containing a chloride
salt.
[0313] In some embodiments, the electrochemical systems of the
invention may be combined with other electrochemical cells for an
efficient and low energy intensive system. For example, in some
embodiments, as illustrated in FIG. 5C, the electrochemical system
400 of FIG. 4B may be combined with another electrochemical cell
such that the hydrochloric acid formed in the other electrochemical
cell is administered to the cathode electrolyte of the system 400.
The electrochemical system 400 may be replaced with system 100A
(FIG. 1A), 100B (FIG. 1B), 200 (FIG. 2), 400 (FIG. 4A), 500 (FIGS.
5A and 5B), except that the cathode compartment is modified to
receive HCl from another electrochemical cell and oxidize it to
form hydrogen gas. The chloride ions migrate from the cathode
electrolyte to anode electrolyte through the AEM. This may result
in an overall improvement in the voltage of the system, e.g., the
theoretical cell voltage of the system may be between 0.1-0.7V. In
some embodiments, when the cathode is an ODC, the theoretical cell
voltage may be between -0.5 to -1V. The electrochemical cells
producing HCl in the anode electrolyte have been described in U.S.
patent application Ser. No. 12/503,557, filed Jul. 15, 2009, which
is incorporated herein by reference in its entirety. Other sources
of HCl are well known in the art. An example of HCl source from VCM
production process and its integration into the electrochemical
system of the invention, is illustrated in FIG. 8B below.
[0314] In some embodiments of the methods and systems described
herein, a size exclusion membrane (SEM) is used in conjunction with
or in place of anion exchange membrane (AEM). In some embodiments,
the AEM is surface coated with a layer of SEM. In some embodiments,
the SEM is bonded or pressed against the AEM. The use of SEM with
or in place of AEM can prevent migration of the metal ion or ligand
attached metal ion from the anolyte to the catholyte owing to the
large size of the metal ion alone or attached to the ligand. This
can further prevent fouling of CEM or contamination of the
catholyte with the metal ion. It is to be understood that this use
of SEM in combination with or in place of AEM will still facilitate
migration of chloride ions from the third electrolyte into the
anolyte. In some embodiments, there are provided methods that
include contacting an anode with an anode electrolyte; oxidizing a
metal ion from the lower oxidation state to a higher oxidation
state at the anode; contacting a cathode with a cathode
electrolyte; and preventing migration of the metal ions from the
anode electrolyte to the cathode electrolyte by using a size
exclusion membrane. In some embodiments, this method further
includes a cathode that produces alkali in the cathode electrolyte,
or an oxygen depolarized cathode that produces alkali in the
cathode electrolyte or an oxygen depolarized cathode that produces
water in the cathode electrolyte or a cathode that produces
hydrogen gas. In some embodiments, this method further includes
contacting the anode electrolyte comprising the metal ion in the
higher oxidation state with an unsaturated or saturated hydrocarbon
to form halogenated hydrocarbon, or contacting the anode
electrolyte comprising the metal ion in the higher oxidation state
with hydrogen gas to form an acid, or combination of both. In some
embodiments, the unsaturated hydrocarbon in such methods is
ethylene. In some embodiments, the metal ion in such methods is
copper chloride. In some embodiments, the unsaturated hydrocarbon
in such methods is ethylene and the metal ion is copper chloride.
An example of halogenated hydrocarbon that can be formed from
ethylene is ethylene dichloride, EDC.
[0315] In some embodiments, there are provided systems that include
an anode in contact with an anode electrolyte and configured to
oxidize a metal ion from the lower oxidation state to a higher
oxidation state; a cathode in contact with a cathode electrolyte;
and a size exclusion membrane disposed between the anode and the
cathode and configured to prevent migration of the metal ions from
the anode electrolyte to the cathode electrolyte. In some
embodiments, this system further includes a cathode that is
configured to produce alkali in the cathode electrolyte or produce
water in the cathode electrolyte or produce hydrogen gas. In some
embodiments, this system further includes an oxygen depolarized
cathode that is configured to produce alkali and/or water in the
cathode electrolyte. In some embodiments, this system further
includes a hydrogen gas producing cathode. In some embodiments,
this system further includes a reactor operably connected to the
anode chamber and configured to contact the anode electrolyte
comprising the metal ion in the higher oxidation state with an
unsaturated or saturated hydrocarbon to form halogenated
hydrocarbon, or to contact the anode electrolyte comprising the
metal ion in the higher oxidation state with hydrogen gas to form
an acid, or combination of both. In some embodiments, the
unsaturated hydrocarbon in such systems is ethylene. In some
embodiments, the metal ion in such systems is copper chloride. In
some embodiments, the unsaturated hydrocarbon in such systems is
ethylene and the metal ion is copper chloride. An example of
halogenated hydrocarbon that can be formed from ethylene is
EDC.
[0316] In some embodiments, the size exclusion membrane as defined
herein above and herein, fully prevents the migration of the metal
ion to the cathode chamber or the middle chamber with the third
electrolyte or reduces the migration by 100%; or by 99%; or by 95%
or by 75%; or by 50%; or by 25%; or between 25-50%; or between
50-75%; or between 50-95%.
[0317] In some embodiments, the AEM used in the methods and systems
of the invention, is resistant to the organic compounds (such as
ligands or hydrocarbons) such that AEM does not interact with the
organics and/or the AEM does not react or absorb metal ions. This
can be achieved, for example only, by using a polymer that does not
contain a free radical or anion available for reaction with
organics or with metal ions. For example only, a fully quarternized
amine containing polymer may be used as an AEM. Other examples of
AEM have been described herein.
[0318] In some embodiments, the metal formed with a higher
oxidation state in the anode electrolyte is subjected to reactions
that may result in corresponding oxidized products (halogenated
hydrocarbon and/or acid) as well as the metal in the reduced lower
oxidation state. The metal ion in the lower oxidation state may
then be re-circulated back to the electrochemical system for the
generation of the metal ion in the higher oxidation state. Such
reactions to regenerate the metal ion in the lower oxidation state
from the metal ion in the higher oxidation state, include, but are
not limited to, reactions with hydrogen gas or hydrocarbons as
described herein.
Reaction with Hydrogen Gas, Unsaturated Hydrocarbon, and Saturated
Hydrocarbon
[0319] In some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting or oxidizing the metal ion from a lower
oxidation state to a higher oxidation state at the anode; and
treating the metal ion in the higher oxidation state with hydrogen
gas. In some embodiments of the method, the method includes
contacting a cathode with a cathode electrolyte and forming an
alkali in the cathode electrolyte. In some embodiments of the
method, the method includes contacting a cathode with a cathode
electrolyte and forming an alkali and/or hydrogen gas at the
cathode. In some embodiments of the method, the method includes
contacting a cathode with a cathode electrolyte and forming an
alkali, water, and/or hydrogen gas at the cathode. In some
embodiments of the method, the method includes contacting a
gas-diffusion cathode with a cathode electrolyte and forming an
alkali at the cathode. In some embodiments, there are provided
methods that include contacting an anode with a metal ion in an
anode electrolyte in an anode chamber; converting the metal ion
from a lower oxidation state to a higher oxidation state at the
anode; contacting a cathode with a cathode electrolyte; forming an
alkali, water or hydrogen gas at the cathode; and treating the
metal ion in the higher oxidation state in the anode electrolyte
with hydrogen gas from the cathode. In some embodiments, there are
provided methods that include contacting an anode with a metal ion
in an anode electrolyte in an anode chamber; converting the metal
ion from a lower oxidation state to a higher oxidation state at the
anode; contacting an oxygen depolarized cathode with a cathode
electrolyte; forming an alkali or water at the cathode; and
treating the metal ion in the higher oxidation state in the anode
electrolyte with hydrogen gas. In some embodiments, there are
provided methods that include contacting an anode with a metal ion
in an anode electrolyte in an anode chamber; converting the metal
ion from a lower oxidation state to a higher oxidation state at the
anode; contacting a cathode with a cathode electrolyte; forming
water or hydrogen gas at the cathode; and treating the metal ion in
the higher oxidation state in the anode electrolyte with hydrogen
gas. In some embodiments, the treatment of the hydrogen gas with
the metal ion in the higher oxidation state may be inside the
cathode chamber or outside the cathode chamber. In some
embodiments, the above recited methods include forming hydrogen
chloride, hydrochloric acid, hydrogen bromide, hydrobromic acid,
hydrogen iodide, hydroiodic acid and/or sulfuric acid by treating
the metal ion in the higher oxidation state with the hydrogen gas.
In some embodiments, the treatment of the metal ion in the higher
oxidation state with the hydrogen gas results in forming hydrogen
chloride, hydrochloric acid, hydrogen bromide, hydrobromic acid,
hydrogen iodide, hydroiodic acid, and/or sulfuric acid and the
metal ion in the lower oxidation state. In some embodiments, the
metal ion in the lower oxidation state is re-circulated back to the
anode chamber. In some embodiments, the mixture of the metal ion in
the lower oxidation state and the acid is subjected to acid
retardation techniques to separate the metal ion in the lower
oxidation state from the acid before the metal ion in the lower
oxidation state is re-circulated back to the anode chamber.
[0320] In some embodiments of the above recited methods, the method
does not produce chlorine gas at the anode.
[0321] In some embodiments, there are provided systems that include
an anode chamber including an anode in contact with a metal ion in
an anode electrolyte wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state;
and a reactor operably connected to the anode chamber and
configured to react the anode electrolyte comprising the metal ion
in the higher oxidation state with hydrogen gas. In some
embodiments of the systems, the system includes a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form an alkali in the cathode electrolyte. In some
embodiments of the systems, the system includes a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form hydrogen gas in the cathode electrolyte. In
some embodiments of the systems, the system includes a cathode
chamber including a cathode with a cathode electrolyte wherein the
cathode is configured to form an alkali and hydrogen gas in the
cathode electrolyte. In some embodiments of the systems, the system
includes a gas-diffusion cathode with a cathode electrolyte wherein
the cathode is configured to form an alkali in the cathode
electrolyte. In some embodiments of the systems, the system
includes a gas-diffusion cathode with a cathode electrolyte wherein
the cathode is configured to form water in the cathode electrolyte.
In some embodiments, there are provided systems that include an
anode chamber including an anode with a metal ion in an anode
electrolyte wherein the anode is configured to convert the metal
ion from a lower oxidation state to a higher oxidation state in the
anode chamber; a cathode chamber including a cathode with a cathode
electrolyte wherein the cathode is configured to form an alkali
and/or hydrogen gas in the cathode electrolyte; and a reactor
operably connected to the anode chamber and configured to react the
anode electrolyte comprising the metal ion in the higher oxidation
state with the hydrogen gas from the cathode. In some embodiments,
the reactor is operably connected to the anode chamber and
configured to react the anode electrolyte comprising the metal ion
in the higher oxidation state with the hydrogen gas from the
cathode of the same electrochemical cell or with the external
source of hydrogen gas. In some embodiments, the treatment of the
hydrogen gas with the metal ion in the higher oxidation state may
be inside the cathode chamber or outside the cathode chamber. In
some embodiments, the above recited systems include forming
hydrogen chloride, hydrochloric acid, hydrogen bromide, hydrobromic
acid, hydrogen iodide, hydroiodic acid, and/or sulfuric acid by
reacting or treating the metal ion in the higher oxidation state
with the hydrogen gas. In some embodiments, the treatment of the
metal ion in the higher oxidation state with the hydrogen gas
results in forming hydrogen chloride, hydrochloric acid, hydrogen
bromide, hydrobromic acid, hydrogen iodide, hydroiodic acid, and/or
sulfuric acid and the metal ion in the lower oxidation state. In
some embodiments, the system is configured to form the metal ion in
the lower oxidation state from the metal ion in the higher
oxidation state with the hydrogen gas and re-circulate the metal
ion in the lower oxidation state back to the anode chamber. In some
embodiments, the system is configured to separate the metal ion in
the lower oxidation state from the acid using acid retardation
techniques such as, but not limited to, ion exchange resin, size
exclusion membranes, and acid dialysis, etc.
[0322] In some embodiments of the above recited systems, the anode
in the system is configured to not produce chlorine gas.
[0323] In some embodiments, the metal formed with a higher
oxidation state in the anode electrolyte of the electrochemical
systems of FIGS. 1A, 1B, 2, 3A, 3B, 4A, 4B, 5A and 5B may be
reacted with hydrogen gas to from corresponding products based on
the anion attached to the metal. For example, the metal chloride,
metal bromide, metal iodide, or metal sulfate may result in
corresponding hydrogen chloride, hydrochloric acid, hydrogen
bromide, hydrobromic acid, hydrogen iodide, hydroiodic acid, or
sulfuric acid, respectively, after reacting the hydrogen gas with
the metal halide or metal sulfate. In some embodiments, the
hydrogen gas is from an external source. In some embodiments, such
as illustrated in FIG. 4A or 4B, the hydrogen gas reacted with the
metal halide or metal sulfate, is the hydrogen gas formed at the
cathode. In some embodiments, the hydrogen gas is obtained from a
combination of the external source and the hydrogen gas formed at
the cathode. In some embodiments, the reaction of metal halide or
metal sulfate with the hydrogen gas results in the generation of
the above described products as well as the metal halide or metal
sulfate in the lower oxidation state. The metal ion in the lower
oxidation state may then be re-circulated back to the
electrochemical system for the generation of the metal ion in the
higher oxidation state.
[0324] An example of the electrochemical system of FIG. 5A is as
illustrated in FIG. 6. It is to be understood that the system 600
of FIG. 6 is for illustration purposes only and other metal ions
with different oxidations states (e.g., chromium, tin etc.) and
other electrochemical systems forming products other than alkali
such as, water (as in FIG. 5B) or hydrogen gas (as in FIG. 4A or
4B), in the cathode chamber, are equally applicable to the system.
In some embodiments, as illustrated in FIG. 6, the electrochemical
system 600 includes an oxygen depolarized cathode that produces
hydroxide ions from water and oxygen. The system 600 also includes
an anode that converts metal ions from 2+ oxidation state to 3+
oxidation state (or from 2+ oxidation state to 4+ oxidation state,
such as Sn, etc.). The M.sup.3+ ions combine with chloride ions to
form MCl.sub.3. The metal chloride MCl.sub.3 is then reacted with
hydrogen gas to undergo reduction of the metal ion to lower
oxidation state to form MCl.sub.2. The MCl.sub.2 is then
re-circulated back to the anode chamber for conversion to
MCl.sub.3. Hydrochloric acid is generated in the process which may
be used for commercial purposes or may be utilized in other
processes as described herein. In some embodiments, the HCl
produced by this method can be used for the dissolution of minerals
to generate divalent cations that can be used in carbonate
precipitation processes, as described herein. In some embodiments,
the metal halide or metal sulfate in FIG. 6 may be reacted with the
unsaturated or saturated hydrocarbon to form halohydrocarbon or
sulfohydrocarbon, as described herein (not shown in the figures).
In some embodiments, the cathode is not a gas-diffusion cathode but
is a cathode as described in FIG. 4A or 4B. In some embodiments,
the system 600 may be applied to any electrochemical system that
produces alkali.
[0325] Some examples of the reactors that carry out the reaction of
the metal compound with the hydrogen gas are provided herein. As an
example, a reactor such as a reaction tower for the reaction of
metal ion in the higher oxidation state (formed as shown in the
figures) with hydrogen gas is illustrated in FIG. 7A. In some
embodiments, as illustrated in FIG. 7A, the anolyte is passed
through the reaction tower. The gas containing hydrogen is also
delivered to the reaction tower. The excess of hydrogen gas may
vent from the reaction tower which may be collected and transferred
back to the reaction tower. Inside the reaction tower, the anolyte
containing metal ions in higher oxidation state (illustrated as
FeCl.sub.3) may react with the hydrogen gas to form HCl and metal
ions in lower oxidation state, i.e., reduced form illustrated as
FeCl.sub.2. The reaction tower may optionally contain activated
charcoal or carbon or alternatively, the activated carbon may be
present outside the reaction tower. The reaction of the metal ion
with hydrogen gas may take place on the activated carbon from which
the reduced anolyte may be regenerated or the activated carbon may
simply act as a filter for removing impurities from the gases. The
reduced anolyte containing HCl and the metal ions in lower
oxidation state may be subjected to acid recovery using separation
techniques or acid retardation techniques known in the art
including, but not limited to, ion exchange resin, size exclusion
membranes, and acid dialysis, etc. to separate HCl from the
anolyte. In some embodiments, the ligands, described herein, may
facilitate the separation of the metal ion from the acid solution
due to the large size of the ligand attached to the metal ion. The
anolyte containing the metal ion in the lower oxidation state may
be re-circulated back to the electrochemical cell and HCl may be
collected.
[0326] As another example of the reactor, the reaction of metal ion
in the higher oxidation state (formed as shown in the figures) with
hydrogen gas is also illustrated in FIG. 7B. As illustrated in FIG.
7B, the anolyte from the anode chamber containing the metal ions in
the higher oxidation state, such as, but not limited to, Fe.sup.3+,
Sn.sup.4+, Cr.sup.3+, etc. may be used to react with hydrogen gas
to form HCl or may be used to scrub the SO.sub.2 containing gas to
form clean gas or sulfuric acid. In some embodiments, it is
contemplated that NOx gases may be reacted with the metal ions in
the higher oxidation state to form nitric acid. In some
embodiments, as illustrated in FIG. 7B, the anolyte is passed
through a reaction tower. The gas containing hydrogen, SO.sub.2,
and/or NOx is also delivered to the reaction tower. The excess of
hydrogen gas may vent from the reaction tower which may be
collected and transferred back to the reaction tower. The excess of
SO.sub.2 may be passed through a scrubber before releasing the
cleaner gas to the atmosphere. Inside the reaction tower, the
anolyte containing metal ions in higher oxidation state may react
with the hydrogen gas and/or SO.sub.2 to form HCl and/or
H.sub.2SO.sub.4 and metal ions in lower oxidation state, i.e.,
reduced form. The reaction tower may optionally contain activated
charcoal or carbon or alternatively, the activated carbon may be
present outside the reaction tower. The reaction of the metal ion
with hydrogen gas or SO.sub.2 gas may take place on the activated
carbon from which the reduced anolyte may be regenerated or the
activated carbon may simply act as a filter for removing impurities
from the gases. The reduced anolyte containing HCl and/or
H.sub.2SO.sub.4 and the metal ions in lower oxidation state may be
subjected to acid recovery using separation techniques known in the
art including, but not limited to, ion exchange resin, size
exclusion membranes, and acid dialysis, etc. to separate HCl and/or
H.sub.2SO.sub.4 from the anolyte. In some embodiments, the ligands,
described herein, may facilitate the separation of the metal ion
from the acid solution due to the large size of the ligand attached
to the metal ion. The anolyte containing the metal ion in the lower
oxidation state may be re-circulated back to the electrochemical
cell and HCl and/or H.sub.2SO.sub.4 may be collected. In some
embodiments, the reaction inside the reaction tower may take place
from 1-10 hr at a temperature of 50-100.degree. C.
[0327] An example of an ion exchange resin to separate out the HCl
from the metal containing anolyte is as illustrated in FIG. 7C. As
illustrated in FIG. 7C, the separation process may include a
preferential adsorption/absorption of a mineral acid to an anion
exchange resin. In the first step, the anolyte containing HCl
and/or H.sub.2SO.sub.4 is passed through the ion exchange resin
which adsorbs HCl and/or H.sub.2SO.sub.4 and then separates out the
anolyte. The HCl and/or H.sub.2SO.sub.4 can be regenerated back
from the resin by washing the resin with water. Diffusion dialysis
can be another method for separating acid from the anolyte. In some
embodiments, the ligands described herein, may facilitate the
separation of the metal ion from the acid solution due to the large
size of the ligand attached to the metal ion.
[0328] In some embodiments, the hydrochloric acid generated in the
process is partially or fully used to dissolve scrap iron to form
FeCl.sub.2 and hydrogen gas. The FeCl.sub.2 generated in the
process may be re-circulated back to the anode chamber for
conversion to FeCl.sub.3. In some embodiments, the hydrogen gas may
be used in the hydrogen fuel cell. The fuel cell in turn can be
used to generate electricity to power the electrochemical described
herein. In some embodiments, the hydrogen gas is transferred to the
electrochemical systems described in U.S. Provisional Application
No. 61/477,097, which is incorporated herein by reference in its
entirety.
[0329] In some embodiments, the hydrochloric acid with or without
the metal ion in the lower oxidation state is subjected to another
electrochemical process to generate hydrogen gas and the metal ion
in the higher oxidation state. Such a system is as illustrated in
FIG. 11.
[0330] In some embodiments, the hydrochloric acid generated in the
process is used to generate ethylene dichloride as illustrated
below:
[0331] 2CuCl (aq)+2HCl (aq)+1/2O.sub.2 (g).fwdarw.2CuCl.sub.2
(aq)+H.sub.2O (l)
[0332] C.sub.2H.sub.4 (g)+2CuCl.sub.2 (aq).fwdarw.2CuCl
(aq)+C.sub.2H.sub.4Cl.sub.2 (l)
[0333] In some embodiments, the metal formed with a higher
oxidation state in the anode electrolyte of the electrochemical
systems of FIGS. 1A, 1B, 2, 3A, 3B, 4A, 4B, 5A, 5B, and 5C may be
reacted with unsaturated hydrocarbons to from corresponding
halohydrocarbons or sulfohydrocarbons based on the anion attached
to the metal. For example, the metal chloride, metal bromide, metal
iodide, or metal sulfate etc. may result in corresponding
chlorohydrocarbons, bromohydrocarbons, iodohydrocarbons, or
sulfohydrocarbons, after the reaction of the unsaturated
hydrocarbons with the metal halide or metal sulfate. In some
embodiments, the reaction of metal halide or metal sulfate with the
unsaturated hydrocarbons results in the generation of the above
described products as well as the metal halide or metal sulfate in
the lower oxidation state. The metal ion in the lower oxidation
state may then be re-circulated back to the electrochemical system
for the generation of the metal ion in the higher oxidation
state.
[0334] The "unsaturated hydrocarbon" as used herein, includes a
hydrocarbon with unsaturated carbon or hydrocarbon with at least
one double and/or at least one triple bond between adjacent carbon
atoms. The unsaturated hydrocarbon may be linear, branched, or
cyclic (aromatic or non-aromatic). For example, the hydrocarbon may
be olefinic, acetylenic, non-aromatic such as cyclohexene, aromatic
group or a substituted unsaturated hydrocarbon such as, but not
limited to, halogenated unsaturated hydrocarbon. The hydrocarbons
with at least one double bond may be called olefins or alkenes and
may have a general formula of an unsubstituted alkene as
C.sub.nH.sub.2n where n is 2-20 or 2-10 or 2-8, or 2-5. In some
embodiments, one or more hydrogens on the alkene may be further
substituted with other functional groups such as but not limited
to, halogen (including chloro, bromo, iodo, and fluoro), carboxylic
acid (--COOH), hydroxyl (--OH), amines, etc. The unsaturated
hydrocarbons include all the isomeric forms of unsaturation, such
as, but not limited to, cis and trans isomers, E and Z isomers,
positional isomers etc.
[0335] In some embodiments, the unsaturated hydrocarbon in the
methods and systems provided herein, is of formula I which after
halogenation or sulfonation (including sulfation) results in the
compound of formula II:
##STR00019##
[0336] wherein, n is 2-10; m is 0-5; and q is 1-5;
[0337] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0338] X is a halogen selected from fluoro, chloro, bromo, and
iodo; --SO.sub.3H; or --OSO.sub.2OH.
[0339] It is to be understood that R substitutent(s) can be on one
carbon atom or on more than 1 carbon atom depending on the number
of R and carbon atoms. For example only, when n is 3 and m is 2,
the substituents R can be on the same carbon atom or on two
different carbon atoms.
[0340] In some embodiments, the unsaturated hydrocarbon in the
methods and systems provided herein, is of formula I which after
halogenation results in the compound of formula II, wherein, n is
2-10; m is 0-5; and q is 1-5; R is independently selected from
hydrogen, halogen, --COOR', --OH, and --NR' (R''), where R' and R''
are independently selected from hydrogen, alkyl, and substituted
alkyl; and X is a halogen selected from chloro, bromo, and
iodo.
[0341] In some embodiments, the unsaturated hydrocarbon in the
methods and systems provided herein, is of formula I which after
halogenation results in the compound of formula II, wherein, n is
2-5; m is 0-3; and q is 1-4; R is independently selected from
hydrogen, halogen, --COOR', --OH, and --NR' (R''), where R' and R''
are independently selected from hydrogen and alkyl; and X is a
halogen selected from chloro and bromo.
[0342] In some embodiments, the unsaturated hydrocarbon in the
methods and systems provided herein, is of formula I which after
halogenation results in the compound of formula II, wherein, n is
2-5; m is 0-3; and q is 1-4; R is independently selected from
hydrogen, halogen, and --OH, and X is a halogen selected from
chloro and bromo.
[0343] It is to be understood that when m is more than 1, the
substituents R can be on the same carbon atom or on a different
carbon atoms. Similarly, it is to be understood that when q is more
than 1, the substituents X can be on the same carbon atom or on
different carbon atoms.
[0344] In some embodiments for the above described embodiments of
formula I, m is 0 and q is 1-2. In such embodiments, X is
chloro.
[0345] Examples of substituted or unsubstituted alkenes, including
formula I, include, but not limited to, ethylene, chloro ethylene,
bromo ethylene, iodo ethylene, propylene, chloro propylene,
hydroxyl propylene, 1-butylene, 2-butylene (cis or trans),
isobutylene, 1,3-butadiene, pentylene, hexene, cyclopropylene,
cyclobutylene, cyclohexene, etc. The hydrocarbons with at least one
triple bond maybe called alkynes and may have a general formula of
an unsubstituted alkyne as C.sub.nH.sub.2n-2 where n is 2-10 or
2-8, or 2-5. In some embodiments, one or more hydrogens on the
alkyne may be further substituted with other functional groups such
as but not limited to, halogen, carboxylic acid, hydroxyl, etc.
[0346] In some embodiments, the unsaturated hydrocarbon in the
methods and systems provided herein, is of formula IA which after
halogenation or sulfonation (including sulfation) results in the
compound of formula IIA:
##STR00020##
[0347] wherein, n is 2-10; m is 0-5; and q is 1-5;
[0348] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0349] X is a halogen selected from fluoro, chloro, bromo, and
iodo; --SO.sub.3H; or --OSO.sub.2OH.
[0350] Examples of substituted or unsubstituted alkynes include,
but not limited to, acetylene, propyne, chloro propyne, bromo
propyne, butyne, pentyne, hexyne, etc.
[0351] It is to be understood that R substitutent(s) can be on one
carbon atom or on more than 1 carbon atom depending on the number
of R and carbon atoms. For example only, when n is 3 and m is 2,
the substituents R can be on the same carbon atom or on two
different carbon atoms.
[0352] In some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting or oxidizing the metal ion from a lower
oxidation state to a higher oxidation state at the anode; and
treating the anode electrolyte comprising the metal ion in the
higher oxidation state with an unsaturated hydrocarbon. In some
embodiments of the method, the method includes contacting a cathode
with a cathode electrolyte and forming an alkali at the cathode. In
some embodiments of the method, the method includes contacting a
cathode with a cathode electrolyte and forming an alkali, water,
and/or hydrogen gas at the cathode. In some embodiments of the
method, the method includes contacting a gas-diffusion cathode with
a cathode electrolyte and forming an alkali or water at the
cathode. In some embodiments, there are provided methods that
include contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; converting the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte; forming an alkali,
water, and/or hydrogen gas at the cathode; and treating the anode
electrolyte comprising the metal ion in the higher oxidation state
with an unsaturated hydrocarbon. In some embodiments, there are
provided methods that include contacting an anode with a metal ion
in an anode electrolyte in an anode chamber; converting the metal
ion from a lower oxidation state to a higher oxidation state at the
anode; contacting a gas-diffusion cathode with a cathode
electrolyte; forming an alkali or water at the cathode; and
treating the anode electrolyte comprising the metal ion in the
higher oxidation state with an unsaturated hydrocarbon. In some
embodiments, there are provided methods that include contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
converting the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a gas-diffusion cathode
with a cathode electrolyte; forming an alkali at the cathode; and
treating the anode electrolyte comprising the metal ion in the
higher oxidation state with an unsaturated hydrocarbon. In some
embodiments, the treatment of the unsaturated hydrocarbon with the
metal ion in the higher oxidation state may be inside the cathode
chamber or outside the cathode chamber. In some embodiments, the
treatment of the metal ion in the higher oxidation state with the
unsaturated hydrocarbon results in chloro, bromo, iodo, or
sulfohydrocarbons and the metal ion in the lower oxidation state.
In some embodiments, the metal ion in the lower oxidation state is
re-circulated back to the anode chamber.
[0353] In some embodiments of the above described methods, the
anode does not produce chlorine gas. In some embodiments of the
above described methods, the treatment of the unsaturated
hydrocarbon with the metal ion in the higher oxidation state does
not require oxygen gas and/or chlorine gas. In some embodiments of
the above described methods, the anode does not produce chlorine
gas and the treatment of the unsaturated hydrocarbon with the metal
ion in the higher oxidation state does not require oxygen gas
and/or chlorine gas.
[0354] In some embodiments, there are provided systems that include
an anode chamber including an anode in contact with a metal ion in
an anode electrolyte wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state;
and a reactor operably connected to the anode chamber and
configured to react the anode electrolyte comprising the metal ion
in the higher oxidation state with unsaturated hydrocarbon. In some
embodiments of the systems, the system includes a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form an alkali, water, and/or hydrogen gas in the
cathode electrolyte. In some embodiments of the systems, the system
includes a cathode chamber including a cathode with a cathode
electrolyte wherein the cathode is configured to form an alkali
and/or hydrogen gas in the cathode electrolyte. In some embodiments
of the systems, the system includes a gas-diffusion cathode with a
cathode electrolyte wherein the cathode is configured to form an
alkali or water in the cathode electrolyte. In some embodiments,
there are provided systems that include an anode chamber including
an anode with a metal ion in an anode electrolyte wherein the anode
is configured to convert the metal ion from a lower oxidation state
to a higher oxidation state in the anode chamber; a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form an alkali, water or hydrogen gas in the
cathode electrolyte; and a reactor operably connected to the anode
chamber and configured to react the anode electrolyte comprising
the metal ion in the higher oxidation state with an unsaturated
hydrocarbon. In some embodiments, there are provided systems that
include an anode chamber including an anode with a metal ion in an
anode electrolyte wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state
in the anode chamber; a cathode chamber including a gas-diffusion
cathode with a cathode electrolyte wherein the cathode is
configured to form an alkali in the cathode electrolyte; and a
reactor operably connected to the anode chamber and configured to
react the anode electrolyte comprising the metal ion in the higher
oxidation state with an unsaturated hydrocarbon. In some
embodiments, the treatment of the unsaturated hydrocarbon with the
metal ion in the higher oxidation state may be inside the cathode
chamber or outside the cathode chamber. In some embodiments, the
treatment of the metal ion in the higher oxidation state with the
unsaturated hydrocarbon results in chloro, bromo, iodo, or
sulfohydrocarbons and the metal ion in the lower oxidation state.
In some embodiments, the system is configured to form the metal ion
in the lower oxidation state from the metal ion in the higher
oxidation state with the unsaturated hydrocarbon and re-circulate
the metal ion in the lower oxidation state back to the anode
chamber.
[0355] In some embodiments, the unsaturated hydrocarbon in the
aforementioned method and system embodiments and as described
herein is of formula I or is C2-C10 alkene or C2-C5 alkene. In some
embodiments of the methods and systems described as above, the
unsaturated hydrocarbon in the aforementioned embodiments and as
described herein is, ethylene. The halohydrocarbon formed from such
unsaturated hydrocarbon is of formula II (as described herein),
e.g., ethylene dichloride, chloroethanol, butyl chloride,
dichlorobutane, chlorobutanol, etc. In some embodiments of the
methods and systems described as above, the metal ion is a metal
ion described herein, such as, but not limited to, copper, iron,
tin, or chromium.
[0356] In some embodiments of the above described systems, the
anode is configured to not produce chlorine gas. In some
embodiments of the above described systems, the reactor configured
to react the unsaturated hydrocarbon with the metal ion in the
higher oxidation state, is configured to not require oxygen gas
and/or chlorine gas. In some embodiments of the above described
methods, the anode is configured to not produce chlorine gas and
the reactor is configured to not require oxygen gas and/or chlorine
gas.
[0357] An example of the electrochemical system of FIG. 5A, is as
illustrated in FIG. 8A. It is to be understood that the system 800
of FIG. 8A is for illustration purposes only and other metal ions
with different oxidations states, other unsaturated hydrocarbons,
and other electrochemical systems forming products other than
alkali, such as water or hydrogen gas in the cathode chamber, are
equally applicable to the system. The cathode of FIG. 4A or 4B may
also be substituted in FIG. 8A. In some embodiments, as illustrated
in FIG. 8A, the electrochemical system 800 includes an oxygen
depolarized cathode that produces hydroxide ions from water and
oxygen. The system 800 also includes an anode that converts metal
ions from 1+ oxidation state to 2+ oxidation state. The Cu.sup.2+
ions combine with chloride ions to form CuCl.sub.2. The metal
chloride CuCl.sub.2 can be then reacted with an unsaturated
hydrocarbon, such as, but not limited to, ethylene to undergo
reduction of the metal ion to lower oxidation state to form CuCl
and dichlorohydrocarbon, such as, but not limited to, ethylene
dichloride. The CuCl is then re-circulated back to the anode
chamber for conversion to CuCl.sub.2.
[0358] The ethylene dichloride formed by the methods and systems of
the invention can be used for any commercial purposes. In some
embodiments, the ethylene dichloride is subjected to vinyl chloride
monomer (VCM) formation through the process such as
cracking/purification. The vinyl chloride monomer may be used in
the production of polyvinylchloride. In some embodiments, the
hydrochloric acid formed during the conversion of EDC to VCM may be
separated and reacted with acetylene to further form VCM.
[0359] In some embodiments, the HCl generated in the process of VCM
formation may be circulated to one or more of the electrochemical
systems described herein where HCl is used in the cathode or anode
electrolyte to form hydrogen gas or water at the cathode. As in
FIG. 8B, an integrated electrochemical system of the invention is
illustrated in combination with the VCM/PVC synthesis. Any of the
electrochemical systems of the invention such as system illustrated
in FIG. 1B, 2, 4A or 5A may be used to form CuCl.sub.2 which when
reacted with ethylene results in EDC. The cracking of EDC with
subsequent processing of VCM produces HCl which may be circulated
to any of the electrochemical systems of FIG. 4B or 5B to further
form CuCl.sub.2. It is to be understood that the whole process may
be conducted with only system of FIG. 4B or 5B (i.e. with no
incorporation of systems of FIG. 1B, 2, 4A or 5A).
[0360] In some embodiments, the chlorination of ethylene in an
aqueous medium with metal chloride in the higher oxidation state,
results in ethylene dichloride, chloroethanol, or combination
thereof. In some embodiments of the methods and systems described
herein, there is a formation of more than 10 wt %; or more than 20
wt %, or more than 30 wt %, or more than 40 wt %, or more than 50
wt %, or more than 60 wt %, or more than 70 wt %, or more than 80
wt %, or more than 90 wt %, or more than 95 wt %, or about 99 wt %,
or between about 10-99 wt %, or between about 10-95 wt %, or
between about 15-95 wt %, or between about 25-95 wt %, or between
about 50-95 wt %, or between about 50-99 wt % ethylene dichloride,
or between about 50-99.9 wt % ethylene dichloride, or between about
50-99.99 wt % ethylene dichloride, from ethylene. In some
embodiments, the remaining weight percentage is of chloroethanol.
In some embodiments, no chloroethanol is formed in the reaction. In
some embodiments, less than 0.001 wt % or less than 0.01 wt % or
less than 0.1 wt % or less than 0.5 wt % or less than 1 wt % or
less than 5 wt % or less than 10 wt % or less than 20 wt % of
chloroethanol is formed with the remaining EDC in the reaction. In
some embodiments, less than 0.001 wt % or less than 0.01 wt % or
less than 0.1 wt % or less than 0.5 wt % or less than 1 wt % or
less than 5 wt % of metal ion is present in EDC product. In some
embodiments, less than 0.001 wt % or less than 0.01 wt % or less
than 0.1 wt % of chloroethanol and/or metal ion is present in the
EDC product.
[0361] In some embodiments, the EDC product containing the metal
ion may be subjected to washing step which may include rinsing with
an organic solvent or passing the EDC product through a column to
remove the metal ions. In some embodiments, the EDC product may be
purified by distillation where any of the side products such as
chloral (CCl.sub.3CHO) and/or chloral hydrate
(2,2,2-trichloroethane-1,1-diol), if formed, may be separated.
[0362] In some embodiments, the unsaturated hydrocarbon is propene.
In some embodiments, the metal ion in the higher oxidation state
such as CuCl.sub.2 is treated with propene to result in propane
dichloride (C.sub.3H.sub.6Cl.sub.2) or dichloropropane (DCP) which
can be used to make allyl chloride (C.sub.3H.sub.5Cl). In some
embodiments, the unsaturated hydrocarbon is butane or butylene. In
some embodiments, the metal ion in the higher oxidation state such
as CuCl.sub.2 is treated with butene to result in butane dichloride
(C.sub.4H.sub.8Cl.sub.2) or dichlorobutene (C.sub.4H.sub.6Cl.sub.2)
which can be used to make chloroprene (C.sub.4H.sub.5Cl). In some
embodiments, the unsaturated hydrocarbon is benzene. In some
embodiments, the metal ion in the higher oxidation state such as
CuCl.sub.2 is treated with benzene to result in chlorobenzene. In
some embodiments, the metal ion in the higher oxidation state such
as CuCl.sub.2 is treated with acetylene to result in
chloroacetylene, dichloroacetylene, vinyl chloride, dichloroethene,
tetrachloroethene, or combination thereof. In some embodiments, the
unsaturated hydrocarbon is treated with metal chloride in higher
oxidation state to form a product including, but not limited to,
ethylene dichloride, chloroethanol, chloropropene, propylene oxide
(further dehydrochlorinated), allyl chloride, methyl chloride,
trichloroethylene, tetrachloroethene, chlorobenzene,
1,2-dichloroethane, 1,1,2-trichloroethane,
1,1,2,2-tetrachloroethane, pentachloroethane, 1,1-dichloroethene,
chlorophenol, chlorinated toluene, etc.
[0363] There are provided methods and systems that relate to the
halogenation, such as e.g. chlorination of the propylene for the
generation of one or more products comprising dichloropropane or
1,2-dichloropropane (DCP) and/or propylene chlorohydrin (PCH);
hydrolysis of the DCP to the PCH (when the DCP is formed); and
further reaction of the PCH to form the propylene oxide (PO) (by
dehydrochlorination). It is to be understood that other halides
such as e.g. only, iodide system or bromide system may also be used
so that the bromination of the propylene forms one or more products
comprising dibromopropane or 1,2-dibromopropane (DBP) and/or
propylene bromohydrin (PBH); hydrolysis of the DBP to the PBH; and
further reaction of the PBH to form the propylene oxide (PO) (by
dehydrobromination). In some embodiments the halogenation, such as
e.g. chlorination or bromination or iodination is done using metal
halide solution with metal ions in higher oxidation state. There
are also provided methods and systems for separation/purification
of the products from the metal ion solution; regeneration of the
metal halide with metal ions in the higher oxidation state;
recycling of the metal ion solution back to the chlorination or
bromination or iodination reaction; and recycling of other side
products.
[0364] Applicants have devised methods and systems to form the PCH
and/or DCP in high yields and high selectivity where either the
side products are not formed, or are formed in low yields, or are
converted to the PCH, DCP, and/or propylene (bromination would
yield corresponding bromide products or iodination would yield
corresponding iodide products). Applicants have also devised
methods and systems to convert the side products back either to the
propylene or to the PCH (or PBH) such that the PCH (or the PBH) is
formed in high yield and with high selectivity. Further Applicants
have devised methods and systems to form the PO from the PCH (or
the PBH) in high yield and with high selectivity. Applicants have
devised methods and systems to form the PO with reduced waste
water, resulting in economical and environmentally friendly methods
to form the PO.
[0365] The combination of methods and systems used to form the PCH
or PBH from the propylene and further to form the PO relate to
various combinations of an electrochemical method/system, a
halogenation method/system, an oxyhalogenation method/system, a
hydrolysis method/system, and an epoxidation method/system, to form
the PO. The electrochemical and the halogenation methods and
systems have been described herein. The oxyhalogenation and the
epoxidation methods and systems have been described in U.S. patent
application Ser. No. 15/963,637, filed Apr. 26, 2018, which is
incorporated herein by reference in its entirety.
[0366] Illustrated in FIG. 30 is a block flow diagram for the
formation of the PO from the propylene. In block 3, is shown an
electrochemical reaction/cell where the metal ions of the metal
halide in the lower oxidation state and the higher oxidation state
are illustrated as CuX.sub.z (a mixture of CuX and CuX.sub.2 where
X is a halide such as Cl or Br or I and z is an integer between
1-2). It is to be understood that metal halide other than copper
halide are well within the scope of the invention and have been
listed herein. Further, the integer z can be any integer depending
on the valency of the metal ion. Metal ions are oxidized from the
lower oxidation state to the higher oxidation state at the anode
where cathode reaction includes formation of sodium hydroxide.
Other cathode reactions are also possible and have been described
in detail herein. For example, in some embodiments, the cathode
electrolyte comprises water and the cathode is an oxygen
depolarizing cathode that reduces oxygen and water to hydroxide
ions; the cathode electrolyte comprises water and the cathode is a
hydrogen gas producing cathode that reduces water to hydrogen gas
and hydroxide ions; the cathode electrolyte comprises hydrochloric
acid and the cathode is a hydrogen gas producing cathode that
reduces hydrochloric acid to hydrogen gas; or the cathode
electrolyte comprises hydrochloric acid and the cathode is an
oxygen depolarizing cathode that reacts hydrochloric acid and
oxygen gas to form water.
[0367] The anolyte from the anode chamber containing saltwater such
as an aqueous stream of alkali metal halide e.g. sodium halide,
such as e.g. sodium chloride or sodium bromide or sodium iodide
(any other salt may be used including but not limited to, alkali
metal halide such as potassium halide or alkaline earth metal
halide such as calcium halide), water and CuX.sub.z is then
transferred to the halogenation reaction/reactor shown in block 1.
In block 1, the propylene C.sub.3H.sub.6 is converted into the DCP
and/or the PCH (or DBP and/or PBH in the copper bromide system)
using copper chloride (II), simultaneously reducing two Cu(II) ions
to Cu(I). The reactions are as shown below:
C.sub.3H.sub.6+2CuCl.sub.2.fwdarw.ClCH.sub.2CH(Cl)CH.sub.3(DCP)+2CuCl
C.sub.3H.sub.6+2CuCl.sub.2+H.sub.2O.fwdarw.ClCH.sub.2CH(OH)CH.sub.3(PCH)-
+2CuCl+HCl
[0368] Similar reactions take place in the bromide or iodide
system. The "propylene chlorohydrin" or "PCH", as used herein
includes PCH in its isomeric form, such as, 1-chloro-2-propanol,
2-chloro-1-propanol, or both. The "propylene bromohydrin" or "PBH",
as used herein includes PBH in its isomeric form, such as,
1-bromo-2-propanol, 2-bromo-1-propanol, or both. Without being
limited by any theory, both isomers may be formed and both may be
subsequently converted to the PO. The explicit declaration of one
isomer may not be construed as the absence of the other.
[0369] In block 2, some of the Cu(I) produced in block 1 is
regenerated using chemical oxidation in oxyhalogenation
reaction/reactor using oxidants such as, but not limited to,
O.sub.2; X.sub.2 gas alone; or HX gas and/or HX solution in
combination with gas comprising oxygen or ozone; or hydrogen
peroxide; or HXO or salt thereof; or HXO.sub.3 or salt thereof; or
HXO.sub.4 or salt thereof; or combinations thereof, wherein each X
independently is a halogen selected from fluorine, chlorine,
iodine, and bromine. For example, chlorine gas may be used to
oxidize the metal halide from the lower to the higher oxidation
state. For example, CuCl may be oxidized to CuCl.sub.2 in the
presence of chlorine gas as follows:
2CuCl+Cl.sub.2.fwdarw.2CuCl.sub.2
[0370] In some embodiments, the oxidant is HCl or HBr gas and/or
HCl or HBr solution in combination with gas comprising oxygen. An
example is as follows:
2CuCl+2HCl+1/2O.sub.2.fwdarw.2 CuCl.sub.2+H.sub.2O
[0371] In some embodiments, the oxidant is HX gas and/or HX
solution in combination with hydrogen peroxide, wherein X is a
halogen. One example is as follows:
2CuCl+H.sub.2O.sub.2+2HCl.fwdarw.2 CuCl.sub.2+2 H.sub.2O
[0372] The oxidants have been described in U.S. patent application
Ser. No. 15/963,637, filed Apr. 26, 2018, which is incorporated
herein by reference in its entirety. It is to be understood that
any equation illustrated herein with the chloride ions is equally
applicable to the bromide ions to represent the bromide systems or
iodide ions to represent the iodide systems. Hydrochloric acid
(HCl) or hydrobromic acid (HBr) is a common by-product in numerous
chemical processes. One side product of the chlorination or
bromination reaction of the propylene to the PCH or PBH is also HCl
or HBr, respectively. The methods and systems provided herein can
leverage the HCl or HBr in the oxyhalogenation step as a mechanism
to provide additional copper oxidation. The HCl or HBr can also be
sourced from other reactions and is labeled as "other HX" in
figures. The incorporation of HCl or HBr from halogenation reaction
or other reactions may lead to additional PO production by
upgrading these streams to more valuable products. The reuse of the
HCl or HBr in oxyhalogenation process allows for the reduction of
the base consumption to neutralize the acid which may improve
overall economics, especially in cases where the base could
otherwise be sold.
[0373] It is to be understood that the processes illustrated in
FIG. 30, such as electrochemical reaction, halogenation reaction,
and the oxyhalogenation reaction, may each be individually carried
out or may be in combination with one or more other processes. For
example, the electrochemically generated CuCl.sub.2 may be used in
one reactor for the chlorination of the propylene to the PCH and/or
the DCP and the chemically generated CuCl.sub.2 (via
oxychlorination) may be used in another propylene chlorination
reactor each with the option of making the PCH directly or making
the DCP with subsequent conversion to the PCH, all such
configurations are within the scope of the present disclosure.
Similarly, the electrochemically generated CuBr.sub.2 may be used
in one reactor for the bromination of the propylene to the PBH
and/or the DBP and the chemically generated CuBr.sub.2 (via
oxybromination) may be used in another propylene bromination
reactor each with the option of making the PBH directly or making
the DBP with subsequent conversion to the PBH, all such
configurations are within the scope of the present disclosure.
Similarly, the electrochemically generated CuI.sub.t may be used in
one reactor for the iodination of the propylene to the PIH
(propylene iodohydrin) and/or the DIP (diiodopropane) and the
chemically generated CuI.sub.t (via oxyiodination) may be used in
another propylene iodination reactor each with the option of making
the PIE directly or making the DIP with subsequent conversion to
the PIH, all such configurations are within the scope of the
present disclosure.
[0374] In one aspect, the oxyhalogenation reaction/reactor oxidizes
the metal ion of the metal halide in the lower oxidation state to
the higher oxidation state in the presence of the oxidant (and in
the absence of any electrochemical reaction/cell) and then the
metal halide with the metal ion in the higher oxidation state is
then transferred to the halogenation reaction/reactor to halogenate
propylene, as illustrated in FIG. 31. In block 2, is shown an
oxyhalogenation reaction/reactor where the metal ions of the metal
halide in the lower oxidation state and the higher oxidation state
are illustrated as CuX.sub.z (e.g. a mixture of CuCl and CuCl.sub.2
or a mixture of CuBr and CuBr.sub.2 or a mixture of CuI and
CuI.sub.t). Metal ions are oxidized from the lower oxidation state
to the higher oxidation state in the oxyhalogenation
reaction/reactor. The solution from the oxyhalogenation
reaction/reactor containing CuX.sub.z is then transferred to the
halogenation reaction/reactor shown in block 1. In block 1, the
propylene C.sub.3H.sub.6 is converted into the DCP and/or the PCH
using copper chloride (II) (or DBP and/or the PBH using copper
bromide (II)), simultaneously reducing two Cu(II) ions to Cu(I). It
is to be understood that the electrochemical reaction/cell and the
oxyhalogenation reaction/reactor may independently be carried out
for the oxidation of the metal halide (such as FIG. 31 for the
oxyhalogenation reaction/reactor) or may be carried out in
combination (such as FIG. 30).
[0375] As shown in FIG. 30, additional oxidation of the metal ion
from the lower oxidation state to the higher oxidation state, e.g.
CuCl to CuCl.sub.2, may be done electrochemically in block 3.
Overall, the oxidation done in blocks 2 and 3 may equal the amount
of reduction accomplished in 1. The flow of copper halide, e.g.
copper chloride or bromide between the electrochemical,
halogenation, and the oxyhalogenation systems may be either
clockwise or counter clockwise as indicated by the circular arrows.
That is, the order of operations between the three units is
flexible. The propylene chlorohydrin or bromohydrin formed in 1 is
converted to propylene oxide in the epoxidation reaction/reactor
shown as block 4. The reaction may be as shown below:
ClCH.sub.2CH(OH)CH.sub.3+NaOH.fwdarw.H.sub.2C(O)CHCH.sub.3(PO)+NaCl+H.su-
b.2O
[0376] In order to improve the yield and selectivity (or space time
yield (STY)) of the PO, it is essential to form the PCH or PBH with
high yield and high selectivity. The methods and system herein
provide various ways to form the PCH or PBH with high yield and
high selectivity and to subsequently also form the PO with high
yield and high selectivity.
Forming the PCH or PBH Under Reaction Conditions
[0377] In one aspect, there are provided methods that include
chlorinating or brominating propylene in an aqueous medium
comprising metal chloride or metal bromide with metal ion in higher
oxidation state and salt under reaction conditions to result in one
or more products comprising PCH or PBH, respectively, and the metal
chloride or metal bromide with the metal ion in lower oxidation
state. The halogenation reaction may take place after the
electrochemical reaction and/or the oxyhalogenation reaction.
[0378] In some embodiments, there are provided methods that include
(i) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
chloride and saltwater; contacting a cathode with a cathode
electrolyte in the electrochemical cell; applying voltage to the
anode and the cathode and oxidizing the metal chloride with metal
ion in a lower oxidation state to a higher oxidation state at the
anode; and (ii) withdrawing the anode electrolyte from the
electrochemical cell and chlorinating propylene with the anode
electrolyte comprising the metal chloride with the metal ion in the
higher oxidation state in the saltwater under reaction conditions
to result in one or more products comprising PCH and the metal
chloride with the metal ion in the lower oxidation state. In some
embodiments, there are provided methods that include (i) contacting
an anode with an anode electrolyte in an electrochemical cell
wherein the anode electrolyte comprises metal bromide and
saltwater; contacting a cathode with a cathode electrolyte in the
electrochemical cell; applying voltage to the anode and the cathode
and oxidizing the metal bromide with metal ion in a lower oxidation
state to a higher oxidation state at the anode; and (ii)
withdrawing the anode electrolyte from the electrochemical cell and
brominating propylene with the anode electrolyte comprising the
metal bromide with the metal ion in the higher oxidation state in
the saltwater under reaction conditions to result in one or more
products comprising PBH and the metal bromide with the metal ion in
the lower oxidation state.
[0379] In some embodiments, there are provided methods that include
(i) oxidizing metal chloride with metal ion in a lower oxidation
state to a higher oxidation state in presence of an oxidant in an
oxychlorination reaction; and (ii) withdrawing the metal chloride
with metal ion in the higher oxidation state from the
oxychlorination reaction and chlorinating propylene with the metal
chloride with the metal ion in the higher oxidation state in
saltwater under reaction conditions to result in one or more
products comprising PCH and the metal chloride with the metal ion
in the lower oxidation state. In some embodiments, there are
provided methods that include (i) oxidizing metal bromide with
metal ion in a lower oxidation state to a higher oxidation state in
presence of an oxidant in an oxybromination reaction; and (ii)
withdrawing the metal bromide with metal ion in the higher
oxidation state from the oxybromination reaction and brominating
propylene with the metal bromide with the metal ion in the higher
oxidation state in saltwater under reaction conditions to result in
one or more products comprising PBH and the metal bromide with the
metal ion in the lower oxidation state.
[0380] In some embodiments of the aforementioned aspect and
embodiments, the methods further include (iii) epoxidizing the PCH
or the PBH with a base to form PO.
[0381] An illustration of the halogenation reaction is shown in
FIG. 32. In some embodiments, the propylene may be supplied under
pressure in the liquid phase and/or the gas phase and the metal
halide, for example only, copper (II) chloride (also containing
copper (I) chloride) or copper (II) bromide (also containing copper
(I) bromide) is supplied in an aqueous solution such as saltwater.
The reaction may occur in the liquid phase where the dissolved
propylene reacts with the copper (II) halide. As illustrated in
FIG. 32, the halogenation of the propylene in the presence of the
metal halide with the metal ion in the higher oxidation state (e.g.
CuCl.sub.2 or CuBr.sub.2) may result in one or more products such
as, but not limited to, PCH, DCP, isopropanol, and isopropyl
chloride (or PBH, DBP, isopropanol, and isopropyl bromide for
corresponding bromide system). Applicants have found that in order
to form the PCH or the PBH in high space time yield (to minimize
reactor costs) with high selectivity (to minimize propylene costs)
certain reactions conditions may be controlled and used. Such
reaction conditions include, but are not limited to, temperature
and pressure in the halogenation reaction; use of the other DCP or
DBP; use of metal hydroxychloride or metal hydroxybromide; amount
of salt; amount of total chloride or bromide content; residence
time of the halogenation mixture; presence of a noble metal;
etc.
[0382] In some embodiments of all of the aforementioned aspect and
embodiments, the PCH or the PBH is formed with selectivity of
between about 20-100%; or between about 20-90%; or between about
20-80%; or between about 20-70%; or between about 20-60%; or
between about 20-50%; or between about 20-40%; or between about
30-100%; or between about 30-90%; or between about 30-80%; or
between about 30-70%; or between about 30-60%; or between about
30-50%; or between about 30-40%; or between about 40-100%; or
between about 40-90%; or between about 40-80%; or between about
40-70%; or between about 40-60%; or between about 40-50%; or
between about 75-100%; or between about 75-90%; or between about
75-80%; or between about 90-100%; or between about 90-99%; or
between about 90-95%. In some embodiments, the above noted
selectivity is in wt %.
[0383] In some embodiments, the STY (space time yield) of the one
or more products from propylene and/or after hydrolysis reaction of
the DCP or DBP, e.g. the STY of PCH or the PBH is 0.01, or 0.05, or
less than 0.1, or more than 0.1, or more than 0.5, or is 1, or more
than 1, or more than 2, or more than 3, or more than 4, or between
0.01-0.05, or between 0.01-0.1, or between 0.1-3, or between 0.5-3,
or between 0.5-2, or between 0.5-1, or between 3-5. As used herein
the STY is yield per time unit per reactor volume. For example, the
yield of product may be expressed in mol, the time unit in hour and
the volume in liter. The volume may be the nominal volume of the
reactor, e.g. in a packed bed reactor, the volume of the vessel
that holds the packed bed is the volume of the reactor. The STY may
also be expressed as STY based on the amount of propylene consumed
and/or based on amount of the DCP or DBP consumed to form the
product. For example only, in some embodiments, the STY of the PCH
or PBH product may be deduced from the amount of propylene consumed
and/or based on amount of the DCP or DBP consumed during the
reaction. The selectivity may be the mol of product, e.g. PCH/mol
or PBH/mol of the propylene consumed and/or PCH/mol or PBH/mol of
the DCP or DBP consumed. The yield may be the amount of the product
isolated. The purity may be the amount of the product/total amount
of all products (e.g., amount of PCH or PBH/all the organic
products formed).
[0384] Various suitable reaction conditions to form PCH or PBH have
been described herein below.
[0385] The other DCP or DBP or other sources of DCP or DBP as
mentioned herein (and illustrated in figures) includes DCP or DBP
formed as a by-product of other processes. Examples of the other
processes or sources include, but are not limited to, the
traditional chlorohydrin route to the PO or the DCP formed by the
chlorination of the propylene with chlorine. This stream is labeled
as other DCP or DBP in figures, which illustrates the various
locations in the process where this stream may be incorporated into
the process. The incorporation of this other DCP or DBP can lead to
additional PCH or PBH and PO production by upgrading these streams
to more valuable products.
[0386] In the traditional chlorohydrin process, the PCH may be
formed through the addition of hypochlorous acid (HOCl) to the
propylene. The HOCl may itself be formed by the addition of
chlorine (Cl.sub.2) to water, a reaction which co-produces a
stoichiometric amount of hydrochloric acid (HCl). To minimize
reactions of the propylene with both HCl and the direct addition of
Cl.sub.2 across the double bond, the reactor may be operated under
very dilute concentrations of HOCl and with an equivalent of base
(in the form of NaOH or CaO) to neutralize the HCl. Even under
these conditions, the formation of unwanted DCP can be significant,
representing a propylene selectivity loss on the order of 10%. This
unwanted DCP can be used as the other DCP in the methods described
herein and provide an economic use of a waste stream.
[0387] Another source of DCP (the "other DCP") is the production of
the DCP through the direct addition of chlorine to the propylene.
New or existing sources of chlorine (such as, but not limited to,
Deacon process and the chlor-alkali process) may be used to make
the DCP via direct chlorination of the propylene, similar to the
process used industrially to make ethylene dichloride from ethylene
and chlorine. This DCP formed via direct chlorination may then be
converted to the PCH using methods provided herein and ultimately
form the PO. The HCl formed as a by-product from the conversion to
the PCH would then be captured and reused.
[0388] Such methods and systems for the other sources of DCP or DBP
may be integrated with the methods and systems provided herein to
hydrolyze the DCP or DBP formed as a major product or as a waste
stream to the PCH or the PBH and then to the PO.
[0389] In some embodiments of the foregoing aspect and embodiments,
reaction conditions for the halogenation reaction comprise
temperature between 100-150.degree. C., pressure between 125-350
psig, or combination thereof.
[0390] In some embodiments of the aforementioned aspect and
embodiments, the methods to form PCH or PBH comprise reaction
conditions, such as, but not limited to, use of metal
hydroxychloride or metal hydroxybromide. Without being limited by
any theory, it is contemplated that the metal halide may react with
water and oxygen to form metal hydroxyhalide species which may be
of varying stoichiometry, such as e.g.
M.sub.x.sup.n+Cl.sub.y(OH).sub.(nx-y),
M.sub.xCl.sub.y(OH).sub.(2x-y), M.sub.xCl.sub.y(OH).sub.(3x-y) or
M.sub.xCl.sub.y(OH).sub.(4x-y), where M is the metal ion and
halogen is represented as Cl. Similar stoichiometries are formed in
bromide system. An illustration of the reaction is as shown below
taking copper bromide as an example:
2CuBr+H.sub.2O+1/2O.sub.2.fwdarw.2CuBrOH
[0391] Where the CuBrOH species represents one of many possible
copper hydroxybromide species of stoichiometry
Cu.sub.xBr.sub.y(OH).sub.(2x-y). If in reaction with the propylene,
the CuBr.sub.2 is replaced (e.g. at least partially) by a
hydroxybromide, the following reaction may take place:
C.sub.3H.sub.6(propylene)+CuBrOH+CuBr.sub.2.fwdarw.BrCH.sub.2CH(OH)CH.su-
b.3(PBH)+2CuBr
[0392] This reaction may allow for improved selectivity for the PBH
vs. the other products such as the DBP. The reaction with the
oxygen to form the metal hydroxychloride or metal hydroxybromide
species of stoichiometries as noted above, may occur in a reactor
separate from the halogenation reactor or may occur in the
halogenation reactor during the halogenation of the propylene.
Other examples of the metal hydroxybromide, without limitation
include, MoBr(OH).sub.3, MoBr.sub.2(OH).sub.2, and
MoBr.sub.3(OH).
[0393] In some embodiments of the aforementioned aspect and
embodiments, the reaction conditions in the methods to form the PCH
or the PBH comprise chlorinating or brominating in between about
1-30 wt % salt. The salt may be between 1-30 wt %; or between 5-30
wt % salt; or between about 8-30 wt %; or between 10-30 wt %; or
between 15-30 wt %; r between 20-30 wt %; or between 5-10 wt %.
[0394] "Salt" or "salt" in saltwater as used herein includes its
conventional sense to refer to a number of different types of salts
including, but not limited to, alkali metal halides such as, sodium
chloride, potassium chloride, lithium chloride, cesium chloride,
sodium bromide, potassium bromide, lithium bromide, cesium bromide,
etc.; alkaline earth metal halides such as, calcium chloride,
strontium chloride, magnesium chloride, barium chloride, calcium
bromide, strontium bromide, magnesium bromide, barium bromide, etc;
or ammonium chloride. In some embodiments of the foregoing aspects
and embodiments, the salt comprises alkali metal chloride or
alkaline earth metal chloride. In some embodiments of the foregoing
aspects and embodiments, the salt comprises alkali metal bromide or
alkaline earth metal bromide. In some embodiments, the salt (for
example only, sodium chloride, sodium bromide, calcium chloride, or
calcium bromide) in the halogenation includes between about 1-30 wt
% salt; or between 1-25 wt % salt; or between 1-20 wt % salt; or
between 1-10 wt % salt; or between 5-30 wt % salt; or between 5-20
wt % salt; or between 5-10 wt % salt; or between about 8-30 wt %
salt; or between about 8-25 wt % salt; or between about 8-20 wt %
salt; or between about 8-15 wt % salt; or between about 10-30 wt %
salt; or between about 10-25 wt % salt; or between about 10-20 wt %
salt; or between about 10-15 wt % salt; or between about 15-30 wt %
salt; or between about 15-25 wt % salt; or between about 15-20 wt %
salt; or between about 20-30 wt % salt; or between about 20-25 wt %
salt.
[0395] In some embodiments, the aqueous medium for the halogenation
reaction may contain between 5-50%; or 5-40%; or 5-30%; or 5-20%;
or 5-10%; or 50-75%; or 50-70%; or 50-65%; or 50-60% by weight of
water in the aqueous medium depending on the amount of salt and the
metal halide.
[0396] In some embodiments of the aforementioned aspect and
embodiments, the reaction conditions in the methods to form the PCH
or PBH comprise chlorinating or brominating in aquoeus medium with
total chloride or bromide content of between about 10-30 wt %. The
total chloride content is a combination of chloride from the metal
chloride as well as the chloride from the salt. The total bromide
content is a combination of the bromide from the metal bromide as
well as the bromide from the salt. Applicants surprisingly observed
that halogenation in the aqueous medium with total chloride or
bromide content between about 10-30 wt % resulted in high yield and
high selectivity of the PCH or PBH, respectively, over other side
products.
[0397] In some embodiments, the reaction conditions in the methods
to form the PCH or PBH comprise varying the incubation time or
residence time or mean residence time of the chlorination or the
bromination mixture. The "incubation time" or "residence time" or
"mean residence time" as used herein includes the time period for
which the halogenation mixture is left in the reactor at the above
noted temperatures before being taken out for the separation of the
product. In some embodiments, the residence time for the
halogenation mixture is few seconds or between about 1 sec-1 hour;
or 1 sec-10 hours; or 10 min-10 hours or more depending on the
temperature of the halogenation mixture. This residence time may be
in combination with other reaction conditions such as, e.g. the
temperature ranges and/or total chloride or bromide concentrations
provided herein. In some embodiments, the residence time for the
halogenation mixture is between about 1 sec-3 hour; or between
about 1 sec-2.5 hour; or between about 1 sec-2 hour; or between
about 1 sec-1.5 hour; or between about 1 sec-1 hour; or 10 min-3
hour; or between about 10 min-2.5 hour; or between about 10 min-2
hour; or between about 10 min-1.5 hour; or between about 10 min-1
hour; or between about 10 min-30 min; or between about 20 min-3
hour; or between about 20 min-2 hour; or between about 20 min-1
hour; or between about 30 min-3 hour; or between about 30 min-2
hour; or between about 30 min-1 hour; or between about 1 hour-2
hour; or between about 1 hour-3 hour; or between about 2 hour-3
hour, to form the PCH or PBH as noted herein.
[0398] In some embodiments, the reaction conditions in the methods
to form the PCH or PBH include carrying out the halogenation in the
presence of a noble metal. The "noble metal" as used herein
includes metals that are resistant to corrosion in moist
conditions. In some embodiments, the noble metals are selected from
ruthenium, rhodium, palladium, silver, osmium, iridium, platinum,
gold, mercury, rhenium, titanium, niobium, tantalum, and
combinations thereof. In some embodiments, the noble metal is
selected from rhodium, palladium, silver, platinum, gold, titanium,
niobium, tantalum, and combinations thereof. In some embodiments,
the noble metal is palladium, platinum, titanium, niobium,
tantalum, or combinations thereof. In some embodiments, the
foregoing noble metals may be present in 0, +2 or +4 oxidation
states as appropriate. For example only, platinum or palladium may
be present as metal or as a metal over carbon or may be present as
PtX.sub.2 or PdX.sub.2 (X is a halide) etc. In some embodiments,
the foregoing noble metal is supported on a solid. Examples of
solid support include, without limitation, carbon, zeolite,
titanium dioxide, alumina, silica, and the like. In some
embodiments, the foregoing noble metal is supported on carbon. For
example only, the catalyst is palladium or palladium over carbon.
The amount of nobel metal used in the halogenation reaction is
between 0.001M to 2M; or between 0.001-1.5M; or between about
0.001-1M; or between about 0.001-0.5M; or between about
0.001-0.05M; or between 0.01-2M; or between 0.01-1.5M; or between
0.01-1M; or between 0.01-0.5M; or between 0.1-2M; or between
0.1-1.5M; or between 0.1-1M; or between 0.1-0.5M; or between
1-2M.
[0399] In some embodiments of the foregoing aspect and embodiments,
the method to form the PCH or PBH further comprises adding platinum
or palladium to the aqueous medium. In some embodiments of the
foregoing aspect and embodiments, the platinum or palladium is in
concentration of between about 0.001-0.1M.
[0400] In some embodiments of the foregoing aspects and
embodiments, total amount of chloride or the bromide content in the
aqueous medium is between 4-15M or 4-10M. In some embodiments of
the foregoing aspects and embodiments, the aqueous medium in the
halogenation reaction comprises the metal halide in the higher
oxidation state in range of 0.1-5M or 1-5M, or 1.5-5M, the metal
halide in the lower oxidation state in range of 0.1-2M, and the
sodium halide in range of 0.1-5M or 1-5M.
Forming the PCH from the DCP or the PBH from the DBP
[0401] As illustrated in FIG. 32, DCP or DBP may be another product
formed after the halogenation (after chlorination or bromination
respectively) of propylene. The "1,2-dichloropropane" or
"dichloropropane" or "propylene dichloride" or "DCP" or "PDC" can
be used interchangeably. The "1,2-dibromopropane" or
"dibromopropane" or "propylene dibromide" or "DBP" or "PDB" can be
used interchangeably. In some embodiments, the DCP may be formed as
a major product and in one aspect, there are provided methods and
systems to convert the DCP to the PCH in the same or a separate
reactor. In some embodiments, the DBP may be formed as a major
product and in one aspect, there are provided methods and systems
to convert the DBP to the PBH in the same or a separate
reactor.
[0402] In one aspect, there are provided methods that include
chlorinating propylene in an aqueous medium comprising metal
chloride with metal ion in higher oxidation state and salt under
reaction conditions to result in one or more products comprising
DCP, and the metal chloride with the metal ion in lower oxidation
state; and hydrolyzing the DCP to PCH. In some embodiments of the
foregoing aspect, the one or more products further comprise PCH. In
some embodiments of the foregoing aspect and embodiments, the
method comprises one or more of (A) hydrolyzing the DCP to the PCH
in situ; (B) separating the DCP from the aqueous medium and/or from
the PCH (when both DCP and PCH are formed in the chlorination
reaction) and hydrolyzing the DCP to the PCH; and/or (C)
hydrolyzing the DCP to the PCH without the separation of the DCP
from the PCH and/or from the aqueous medium, to increase the yield
of the PCH.
[0403] In one aspect, there are provided methods that include
brominating propylene in an aqueous medium comprising metal bromide
with metal ion in higher oxidation state and salt under reaction
conditions to result in one or more products comprising DBP, and
the metal bromide with the metal ion in lower oxidation state; and
hydrolyzing the DBP to PBH. In some embodiments of the foregoing
aspect, the one or more products further comprise PBH. In some
embodiments of the foregoing aspect and embodiments, the method
comprises one or more of (A) hydrolyzing the DBP to the PBH in
situ; (B) separating the DBP from the aqueous medium and/or from
the PBH (when both DBP and PBH are formed in the bromination
reaction) and hydrolyzing the DBP to the PBH; and/or (C)
hydrolyzing the DBP to the PBH without the separation of the DBP
from the PBH and/or from the aqueous medium, to increase the yield
of the PBH.
[0404] The electrochemical reaction/cell, the halogenation
reaction/reactor, the oxyhalogenation reaction/reactor, the
hydrolysis reaction/reactor, and the epoxidation reaction/reactor
are all illustrated in FIG. 33.
[0405] The halogenation reaction may take place after the
electrochemical reaction and/or the oxyhalogenation reaction.
Accordingly, in some embodiments there are provided methods that
include (i) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
chloride and saltwater; contacting a cathode with a cathode
electrolyte in the electrochemical cell; applying voltage to the
anode and the cathode and oxidizing the metal chloride with metal
ion in a lower oxidation state to a higher oxidation state at the
anode; (ii) withdrawing the anode electrolyte from the
electrochemical cell and chlorinating propylene with the anode
electrolyte comprising the metal chloride with the metal ion in the
higher oxidation state in the saltwater to result in one or more
products comprising DCP and the metal chloride with the metal ion
in the lower oxidation state; and (iii) hydrolyzing the DCP to the
PCH. In some embodiments, there are provided methods that include
(i) oxidizing metal chloride with metal ion in a lower oxidation
state to a higher oxidation state in presence of an oxidant in an
oxychlorination reaction; (ii) withdrawing the metal chloride with
metal ion in the higher oxidation state from the oxychlorination
reaction and chlorinating propylene with the metal chloride with
metal ion in the higher oxidation state in saltwater to result in
one or more products comprising DCP and the metal chloride with the
metal ion in the lower oxidation state; and (iii) hydrolyzing the
DCP to the PCH. In some embodiments of the foregoing aspect and
embodiments, the one or more products further comprise PCH. In some
embodiments of the foregoing aspect and embodiments, the method
further comprises one or more of (A) hydrolyzing the DCP to the PCH
in situ; (B) separating the DCP from the aqueous medium and/or from
the PCH and then hydrolyzing the DCP to the PCH; and/or (C)
hydrolyzing the DCP to the PCH without the separation of the DCP
from the PCH and/or the aqueous medium, to increase the yield of
the PCH. In some embodiments of the aforementioned embodiments, the
methods further include (iv) epoxidizing the PCH with a base to
form PO.
[0406] In some embodiments there are provided methods that include
(i) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
bromide and saltwater; contacting a cathode with a cathode
electrolyte in the electrochemical cell; applying voltage to the
anode and the cathode and oxidizing the metal bromide with metal
ion in a lower oxidation state to a higher oxidation state at the
anode; (ii) withdrawing the anode electrolyte from the
electrochemical cell and brominating propylene with the anode
electrolyte comprising the metal bromide with the metal ion in the
higher oxidation state in the saltwater to result in one or more
products comprising DBP and the metal bromide with the metal ion in
the lower oxidation state; and (iii) hydrolyzing the DBP to the
PBH. In some embodiments, there are provided methods that include
(i) oxidizing metal bromide with metal ion in a lower oxidation
state to a higher oxidation state in presence of an oxidant in an
oxybromination reaction; (ii) withdrawing the metal bromide with
metal ion in the higher oxidation state from the oxybromination
reaction and brominating propylene with the metal bromide with
metal ion in the higher oxidation state in saltwater to result in
one or more products comprising DBP and the metal bromide with the
metal ion in the lower oxidation state; and (iii) hydrolyzing the
DBP to the PBH. In some embodiments of the foregoing aspect and
embodiments, the one or more products further comprise PBH. In some
embodiments of the foregoing aspect and embodiments, the method
further comprises one or more of (A) hydrolyzing the DBP to the PBH
in situ; (B) separating the DBP from the aqueous medium and/or from
the PBH and then hydrolyzing the DBP to the PBH; and/or (C)
hydrolyzing the DBP to the PBH without the separation of the DBP
from the PBH and/or the aqueous medium, to increase the yield of
the PBH. In some embodiments of the aforementioned embodiments, the
methods further include (iv) epoxidizing the PBH with a base to
form PO.
[0407] In one aspect, there is provided a system comprising (i) an
electrochemical cell comprising an anode chamber comprising an
anode and an anode electrolyte wherein the anode electrolyte
comprises metal chloride and saltwater and anode is configured to
oxidize metal chloride with metal ion in a lower oxidation state to
a higher oxidation state; a cathode chamber comprising a cathode
and a cathode electrolyte; and a voltage source configured to apply
voltage to the anode and the cathode; (ii) a chlorination reactor
operably connected to the anode chamber of the electrochemical cell
and configured to obtain the anode electrolyte and chlorinate
propylene with the anode electrolyte comprising the metal chloride
with the metal ion in the higher oxidation state in the saltwater
to result in one or more products comprising DCP and the metal
chloride with the metal ion in the lower oxidation state; (iii) a
hydrolysis reactor operably connected to the chlorination reactor
and configured to obtain the one or more products comprising DCP
from the chlorination reactor with or without the saltwater
comprising metal chloride and configured to hydrolyze the DCP to
the PCH; and (iv) an epoxidation reactor operably connected to the
hydrolysis reactor and configured to obtain the solution comprising
DCP and PCH and epoxidize the PCH to PO in presence of a base. In
some embodiments, the system further comprises an oxychlorination
reactor operably connected to the chlorination reactor and/or the
electrochemical cell, and the hydrolysis reactor and configured to
obtain aqueous medium from the chlorination reactor and/or the
electrochemical cell comprising the metal chloride with metal ion
in the lower oxidation state and the higher oxidation state and
obtain HCl produced in the hydrolysis reactor and configured to
oxidize the metal chloride with metal ion in the lower oxidation
state to the higher oxidation state using an oxidant comprising the
HCl and oxygen, or hydrogen peroxide (or any other oxidant as
described herein).
[0408] In one aspect, there is provided a system comprising (i) an
electrochemical cell comprising an anode chamber comprising an
anode and an anode electrolyte wherein the anode electrolyte
comprises metal bromide and saltwater and anode is configured to
oxidize metal bromide with metal ion in a lower oxidation state to
a higher oxidation state; a cathode chamber comprising a cathode
and a cathode electrolyte; and a voltage source configured to apply
voltage to the anode and the cathode; (ii) a bromination reactor
operably connected to the anode chamber of the electrochemical cell
and configured to obtain the anode electrolyte and brominate
propylene with the anode electrolyte comprising the metal bromide
with the metal ion in the higher oxidation state in the saltwater
to result in one or more products comprising DBP and the metal
bromide with the metal ion in the lower oxidation state; (iii) a
hydrolysis reactor operably connected to the bromination reactor
and configured to obtain the one or more products comprising DBP
from the bromination reactor with or without the saltwater
comprising metal bromide and configured to hydrolyze the DBP to the
PBH; and (iv) an epoxidation reactor operably connected to the
hydrolysis reactor and configured to obtain the solution comprising
DBP and PBH and epoxidize the PBH to PO in presence of a base. In
some embodiments, the system further comprises an oxybromination
reactor operably connected to the bromination reactor and/or the
electrochemical cell, and the hydrolysis reactor and configured to
obtain aqueous medium from the bromination reactor and/or the
electrochemical cell comprising the metal bromide with metal ion in
the lower oxidation state and the higher oxidation state and obtain
HBr produced in the hydrolysis reactor and configured to oxidize
the metal bromide with metal ion in the lower oxidation state to
the higher oxidation state using an oxidant comprising the HBr
and/or oxygen, or hydrogen peroxide (or any other oxidant as
described herein).
[0409] In one aspect, the oxyhalogenation reactor is used
independent of the electrochemical cell. In some embodiments, there
is provided a system comprising (i) oxychlorination reactor
configured to oxidize metal chloride with metal ion in lower
oxidation state to higher oxidation state using an oxidant
comprising HCl and oxygen, or hydrogen peroxide (or any other
oxidant as described herein); (ii) a chlorination reactor operably
connected to the oxychlorination reactor and configured to obtain
the metal chloride with the metal ion in the higher oxidation state
and chlorinate propylene with the metal chloride with the metal ion
in the higher oxidation state in saltwater to result in one or more
products comprising DCP and the metal chloride with the metal ion
in the lower oxidation state; (iii) a hydrolysis reactor operably
connected to the chlorination reactor and configured to obtain the
one or more products comprising DCP from the chlorination reactor
with or without the saltwater comprising metal chloride and
configured to hydrolyze the DCP to the PCH; and (iv) an epoxidation
reactor operably connected to the hydrolysis reactor and configured
to obtain the solution comprising DCP and PCH and epoxidize the PCH
to PO in presence of a base. In some embodiments, the
oxychlorination reactor is also operably connected to the
chlorination reactor and the hydrolysis reactor and is configured
to obtain the aqueous medium from the chlorination reactor
comprising the metal chloride with metal ion in the lower oxidation
state and the higher oxidation state and is configured to obtain
HCl produced in the hydrolysis reactor.
[0410] In some embodiments, there is provided a system comprising
(i) oxybromination reactor configured to oxidize metal bromide with
metal ion in lower oxidation state to higher oxidation state using
an oxidant comprising HBr and/or oxygen, or hydrogen peroxide (or
any other oxidant as described herein); (ii) a bromination reactor
operably connected to the oxybromination reactor and configured to
obtain the metal bromide with the metal ion in the higher oxidation
state and brominate propylene with the metal bromide with the metal
ion in the higher oxidation state in saltwater to result in one or
more products comprising DBP and the metal bromide with the metal
ion in the lower oxidation state; (iii) a hydrolysis reactor
operably connected to the bromination reactor and configured to
obtain the one or more products comprising DBP from the bromination
reactor with or without the saltwater comprising metal bromide and
configured to hydrolyze the DBP to the PBH; and (iv) an epoxidation
reactor operably connected to the hydrolysis reactor and configured
to obtain the solution comprising DBP and PBH and epoxidize the PBH
to PO in presence of a base. In some embodiments, the
oxybromination reactor is also operably connected to the
bromination reactor and the hydrolysis reactor and is configured to
obtain the aqueous medium from the bromination reactor comprising
the metal bromide with metal ion in the lower oxidation state and
the higher oxidation state and is configured to obtain HBr produced
in the hydrolysis reactor.
[0411] In some embodiments, the conversion of the DCP to the PCH is
a hydrolysis reaction:
[0412]
ClCH.sub.2CH(Cl)CH.sub.3+H.sub.2O.fwdarw.ClCH.sub.2CH(OH)CH.sub.3+H-
Cl
[0413]
ClCH.sub.2CH(Cl)CH.sub.3+H.sub.2O.fwdarw.HOCH.sub.2CH(Cl)CH.sub.3+H-
Cl
[0414] In reactions above, the DCP is hydrolyzed by water into two
isomers of the PCH: 1-chloro-2-propanol and 2-chloro-1-propanol.
The conversion of the DCP to the PCH is slow at room temperature.
In some embodiments, there are provided efficient methods to
convert the DCP to the PCH by hydrolysis. Similar reactions take
place for the bromide system.
[0415] In some embodiments, the reaction conditions listed in the
foregoing sections also aid in (A) the hydrolysis of the DCP to the
PCH in situ (e.g. during chlorination reaction in the chlorination
reactor) or aid in (A) the hydrolysis of the DBP to the PBH in situ
(e.g. during bromination reaction in the bromination reactor). The
DCP may be hydrolyzed to the PCH in situ or the DBP may be
hydrolyzed to the PBH in situ by increasing the available free
water during the reaction. Because water is a reactant in the
hydrolysis, the presence of free water may lead to the higher
conversion of the DCP to the PCH or the DBP to the PBH.
[0416] In some embodiments, the DCP or the DBP may be formed in
high yield and may then be hydrolyzed to the PCH or the PBH,
respectively (B and C above). In such embodiments, some amount of
PCH or the PBH may be formed in the halogenation reaction which may
or may not be separated from the DCP or the DBP, respectively.
There may be a number of options to increase the rate and/or
selectivity of the DCP or the DBP formation. These options include
highly concentrated salt solutions which reduce the available free
water. Because water is a reactant in the hydrolysis, the presence
of free water may lead to the conversion of the DCP to the PCH or
the DBP to the PBH. The high concentrations of salt may be
accomplished through the addition of the copper halide salts (such
as CuCl.sub.2, CuCl or in combination) or through other salts such
as NaCl or NaBr. There are also a number of process conditions
which can be optimized to provide higher STY and better selectivity
for the DCP or the DBP production including temperature, pressure
(e.g. pressures under which the propylene may form a liquid or
supercritical phase), and residence time.
[0417] In one aspect, the conversion of the DCP to the PCH or the
DBP to the PBH may be executed in a second reaction step downstream
(in a separate reactor) of the propylene chlorination or
bromination, illustrated as the hydrolysis reactor in FIG. 33.
[0418] The DCP may be hydrolyzed to the PCH by (B) separating the
DCP from the aqueous medium and/or from the PCH (when both DCP and
PCH are formed in the chlorination reaction) and then hydrolyzing
the DCP to the PCH; and/or (C) hydrolyzing the DCP to the PCH
without the separation of the DCP from the PCH and/or the aqueous
medium, to increase the yield of the PCH. The DBP may be hydrolyzed
to the PBH by (B) separating the DBP from the aqueous medium and/or
from the PBH (when both DBP and PBH are formed in the bromination
reaction) and then hydrolyzing the DBP to the PBH; and/or (C)
hydrolyzing the DBP to the PBH without the separation of the DBP
from the PBH and/or the aqueous medium, to increase the yield of
the PBH.
[0419] When the hydrolysis is done in a second step, the hydrolysis
of the DCP to the PCH or the DBP to the PBH may utilize the aqueous
stream leaving the halogenation reaction/reactor (containing the
aqueous metal halide, e.g. aqueous copper chloride or copper
bromide) as part of a circulating loop (embodiment C above related
to hydrolysis without the separation of the DCP or the DBP from the
aqueous medium).
[0420] Illustrated in FIG. 33 is the aspect where the DCP is
converted to the PCH or the DBP is converted to the PBH in a
hydrolysis reaction/reactor after the halogenation
reaction/reactor.
[0421] FIG. 33 illustrates that the halogenation is divided among
two reaction blocks. Block 1 effects propylene halogenation to one
or more products comprising the DCP (and optionally the PCH too) or
the DBP (and optionally the PBH too). Block 5 in FIG. 33 uses the
aqueous copper halide stream from block 1 and hydrolyzes the DCP to
the PCH or the DBP to the PBH. To leverage the process economics of
the conversion of the DCP to the PCH or the DBP to the PBH in an
optimum way, the process may recover at least some of the HCl or
HBr by-product from the hydrolysis of the DCP to the PCH or the DBP
to the PBH (equations above). This HCl or HBr can be reused in a
traditional oxyhalogenation reaction for the production of ethylene
dichloride (EDC) or ethylene dibromide (EDB) or used in the
oxyhalogenation unit 2 within the process to generate additional
PO.
[0422] In some embodiments of the above noted aspect, the method
comprises (B) separating the DCP from the aqueous medium and/or
from the PCH and then hydrolyzing the DCP to the PCH. In some
embodiments of the above noted aspect, the method comprises (B)
separating the DBP from the aqueous medium and/or from the PBH and
then hydrolyzing the DBP to the PBH. In such embodiments, a
separation step takes place between the chlorination and the
hydrolysis.
[0423] In one aspect, there are provided methods to form PCH,
comprising: (i) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
chloride and saltwater; contacting a cathode with a cathode
electrolyte in the electrochemical cell; applying voltage to the
anode and the cathode and oxidizing the metal chloride with metal
ion in a lower oxidation state to a higher oxidation state at the
anode; (ii) withdrawing the anode electrolyte from the
electrochemical cell and chlorinating propylene in the anode
electrolyte comprising metal chloride with metal ion in higher
oxidation state and the saltwater to result in one or more products
comprising PCH and DCP, and the metal chloride with the metal ion
in lower oxidation state; (iii) separating the PCH from the aqueous
medium; and (iv) treating the aqueous medium comprising the metal
chloride with metal ions in the higher oxidation state and the
lower oxidation state and the DCP with water to hydrolyze the DCP
to the PCH. In one aspect, there are provided methods to form PBH,
comprising: (i) contacting an anode with an anode electrolyte in an
electrochemical cell wherein the anode electrolyte comprises metal
bromide and saltwater; contacting a cathode with a cathode
electrolyte in the electrochemical cell; applying voltage to the
anode and the cathode and oxidizing the metal bromide with metal
ion in a lower oxidation state to a higher oxidation state at the
anode; (ii) withdrawing the anode electrolyte from the
electrochemical cell and brominating propylene in the anode
electrolyte comprising metal bromide with metal ion in higher
oxidation state and the saltwater to result in one or more products
comprising PBH and DBP, and the metal bromide with the metal ion in
lower oxidation state; (iii) separating the PBH from the aqueous
medium; and (iv) treating the aqueous medium comprising the metal
bromide with metal ions in the higher oxidation state and the lower
oxidation state and the DBP with water to hydrolyze the DBP to the
PBH.
[0424] In one aspect, there are provided methods to form PCH,
comprising: (i) oxidizing metal chloride with metal ion in a lower
oxidation state to a higher oxidation state in presence of an
oxidant in an oxychlorination reaction; (ii) withdrawing the metal
chloride with metal ion in the higher oxidation state from the
oxychlorination reaction and chlorinating propylene with the metal
chloride with the metal ion in the higher oxidation state in
saltwater under reaction conditions to result in one or more
products comprising PCH and DCP, and the metal chloride with the
metal ion in lower oxidation state; (iii) separating the PCH from
the aqueous medium; and (iv) treating the aqueous medium comprising
the metal chloride with metal ions in the higher oxidation state
and the lower oxidation state and the DCP with water to hydrolyze
the DCP to the PCH. In one aspect, there are provided methods to
form PBH, comprising: (i) oxidizing metal bromide with metal ion in
a lower oxidation state to a higher oxidation state in presence of
an oxidant in an oxybromination reaction; (ii) withdrawing the
metal bromide with metal ion in the higher oxidation state from the
oxybromination reaction and brominating propylene with the metal
bromide with the metal ion in the higher oxidation state in
saltwater under reaction conditions to result in one or more
products comprising PBH and DBP, and the metal bromide with the
metal ion in lower oxidation state; (iii) separating the PBH from
the aqueous medium; and (iv) treating the aqueous medium comprising
the metal bromide with metal ions in the higher oxidation state and
the lower oxidation state and the DBP with water to hydrolyze the
DBP to the PBH.
[0425] In some embodiments of the foregoing aspects, the methods
further include (v) epoxidizing the PCH or the PBH with a base to
form propylene oxide (PO). The PCH or the PBH may be separated from
the aqueous stream using various separation techniques, including,
but not limited to, reactive separation, distillation, molecular
sieve, membrane, etc.
[0426] In another aspect, both the DCP and the PCH or the DBP and
the PBH are separated from the aqueous stream and the DCP is
hydrolyzed to the PCH or the DBP is hydrolyzed to the PBH in the
absence of the metal salts used in the chlorination or the
bromination of the propylene (e.g. metal chlorides used in the
chlorination of propylene). Accordingly, in one aspect, there are
provided methods to form PCH, comprising: (i) contacting an anode
with an anode electrolyte in an electrochemical cell wherein the
anode electrolyte comprises metal chloride and saltwater;
contacting a cathode with a cathode electrolyte in the
electrochemical cell; applying voltage to the anode and the cathode
and oxidizing the metal chloride with metal ion in a lower
oxidation state to a higher oxidation state at the anode; (ii)
withdrawing the anode electrolyte from the electrochemical cell and
chlorinating propylene in the anode electrolyte comprising metal
chloride with metal ion in higher oxidation state to result in one
or more products comprising PCH and DCP, and the metal chloride
with the metal ion in lower oxidation state; (iii) separating
organics comprising the PCH and the DCP from the aqueous medium
comprising the metal chloride with metal ions in the higher
oxidation state and the lower oxidation state; and (iv) hydrolyzing
the DCP (also containing PCH) with water to form the PCH. In one
aspect, there are provided methods to form PBH, comprising: (i)
contacting an anode with an anode electrolyte in an electrochemical
cell wherein the anode electrolyte comprises metal bromide and
saltwater; contacting a cathode with a cathode electrolyte in the
electrochemical cell; applying voltage to the anode and the cathode
and oxidizing the metal bromide with metal ion in a lower oxidation
state to a higher oxidation state at the anode; (ii) withdrawing
the anode electrolyte from the electrochemical cell and brominating
propylene in the anode electrolyte comprising metal bromide with
metal ion in higher oxidation state to result in one or more
products comprising PBH and DBP, and the metal bromide with the
metal ion in lower oxidation state; (iii) separating organics
comprising the PBH and the DBP from the aqueous medium comprising
the metal bromide with metal ions in the higher oxidation state and
the lower oxidation state; and (iv) hydrolyzing the DBP (also
containing PBH) with water to form the PBH.
[0427] In one aspect, there are provided methods to form PCH,
comprising: (i) oxidizing metal chloride with metal ion in a lower
oxidation state to a higher oxidation state in presence of an
oxidant in an oxychlorination reaction; (ii) withdrawing the metal
chloride with metal ion in the higher oxidation state from the
oxychlorination reaction and chlorinating propylene with the metal
chloride with the metal ion in the higher oxidation state in
saltwater under reaction conditions to result in one or more
products comprising PCH and DCP, and the metal chloride with the
metal ion in lower oxidation state; (iii) separating organics
comprising the PCH and the DCP from the aqueous medium comprising
the metal chloride with metal ions in the higher oxidation state
and the lower oxidation state; and (iv) hydrolyzing the DCP (also
containing PCH) with water to form the PCH. In one aspect, there
are provided methods to form PBH, comprising: (i) oxidizing metal
bromide with metal ion in a lower oxidation state to a higher
oxidation state in presence of an oxidant in an oxybromination
reaction; (ii) withdrawing the metal bromide with metal ion in the
higher oxidation state from the oxybromination reaction and
brominating propylene with the metal bromide with the metal ion in
the higher oxidation state in saltwater under reaction conditions
to result in one or more products comprising PBH and DBP, and the
metal bromide with the metal ion in lower oxidation state; (iii)
separating organics comprising the PBH and the DBP from the aqueous
medium comprising the metal bromide with metal ions in the higher
oxidation state and the lower oxidation state; and (iv) hydrolyzing
the DBP (also containing PBH) with water to form the PBH.
[0428] In some embodiments of the foregoing aspects, the DCP is
separated from the PCH or the DBP is separated from the PBH before
the hydrolysis step. In some embodiments of the foregoing aspects,
the method further includes (v) epoxidizing the PCH or the PBH with
a base to form propylene oxide (PO).
[0429] In some embodiments, the hydrolysis step forms HCl and the
method further comprises recirculating the HCl to the
oxychlorination step (illustrated in FIG. 33 when X is Cl) where
the metal chloride with the metal ion in the lower oxidation state
is converted to the metal chloride with the metal ion in the higher
oxidation state in presence of the HCl and/or oxygen, or hydrogen
peroxide, or any other oxidant described herein. In some
embodiments, the hydrolysis step forms HBr and the method further
comprises recirculating the HBr to the oxybromination step
(illustrated in FIG. 33 when X is Br) where the metal bromide with
the metal ion in the lower oxidation state is converted to the
metal bromide with the metal ion in the higher oxidation state in
presence of the HBr and/or oxygen, or hydrogen peroxide, or any
other oxidant described herein.
[0430] In some embodiments, the chlorination or the bromination
reaction may be run in reaction conditions, such as, at elevated
temperatures and at lower metal chloride or bromide concentration.
In such embodiments, both the PCH or PBH and the DCP or DBP may be
separated from the aqueous medium comprising metal chloride or
bromide as stated above.
[0431] In some embodiments, the step of separating the one or more
products comprising DCP or the DBP from the halogenation reaction
comprises any separation method known in the art. In some
embodiments, the one or more products comprising DCP and optionally
the PCH or the DBP and optionally the PBH may be separated from the
halogenation reaction as a vapor stream. The separated vapors may
be cooled and/or compressed and subjected to the hydrolysis
reaction. Other separation methods include, without limitation,
distillation and/or flash distillation using the distillation
column or flash distillation column. The remaining one or more
products comprising DCP and optionally the PCH or the DBP and
optionally the PBH in the aqueous medium may be further separated
using methods such as, decantation, extraction, or combination
thereof. Various examples of the separation methods are described
in detail in U.S. patent application Ser. No. 14/446,791, filed
Jul. 30, 2014, which is incorporated herein by reference in its
entirety.
[0432] In one aspect, the DCP may be used as an extraction solvent
that extracts DCP and the PCH from the aqueous stream from the
chlorination reaction/reactor. The DCP used as the extraction
solvent can be DCP from the same process that has been separated
and recirculated and/or is the other DCP. The "other DCP" has been
described herein. The extraction solvent can be any organic solvent
that removes DCP and/or the PCH from the aqueous metal ion
solution. Applicants surprisingly found that in some embodiments,
the use of DCP as the extraction solvent may ensure that the
hydrolysis reaction, which occurs in an aqueous solution with metal
chlorides (aspect above) or without metal chlorides (another aspect
above), can have the maximum rate as the aqueous medium can be
saturated with the DCP. In some embodiments, the DCP may be present
in excess amount in order to facilitate efficient hydrolysis. In
some embodiments, the mol % of the DCP is equal to or greater than
the mol % of the PCH. In some embodiments, the DCP may be as high
as 10-95% by volume; or 10-90% by volume; or 10-80% by volume; or
10-70% by volume; or 10-60% by volume; or 10-50% by volume; or
10-40% by volume; or 10-30% by volume; or 10-20% by volume, of the
total solution volume. Similarly, in one aspect, the DBP may be
used as an extraction solvent that extracts DBP and the PBH from
the aqueous stream from the bromination reaction/reactor. The DBP
used as the extraction solvent can be DBP from the same process
that has been separated and recirculated and/or is the other DBP.
The "other DBP" has been described herein. The extraction solvent
can be any organic solvent that removes DBP and/or the PBH from the
aqueous metal ion solution. Applicants surprisingly found that in
some embodiments, the use of DBP as the extraction solvent may
ensure that the hydrolysis reaction, which occurs in an aqueous
solution with metal bromides (aspect above) or without metal
bromides (another aspect above), can have the maximum rate as the
aqueous medium can be saturated with the DBP. In some embodiments,
the DBP may be present in excess amount in order to facilitate
efficient hydrolysis. In some embodiments, the mol % of the DBP is
equal to or greater than the mol % of the PBH. In some embodiments,
the DBP may be as high as 10-95% by volume; or 10-90% by volume; or
10-80% by volume; or 10-70% by volume; or 10-60% by volume; or
10-50% by volume; or 10-40% by volume; or 10-30% by volume; or
10-20% by volume, of the total solution volume.
[0433] There may be several benefits to the use of DCP or DBP as
the extraction solvent. The DCP or DBP can form a second organic
phase which may help ensure that a soluble concentration of DCP or
DBP remains in the aqueous phase. In some embodiments, further
degradation of the PCH or PBH into other products (such as, but not
limited to, acetone and/or propylene glycol) may be minimized as
the PCH may preferentially partition into the DCP phase or the PBH
may preferentially partition into the DBP phase, rather than the
aqueous phase. In a continuous operation, the PCH or PBH may be
removed from the reactor in the organic phase with the un-reacted
DCP or DBP, respectively. This last advantage may alleviate the
need to separate the PCH or PBH from the aqueous solution by other
techniques such as distillation. By extracting the PCH with the DCP
or the PBH with the DBP, the PCH or the PBH can be removed from the
halogenation reactor by removing the DCP layer or the DBP layer,
respectively, that is phase-separated from the aqueous layer.
[0434] FIG. 34 illustrates an example of the use of the DCP or DBP
as an extracting solvent. In FIG. 34, the recirculating DCP stream
serves to extract the PCH both from the propylene chlorination
reactor (block 1) and the hydrolysis reactor (block 5). Similarly,
in FIG. 34, the recirculating DBP stream serves to extract the PBH
both from the propylene bromination reactor (block 1) and the
hydrolysis reactor (block 5).
[0435] The PCH recovered from these reactors along with the DCP or
the PBH recovered from these reactors along with the DBP may be
then sent to epoxidation, where the PCH or the PBH is converted to
the PO and the DCP or the DBP stream is recirculated. In this
configuration, any DCP or the DBP made in the propylene
halogenation reactor may be balanced by conversion to the PCH or
the PBH respectively, in the hydrolysis reactor. The extracting
solvent as shown in FIG. 34 can flow either clockwise or
counterclockwise. The order of operations may be determined by
process economics. The epoxidation of the PCH to the PO in the
presence of the DCP or the PBH to the PO in the presence of the DBP
has been described below in detail.
[0436] In some embodiments, the DCP as the extraction solvent is
the DCP separated and recirculated from the same process (as
illustrated in FIG. 34) and/or is other DCP from other sources. The
process using the other DCP is as illustrated in FIG. 35. It is to
be understood that FIG. 35 illustrating the chloride system is
equally applicable to the bromide system. In this embodiment, new
or existing sources of chlorine to make the DCP via direct
chlorination of propylene, shown as block 7 in FIG. 35, is
connected to the chlorination reactor and/or the hydrolysis reactor
for the DCP to be converted to the PCH and ultimately to the PO.
The HCl formed as a by-product from the conversion to the PCH would
then be captured and reused. The direct chlorination reactor such
as traditional chlorohydrin process and/or direct chlorination of
propylene with chlorine may replace or supplement the
electrochemical and/or the oxychlorination processes provided
herein (oxychlorination shown as block 2 in FIG. 35).
[0437] Accordingly, in one aspect, there are provided methods to
form PCH, comprising: (i) contacting an anode with an anode
electrolyte in an electrochemical cell wherein the anode
electrolyte comprises metal chloride and saltwater; contacting a
cathode with a cathode electrolyte in the electrochemical cell;
applying voltage to the anode and the cathode and oxidizing the
metal chloride with metal ion in a lower oxidation state to a
higher oxidation state at the anode; (ii) withdrawing the anode
electrolyte from the electrochemical cell and chlorinating
propylene in the anode electrolyte comprising metal chloride with
metal ion in higher oxidation state to result in one or more
products comprising PCH and DCP, and the metal chloride with the
metal ion in lower oxidation state; (iii) extracting the one or
more products comprising PCH and DCP from the aqueous medium by
extracting with DCP as an extraction solvent; and (iv) hydrolyzing
the DCP with water to form the PCH. In one aspect, there are
provided methods to form PBH, comprising: (i) contacting an anode
with an anode electrolyte in an electrochemical cell wherein the
anode electrolyte comprises metal bromide and saltwater; contacting
a cathode with a cathode electrolyte in the electrochemical cell;
applying voltage to the anode and the cathode and oxidizing the
metal bromide with metal ion in a lower oxidation state to a higher
oxidation state at the anode; (ii) withdrawing the anode
electrolyte from the electrochemical cell and brominating propylene
in the anode electrolyte comprising metal bromide with metal ion in
higher oxidation state to result in one or more products comprising
PBH and DBP, and the metal bromide with the metal ion in lower
oxidation state; (iii) extracting the one or more products
comprising PBH and DBP from the aqueous medium by extracting with
DBP as an extraction solvent; and (iv) hydrolyzing the DBP with
water to form the PBH.
[0438] In one aspect, there are provided methods to form PCH,
comprising: (i) oxidizing metal chloride with metal ion in a lower
oxidation state to a higher oxidation state in presence of an
oxidant in an oxychlorination reaction; (ii) withdrawing the metal
chloride with metal ion in the higher oxidation state from the
oxychlorination reaction and chlorinating propylene with the metal
chloride with the metal ion in the higher oxidation state in
saltwater under reaction conditions to result in one or more
products comprising PCH and DCP, and the metal chloride with the
metal ion in lower oxidation state; (iii) extracting the one or
more products comprising PCH and DCP from the aqueous medium by
extracting with DCP as an extraction solvent; and (iv) hydrolyzing
the DCP with water to form the PCH. In one aspect, there are
provided methods to form PBH, comprising: (i) oxidizing metal
bromide with metal ion in a lower oxidation state to a higher
oxidation state in presence of an oxidant in an oxybromination
reaction; (ii) withdrawing the metal bromide with metal ion in the
higher oxidation state from the oxybromination reaction and
brominating propylene with the metal bromide with the metal ion in
the higher oxidation state in saltwater under reaction conditions
to result in one or more products comprising PBH and DBP, and the
metal bromide with the metal ion in lower oxidation state; (iii)
extracting the one or more products comprising PBH and DBP from the
aqueous medium by extracting with DBP as an extraction solvent; and
(iv) hydrolyzing the DBP with water to form the PBH.
[0439] It is to be understood that in all the aspects and
embodiments provided herein, the anode electrolyte withdrawn from
the electrochemical cell and/or the metal chloride with metal ion
in the higher oxidation state withdrawn from the oxychlorination
reaction, comprise both the metal chloride with the metal ion in
the lower oxidation state as well as the metal chloride with the
metal ion in the higher oxidation state (e.g. CuCl.sub.x).
Similarly, it is to be understood that in all the aspects and
embodiments provided herein, the anode electrolyte withdrawn from
the electrochemical cell and/or the metal bromide with metal ion in
the higher oxidation state withdrawn from the oxybromination
reaction, comprise both the metal bromide with the metal ion in the
lower oxidation state as well as the metal bromide with the metal
ion in the higher oxidation state (e.g. CuBr.sub.z). The integer z
herein and in the figures can be anywhere between 1-4 depending on
the valency of the metal ion. For example, z is between 1-2 for Cl
and Br, such as for example only, CuCl and CuCl.sub.2 or CuBr and
CuBr.sub.2.
[0440] In some embodiments, the method further includes after
extraction, transferring aqueous medium comprising the metal halide
with metal ions in the higher oxidation state and the lower
oxidation state to the oxyhalogenating reaction/reactor; to the
hydrolysis reaction/reactor; to the halogenation reaction/reactor;
and/or to the electrochemical reaction/cell.
[0441] In some embodiments, the temperature and the residence time
in the hydrolysis reaction/reactor may be different from the one in
the halogenation reaction/reactor. For example, in some
embodiments, the hydrolysis reaction may be run at a lower
temperature than the halogenation reaction. Also, in some
embodiments, the residence time in the hydrolysis reaction may be
longer than that in the halogenation reaction. The extraction
method may be such that once the one or more products comprising
DCP and PCH or DBP and PBH are extracted from the aqueous medium
using the DCP or the DBP as an extraction solvent, the organics are
transferred to the hydrolysis reaction; the aqueous stream
comprising metal halide with metal ions in the higher oxidation
state and the lower oxidation state is added back to the hydrolysis
reaction; and the reaction is run at lower temperature and longer
residence time so that the DCP is hydrolyzed to the PCH or the DBP
is hydrolyzed to the PBH. This may avoid more DCP or more DBP being
formed and/or more PCH or more PBH decomposing to form other side
products in the halogenation reaction.
[0442] In some embodiments of the above noted aspect, the method
further includes (v) transferring the organic medium comprising PCH
and DCP or PBH and DBP (DCP or DBP remaining if any, after the
hydrolyis) from the hydrolyzing step to epoxidation; and (vi)
epoxidizing the PCH or the PBH with a base to form PO in the
presence of the DCP or DBP, respectively (described in detail
herein).
[0443] In some embodiments of the foregoing aspect and embodiments,
the one or more products further comprise isopropanol and/or
isopropyl halide. In some embodiments of the foregoing aspect and
embodiments, the method further comprises converting the
isopropanol and/or the isopropyl halide back to the propylene, DCP,
and/or PCH (when halide is Cl). In some embodiments, other
isopropanol and/or other isopropyl chloride (waste streams from
other processes or sources) may be used in this process and are
converted to more valuable propylene, DCP, and/or PCH.
[0444] The selectivity and the STY of the PCH or the PBH formed by
the methods and systems provided herein, have been described
earlier.
Reaction Conditions for the Hydrolysis of the DCP to the PCH or the
DBP to the PBH
[0445] In the above noted aspects, a recirculating stream of the
DCP or the DBP hydrolyzes to the PCH or the PBH, respectively, in
the hydrolysis reactor by addition of reactants and removal of
products. Some reaction conditions such as, but not limited to, low
temperature and longer residence time have been described above. In
some embodiments, the hydrolysis reactor runs at different pressure
and temperature conditions than the halogenation reactor and that
drives the hydrolysis reaction. For example, in some embodiments,
since there is no propylene in the hydrolysis reactor, it can be
run at a lower pressure and/or longer residence time than the
halogenation reactor, thereby expediting the hydrolysis reaction.
In some embodiments, the temperature of the hydrolysis
reaction/reactor is between 20.degree. C.-200.degree. C. or between
90.degree. C.-160.degree. C. In some embodiments, the residence
time in the hydrolysis reaction/reactor is less than two hrs; or
less than one hr; or between 1 sec-2 hrs; or between 1 min-1 hr. In
some embodiments, the hydrolysis of the DCP to the PCH or the DBP
to the PBH in the hydrolysis reactor may be catalyzed by the
presence of a heterogenous catalyst, such as, but not limited to, a
noble metal. The noble metals have been described herein for the
formation of the PCH or the PBH and can be used in the hydrolysis
of the DCP to the PCH or the DBP to the PBH as well.
[0446] In some embodiments, the reaction conditions for the
hydrolysis comprises concentration of the metal halide with metal
ion in the higher oxidation state (for example only CuCl.sub.2 or
CuBr.sub.2) of between about 1-3M.
[0447] In some embodiments of the above noted aspects, when the
metal chloride is copper chloride (CuCl as the metal chloride with
metal ions in the lower oxidation state and CuCl.sub.2 as the metal
chloride with metal ions in the higher oxidation state), the
hydrolysis of the DCP to the PCH may be carried out in presence of
copper hydroxychloride species of stoichiometry
Cu.sub.xCl.sub.y(OH).sub.(2x-y). The formation of the copper
hydroxychloride species of stoichiometry
Cu.sub.xCl.sub.y(OH).sub.(2x-y) via the oxychlorination reaction
(or copper hydroxybromide via oxybromination) has been described
above. In some embodiments, the copper hydroxychloride species of
stoichiometry Cu.sub.xCl.sub.y(OH).sub.(2x-y), such as, e.g.
Cu(OH)Cl, can serve as a base consuming HCl via:
Cu(OH)Cl+HCl.fwdarw.CuCl.sub.2+H.sub.2O
[0448] In some embodiments, the Cu(OH)Cl may serve as an active
site to form the PCH directly from the DCP as shown in reaction
below:
Cu(OH)Cl+ClCH.sub.2CH(Cl)CH.sub.3.fwdarw.ClCH.sub.2CH(OH)CH.sub.3+CuCl.s-
ub.2
[0449] Without being limited by any theory, it is contemplated that
either or both of the reactions may occur in the presence of copper
hydroxychloride species of stoichiometry
Cu.sub.xCl.sub.y(OH).sub.(2x-y), such as, e.g. Cu(OH)Cl. The
reactions noted above equally apply to the bromide system as
well.
Forming the PO from the PCH or the PBH
[0450] In some embodiments of the foregoing aspect and embodiments,
the methods further comprise reacting the PCH or the PBH with a
base to form the PO. Various process configurations that lead to
the epoxidation step have been described above and are illustrated
in the figures herein.
[0451] Typically, the conversion of the PCH to the PO is a
ring-closing reaction whereby the chlorohydrin molecule may be
combined in a near stoichiometric ratio with a base such as e.g.
sodium hydroxide (NaOH) or lime (CaO). The products are PO, the
chloride salt of the base (e.g. NaCl or CaCl.sub.2 respectively)
and water. Because the PO may be a reactive molecule, it may need
to be removed from the reaction media quickly. Typically, the short
residence time requirement may be achieved by steam stripping the
PO as it is formed in the reactor. However, because the PCH feeding
the reactor may be diluted with a large excess of water due to
upstream reaction selectivity considerations (described further
herein below), the steam demand for PO stripping may be very
high.
[0452] In some aspects noted above, there are provided methods and
systems comprising reacting the PCH with a base to form PO in
presence of DCP or the methods and systems comprise reacting the
solution of the PCH and the DCP with a base to form PO. In these
aspects, the DCP is not separated from the PCH after hydrolysis and
the solution is directly subjected to epoxidation. In such
embodiments, the separation of the DCP and the PCH step (before
and/or after hydrolysis step) may be combined with the epoxidation
step such that when the base is added into the epoxidation reactor,
the base reacts with the PCH to form the PO, which may leave the
reactor as a vapor. In this process, some DCP may be converted to
the PCH which would also form the PO. In some embodiments, the
residual levels of un-reacted PCH may leave the reactor in the DCP
extraction solvent (DCP as an extraction solvent has been described
before) and return to the process where appropriate.
[0453] In some aspects noted above, there are provided methods and
systems comprising reacting the PBH with a base to form PO in
presence of DBP or the methods and systems comprise reacting the
solution of the PBH and the DBP with a base to form PO. In these
aspects, the DBP is not separated from the PBH after hydrolysis and
the solution is directly subjected to epoxidation. In such
embodiments, the separation of the DBP and the PBH step (before
and/or after hydrolysis step) may be combined with the epoxidation
step such that when the base is added into the epoxidation reactor,
the base reacts with the PBH to form the PO, which may leave the
reactor as a vapor. In this process, some DBP may be converted to
the PBH which would also form the PO. In some embodiments, the
residual levels of un-reacted PBH may leave the reactor in the DBP
extraction solvent (DBP as an extraction solvent has been described
before) and return to the process where appropriate.
[0454] The methods and systems provided herein for converting the
PCH to the PO in the presence of the DCP (where the mol % of the
DCP may be equal to or greater than the mol % of the PCH) has a
number of advantages (similar advantages apply for the bromide
system). First, it may obviate the need for separation of the PCH
from the DCP prior to the epoxidation. To maintain high selectivity
of the PCH during the hydrolysis reaction, the DCP level may be in
excess relative to the converted amount of the DCP as described
above. The PCH may be separated from the DCP via a typical
separation operation. If PCH were the lighter (lower boiling)
component, distillation would be an option. However, because PCH is
the heavier component, separation by distillation may require the
excess DCP be removed in the overhead of the column which in turn
may lead to prohibitive steam demand. Alternative separation
technologies, such as absorption or selective permeation, may be
equally prohibitive due to either capital equipment costs or
operating costs. Second, because the PO may also be soluble in the
DCP, the reactor may not require steam stripping inside the
reactor. The PO can be removed from the reactor in the DCP phase if
desired and separated downstream. Third, additional side reactions
may be minimized because PO may react much more slowly in the
organic (DCP) phase. Finally, the total waste water demand may be
significantly reduced because the water leaving the reactor would
primarily be that which came in with the caustic (and low levels of
soluble water with the organic phase). In some embodiments, when
using NaOH as the base for the PO formation, the resulting aqueous
solution may be concentrated enough in NaCl to merit removing the
waste organics and using the brine back in the electrochemical
cell.
[0455] In addition to the advantages described above, the
conversion of the PCH to the PO in the presence of DCP may also
allow for process options that minimize by-product losses, such as,
a single aqueous phase reactor that contains both reactants and
products; minimizing by-product formation by running the reactor
with a short residence time; step-wise addition of the NaOH; and
recycling of the product stream back to the reactor.
[0456] The step-wise addition of NaOH (e.g. along a length of pipe
if the reaction is done in a continuous system) may reduce the
by-product formation because the aqueous salt solutions resulting
from the early additions may dilute the later additions. In this
way, the caustic concentrations within the aqueous phase can be
more easily managed along the reactor length. The recycling of the
aqueous product stream back to the reactor inlet may also minimize
the NaOH concentration in the aqueous phase. The recycling option
has other advantages too. For example, the recycle stream may
return salt-rich brine to the reactor. The presence of the salt may
minimize the solubility of the PO in the aqueous phase which may
improve reactor selectivity. Further, the highly concentrated salt
may be advantageous because the resulting brine stream exiting the
epoxidation unit may serve as a feedstock for electrolysis cells
after removal of the residual, soluble organics. Furthermore, the
recycle of reactor outlet may allow the reactor to run in such a
way as to produce a high salt concentration outlet stream without
having to feed a high concentration NaOH stream directly to the
reactor. The other advantages of the high salt concentration outlet
stream have also been described further herein.
[0457] In some embodiments of the foregoing aspect and embodiments,
the base is an alkali metal hydroxide, such as e.g. NaOH or alkali
metal oxide; alkaline earth metal hydroxide or oxide, such as e.g.
Ca(OH).sub.2 or CaO; or metal hydroxide chloride or bromide (for
example only, M.sub.x.sup.n+X.sub.y(OH).sub.(nx-y)). In some
embodiments of the foregoing aspect and embodiments, metal in the
metal hydroxychloride or metal hydroxybromide is same as metal in
the metal chloride or the metal bromide. In some embodiments of the
foregoing aspect and embodiments, the method further comprises
forming the metal hydroxychloride by oxychlorinating the metal
chloride with the metal ion in the lower oxidation state to the
higher oxidation state in presence of water and oxygen (as
explained above; metal hydroxybromide applies in the same way).
[0458] Typically, in chlorohydrin processes for the production of
propylene oxide, the NaOH may be combined and reacted with an
approximately 4-5 wt % solution of propylene chlorohydrins. The
propylene chlorohydrins are a mix of 1-chloro-2-propanol
(approximately 85-90%) and 2-chloro-1-propanol (approximately
10-15%). The propylene oxide formation reaction is shown as
below:
C.sub.3H.sub.6(OH)Cl+NaOH.fwdarw.C.sub.3H.sub.6O(PO)+NaCl+H.sub.2O
[0459] Propylene oxide may be rapidly stripped from the solution in
either a vacuum stripper or steam stripper. A primary disadvantage
of the process may be the generation of a dilute NaCl brine stream
with about 3-6 wt % NaCl with flow rate exceeding 40-45 tonnes of
brine per tonne of propylene oxide. The large amount of dilute
brine may result in large amount of waste water. The reason for the
large volume of water may be that the reactor producing the
propylene chlorohydrins must operate at dilute concentrations of
about 4-5 wt % propylene chlorohydrin in order to achieve high
selectivity.
[0460] Applicants have discovered that using the methods of the
invention that produce PCH or PBH in high selectivity and high STY,
the amount of dilute brine generated after the PO formation can be
substantially reduced. In some embodiments of the foregoing aspect
and embodiments, the reaction forms between about 5-40 tonnes of
brine per tonne of PO which is substantially less brine compared to
the brine generated in a typical PO reaction.
[0461] In one aspect, there is provided a method to form propylene
oxide (PO), comprising halogenating propylene in an aqueous medium
comprising metal halide with metal ion in higher oxidation state
and salt to result in one or more products comprising between about
5-99.9 wt % PCH or PBH, and the metal halide with the metal ion in
lower oxidation state; and reacting the PCH or PBH with a base to
form PO and brine in water, wherein the reaction forms between
about 5-42 tonnes of brine per tonne of PO.
[0462] In one aspect, there is provided a method to form propylene
oxide (PO), comprising chlorinating propylene in an aqueous medium
comprising metal chloride with metal ion in higher oxidation state
and salt to result in one or more products comprising DCP and PCH,
and the metal chloride with the metal ion in lower oxidation state;
extracting the DCP and the PCH with re-circulating DCP from the
same process and/or the other DCP; hydrolyzing the DCP in the
mixture of the DCP and the PCH to the PCH; and reacting the PCH in
presence of remaining DCP with a base to form PO and brine in
water. In one aspect, there is provided a method to form propylene
oxide (PO), comprising brominating propylene in an aqueous medium
comprising metal bromide with metal ion in higher oxidation state
and salt to result in one or more products comprising DBP and PBH,
and the metal bromide with the metal ion in lower oxidation state;
extracting the DBP and the PBH with re-circulating DBP from the
same process and/or the other DBP; hydrolyzing the DBP in the
mixture of the DBP and the PBH to the PBH; and reacting the PBH in
presence of remaining DBP with a base to form PO and brine in
water.
[0463] In some embodiments of the foregoing aspect, the reaction
forms between about 5-42 or about 5-40 tonnes of brine per tonne of
PO. In some embodiments of the foregoing aspect, the selectivity of
the PCH or PBH formed (after chlorination or bromination and
hydrolysis) is between about 10-99.9 wt %. In some embodiments of
the foregoing aspect and embodiments, the base is between about
5-35 wt % or between about 8-15 wt %. The bases have been described
herein and include without limitation, the alkali metal hydroxide
e.g. sodium hydroxide or potassium hydroxide; alkaline earth metal
hydroxide e.g. calcium hydroxide or oxide e.g. CaO or MgO; or metal
hydroxide chloride. The PO formation has been illustrated in FIGS.
30-35.
[0464] In some embodiments of the aforementioned aspects, the PO
formed is between about 5-50 wt %; or between about 5-40 wt %; or
between about 5-30 wt %; or between about 5-20 wt %; or between
about 5-10 wt %; or between about 10-50 wt %; or between about
10-40 wt %; or between about 10-30 wt %; or between about 10-20 wt
%; or between about 20-50 wt %; or between about 20-40 wt %; or
between about 20-30 wt %; or between about 30-50 wt %; or between
about 30-40 wt %; or between about 40-50 wt %. In some embodiments
of the aspects and embodiments provided herein, the PO formed is
between about 1-25 wt %; or between about 2-20 wt %; or between
about 3-15 wt %.
[0465] In some embodiments of the aspect and embodiments provided
herein, the reaction forms between about 5-42 tonnes of brine per
tonne of PO; or between about 5-40 tonnes of brine per tonne of PO;
or between about 5-35 tonnes of brine per tonne of PO; or between
about 5-30 tonnes of brine per tonne of PO; or between about 5-25
tonnes of brine per tonne of PO; or between about 5-20 tonnes of
brine per tonne of PO; or between about 5-10 tonnes of brine per
tonne of PO. In some embodiments of the aspect and embodiments
provided herein, the reaction forms between about 3-40 tonnes of
brine per tonne of PO; or between about 4-20 tonnes of brine per
tonne of PO; or between about 4-12 tonnes of brine per tonne of
PO.
[0466] In some embodiments of the aspect and embodiments provided
herein, the base is between about 5-50 wt %; or between about 5-40
wt %; or between about 5-30 wt %; or between about 5-20 wt %; or
between about 5-10 wt %; or between about 10-50 wt %; or between
about 10-40 wt %; or between about 10-30 wt %; or between about
10-20 wt %; or between about 20-50 wt %; or between about 20-40 wt
%; or between about 20-30 wt %; or between about 30-50 wt %; or
between about 30-40 wt %; or between about 40-50 wt %; or between
about 8-15 wt %; or between about 10-15 wt %; or between about
12-15 wt %; or between about 14-15 wt %; or between about 8-10 wt
%; or between about 8-12 wt %. In some embodiments of the aspect
and embodiments provided herein, the base is between about 5-38 wt
%; or between about 7-33 wt %; or between about 8-20 wt %.
[0467] In some embodiments of the foregoing aspects and embodiment,
the method further comprises transferring aqueous medium comprising
the metal halide with the metal ion in the lower oxidation state
and the salt to an anode electrolyte in contact with an anode in an
electrochemical cell and oxidizing the metal ion from the lower
oxidation state to the higher oxidation state at the anode.
[0468] In some embodiments of the foregoing aspects and embodiment,
the method further comprises transferring the aqueous medium
comprising the metal halide with the metal ion in the lower
oxidation state and the salt to an oxyhalogenation reaction and
oxidizing the metal ion from the lower oxidation state to the
higher oxidation state in the presence of the oxidant.
[0469] In some embodiments of the foregoing aspect and embodiments,
the one or more products further comprise HCl or HBr. In some
embodiments of the foregoing aspect and embodiments, the method
further comprises after the halogenation step, oxyhalogenating the
metal halide with the metal ion in the lower oxidation state to the
metal ion in the higher oxidation state in presence of the HCl or
HBr and/or oxygen, or hydrogen peroxide.
[0470] In some embodiments of the foregoing aspect and embodiments,
the method further comprises recirculating the metal halide in the
higher oxidation state back to the halogenating step.
[0471] In the methods and systems provided herein, the separation
and/or purification may include one or more of the separation and
purification of the organic products from the metal ion solution
and/or the separation and purification of the organic products from
each other, to improve the overall yield of the PCH or PBH, improve
selectivity of the PCH or PBH, improve purity of the PCH or PBH,
improve efficiency of the systems, improve ease of use of the
solutions in the overall process, improve reuse of the metal
solution, and/or to improve the overall economics of the
process.
[0472] In some embodiments, the solution containing the one or more
products and the metal halide may be subjected to a washing step
which may include rinsing with an organic solvent or passing the
organic product through a column to remove the metal ions. In some
embodiments, the organic products may be purified by
distillation.
[0473] In one aspect, there are provided systems, comprising
reactors configured to carry out the reactions of the preceding
aspects and embodiments.
[0474] The systems provided herein include one or more reactors
that carry out the halogenation reaction; the hydrolysis reaction;
the oxyhalogenation reaction; and the epoxidation reaction. The
"reactor" as used herein is any vessel or unit in which the
reaction provided herein is carried out. For example, the
halogenation reactor is configured to contact the metal halide
solution with the propylene to form the one or more products. The
reactor may be any means for contacting the metal halide with the
propylene. Such means or such reactor are well known in the art and
include, but not limited to, pipe, column, duct, tank, series of
tanks, container, tower, conduit, and the like. The reactor may be
equipped with one or more of controllers to control temperature
sensor, pressure sensor, control mechanisms, inert gas injector,
etc. to monitor, control, and/or facilitate the reaction.
[0475] In some embodiments, the reactor system may be a series of
reactors connected to each other. For example, to increase the
yield of the PCH or the PBH, the halogenation mixture may be kept
either in the same reaction vessel (or reactor), or in a second
reaction vessel (hydrolysis reactor) that does not contain
additional propylene. The second reaction vessel may be a stirred
tank. The stirring may increase the mass transfer rate of the PCH
and/or the DCP (or PBH and/or the DBP) into the aqueous medium
accelerating the reaction to the PCH.
[0476] The reactor configuration includes, but is not limited to,
design parameters of the reactor such as, e.g. length/diameter
ratio, flow rates of the liquid(s) and gas(es), material of
construction, packing material and type of reactor such as, packed
column, bubble column, or trickle-bed reactor, or combinations
thereof. In some embodiments, the systems may include one reactor
or a series of multiple reactors connected to each other or
operating separately. The reactor may be a packed bed such as, but
not limited to, a hollow tube, pipe, column or other vessel filled
with packing material. The reactor may be a spray reactor. The
reactor may be a trickle-bed reactor. The reactor may be a bubble
column. In some embodiments, the packed bed reactor includes a
reactor configured such that the aqueous medium containing the
metal ions and the propylene flow counter-currently in the reactor
or includes the reactor where the aqueous medium containing the
metal ions flows in from the top of the reactor and the propylene
gas is pressured in from the bottom. In some embodiments, in the
latter case, the propylene may be fed in such a way that only when
the propylene gets consumed, that more propylene flows into the
reactor. The trickle-bed reactor includes a reactor where the
aqueous medium containing the metal ions and the propylene flow
co-currently in the reactor.
[0477] In some embodiments, the reactor may be configured for both
the reaction and separation of the products. The processes and
systems described herein may be batch processes or systems or
continuous flow processes or systems.
[0478] Other features of the propylene oxide related methods and
systems may have been described in detail in U.S. application Ser.
No. 15/992,422, filed 30 May 2018, which is incorporated herein by
reference in its entirety. Other features of the bromide methods
and systems to form PO (i.e. using metal bromide) may have been
described in detail in U.S. Provisional Application No. 62/948,459,
filed even date herewith, which is incorporated herein by reference
in its entirety.
[0479] In some embodiments, the yield of the halogenated
hydrocarbon from unsaturated hydrocarbon, e.g. the yield of EDC
from ethylene or yield of DCP from propylene, or dichlorobutene
from butene, using the metal ions is more than 90% or more than 95%
or between 90-95% or between 90-99% or between 90-99.9% by weight.
In some embodiments, the selectivity of the halogenated hydrocarbon
from unsaturated hydrocarbon, e.g. the yield of EDC from ethylene
or yield of DCP from propylene, or dichlorobutene from butene,
using the metal ions is more than 80% or more than 90% or between
80-99% by weight. In some embodiments, the STY (space time yield)
of the halogenated hydrocarbon from unsaturated hydrocarbon, e.g.
the yield of EDC from ethylene or yield of DCP from propylene, or
dichlorobutene from butene, using the metal ions is more than 3 or
more than 4 or more than 5 or between 3-5 or between 3-6 or between
3-8.
[0480] In some embodiments, the metal formed with a higher
oxidation state in the anode electrolyte of the electrochemical
systems of FIGS. 1A, 1B, 2, 3A, 3B, 4A, 4B, 5A, and 5B may be
reacted with saturated hydrocarbons to from corresponding
halohydrocarbons or sulfohydrocarbons based on the anion attached
to the metal. For example, the metal chloride, metal bromide, metal
iodide, or metal sulfate etc. may result in corresponding
chlorohydrocarbons, bromohydrocarbons, iodohydrocarbons, or
sulfohydrocarbons, after the reaction of the saturated hydrocarbons
with the metal halide or metal sulfate. In some embodiments, the
reaction of metal halide or metal sulfate with the saturated
hydrocarbons results in the generation of the above described
products as well as the metal halide or metal sulfate in the lower
oxidation state. The metal ion in the lower oxidation state may
then be re-circulated back to the electrochemical system for the
generation of the metal ion in the higher oxidation state.
[0481] The "saturated hydrocarbon" as used herein, includes a
hydrocarbon with no unsaturated carbon or hydrocarbon. The
hydrocarbon may be linear, branched, or cyclic. For example, the
hydrocarbon may be substituted or unsubstituted alkanes and/or
substituted or unsubstituted cycloalkanes. The hydrocarbons may
have a general formula of an unsubstituted alkane as
C.sub.nH.sub.2n+2 where n is 2-20 or 2-10 or 2-8, or 2-5. In some
embodiments, one or more hydrogens on the alkane or the
cycloalkanes may be further substituted with other functional
groups such as but not limited to, halogen (including chloro,
bromo, iodo, and fluoro), carboxylic acid (--COOH), hydroxyl
(--OH), amines, etc.
[0482] In some embodiments, the saturated hydrocarbon in the
methods and systems provided herein, is of formula III which after
halogenation or sulfonation (including sulfation) results in the
compound of formula IV:
##STR00021##
[0483] wherein, n is 2-10; k is 0-5; and s is 1-5;
[0484] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0485] X is a halogen selected from fluoro, chloro, bromo, and
iodo; --SO.sub.3H; or --OSO.sub.2OH.
[0486] It is to be understood that R substitutent(s) can be on one
carbon atom or on more than 1 carbon atom depending on the number
of R and carbon atoms. For example only, when n is 3 and k is 2,
the substituents R can be on the same carbon atom or on two
different carbon atoms.
[0487] In some embodiments, the saturated hydrocarbon in the
methods and systems provided herein, is of formula III which after
halogenation results in the compound of formula IV:
[0488] wherein, n is 2-10; k is 0-5; and s is 1-5;
[0489] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen, alkyl, and substituted alkyl; and
[0490] X is a halogen selected from chloro, bromo, and iodo.
[0491] In some embodiments, the saturated hydrocarbon in the
methods and systems provided herein, is of formula III which after
halogenation results in the compound of formula IV:
[0492] wherein, n is 2-5; k is 0-3; and s is 1-4;
[0493] R is independently selected from hydrogen, halogen, --COOR',
--OH, and --NR'(R''), where R' and R'' are independently selected
from hydrogen and alkyl; and
[0494] X is a halogen selected from chloro and bromo.
[0495] In some embodiments, the saturated hydrocarbon in the
methods and systems provided herein, is of formula III which after
halogenation results in the compound of formula IV:
[0496] wherein, n is 2-5; k is 0-3; and s is 1-4;
[0497] R is independently selected from hydrogen, halogen, and
--OH, and
[0498] X is a halogen selected from chloro and bromo.
[0499] It is to be understood that when k is more than 1, the
substituents R can be on the same carbon atom or on a different
carbon atoms. Similarly, it is to be understood that when s is more
than 1, the substituents X can be on the same carbon atom or on
different carbon atoms.
[0500] In some embodiments for the above described embodiments of
formula III, k is 0 and s is 1-2. In such embodiments, X is
chloro.
[0501] Examples of substituted or unsubstituted alkanes, e.g. of
formula III, include, but not limited to, methane, ethane,
chloroethane, bromoethane, iodoethane, propane, chloropropane,
hydroxypropane, butane, chlorobutane, hydroxybutane, pentane,
hexane, cyclohexane, cyclopentane, chlorocyclopentane, etc.
[0502] In some embodiments, there are provided methods that include
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting or oxidizing the metal ion from a lower
oxidation state to a higher oxidation state at the anode; and
treating the anode electrolyte comprising the metal ion in the
higher oxidation state with a saturated hydrocarbon. In some
embodiments of the method, the method includes contacting a cathode
with a cathode electrolyte and forming an alkali at the cathode. In
some embodiments of the method, the method includes contacting a
cathode with a cathode electrolyte and forming an alkali and
hydrogen gas at the cathode. In some embodiments of the method, the
method includes contacting a cathode with a cathode electrolyte and
forming hydrogen gas at the cathode. In some embodiments of the
method, the method includes contacting a gas-diffusion cathode with
a cathode electrolyte and forming an alkali at the cathode. In some
embodiments of the method, the method includes contacting a
gas-diffusion cathode with a cathode electrolyte and forming water
at the cathode. In some embodiments, there are provided methods
that include contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; converting the metal ion from a
lower oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte; forming an alkali,
water, and/or hydrogen gas at the cathode; and treating the anode
electrolyte comprising the metal ion in the higher oxidation state
with a saturated hydrocarbon. In some embodiments, there are
provided methods that include contacting an anode with a metal ion
in an anode electrolyte in an anode chamber; converting the metal
ion from a lower oxidation state to a higher oxidation state at the
anode; contacting a gas-diffusion cathode with a cathode
electrolyte; forming an alkali or water at the cathode; and
treating the anode electrolyte comprising the metal ion in the
higher oxidation state with a saturated hydrocarbon. In some
embodiments, the treatment of the saturated hydrocarbon with the
metal ion in the higher oxidation state may be inside the cathode
chamber or outside the cathode chamber. In some embodiments, the
treatment of the metal ion in the higher oxidation state with the
saturated hydrocarbon results in halogenated hydrocarbon or
sulfohydrocarbon, such as, chloro, bromo, iodo, or
sulfohydrocarbons and the metal ion in the lower oxidation state.
In some embodiments, the metal ion in the lower oxidation state is
re-circulated back to the anode chamber. In some embodiments, the
saturated hydrocarbon in the aforementioned embodiments and as
described herein is of formula III (as described herein) or is
C2-C10 alkane or C2-C5 alkane. In some embodiments, the saturated
hydrocarbon in the aforementioned embodiments and as described
herein is, methane. In some embodiments, the saturated hydrocarbon
in the aforementioned embodiments and as described herein is,
ethane. In some embodiments, the saturated hydrocarbon in the
aforementioned embodiments and as described herein is, propane. The
halohydrocarbon formed from such saturated hydrocarbon is of
formula IV (as described herein), e.g., chloromethane,
dichloromethane, chloroethane, dichloroethane, chloropropane,
dichloropropane, etc.
[0503] In some embodiments of the above described methods, the
metal ion used is platinum, palladium, copper, iron, tin, and
chromium. In some embodiments of the above described methods, the
anode does not produce chlorine gas. In some embodiments of the
above described methods, the treatment of the saturated hydrocarbon
with the metal ion in the higher oxidation state does not require
oxygen gas and/or chlorine gas. In some embodiments of the above
described methods, the anode does not produce chlorine gas and the
treatment of the saturated hydrocarbon with the metal ion in the
higher oxidation state does not require oxygen gas and/or chlorine
gas.
[0504] In some embodiments, there are provided systems that include
an anode chamber including an anode in contact with a metal ion in
an anode electrolyte wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state;
and a reactor operably connected to the anode chamber and
configured to react the anode electrolyte comprising the metal ion
in the higher oxidation state with a saturated hydrocarbon. In some
embodiments of the systems, the system includes a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form an alkali at the cathode. In some embodiments
of the systems, the system includes a cathode chamber including a
cathode with a cathode electrolyte wherein the cathode is
configured to form hydrogen gas at the cathode. In some embodiments
of the systems, the system includes a cathode chamber including a
cathode with a cathode electrolyte wherein the cathode is
configured to form an alkali and hydrogen gas at the cathode. In
some embodiments of the systems, the system includes a
gas-diffusion cathode with a cathode electrolyte wherein the
cathode is configured to form an alkali at the cathode. In some
embodiments of the systems, the system includes a gas-diffusion
cathode with a cathode electrolyte wherein the cathode is
configured to form water at the cathode. In some embodiments, there
are provided systems that include an anode chamber including an
anode with a metal ion in an anode electrolyte wherein the anode is
configured to convert the metal ion from a lower oxidation state to
a higher oxidation state in the anode chamber; a cathode chamber
including a cathode with a cathode electrolyte wherein the cathode
is configured to form an alkali, water, and hydrogen gas in the
cathode electrolyte; and a reactor operably connected to the anode
chamber and configured to react the anode electrolyte comprising
the metal ion in the higher oxidation state with saturated
hydrocarbon. In some embodiments, there are provided systems that
include an anode chamber including an anode with a metal ion in an
anode electrolyte wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state
in the anode chamber; a cathode chamber including a gas-diffusion
cathode with a cathode electrolyte wherein the cathode is
configured to form an alkali or water in the cathode electrolyte;
and a reactor operably connected to the anode chamber and
configured to react the anode electrolyte comprising the metal ion
in the higher oxidation state with saturated hydrocarbon. In some
embodiments, the treatment of the saturated hydrocarbon with the
metal ion in the higher oxidation state may be inside the cathode
chamber or outside the cathode chamber. In some embodiments, the
treatment of the metal ion in the higher oxidation state with the
saturated hydrocarbon results in chloro, bromo, iodo, or
sulfohydrocarbons and the metal ion in the lower oxidation state.
In some embodiments, the system is configured to form the metal ion
in the lower oxidation state from the metal ion in the higher
oxidation state with the saturated hydrocarbon and re-circulate the
metal ion in the lower oxidation state back to the anode
chamber.
[0505] In some embodiments of the methods and systems described as
above, the metal ion is a metal ion described herein, such as, but
not limited to, platinum, palladium, copper, iron, tin, or
chromium.
[0506] In some embodiments of the above described systems, the
anode is configured to not produce chlorine gas. In some
embodiments of the above described systems, the reactor configured
to react the saturated hydrocarbon with the metal ion in the higher
oxidation state, is configured to not require oxygen gas and/or
chlorine gas. In some embodiments of the above described methods,
the anode is configured to not produce chlorine gas and the reactor
is configured to not require oxygen gas and/or chlorine gas.
[0507] It is to be understood that the example of the
electrochemical system illustrated in FIG. 8A can be configured for
saturated hydrocarbons by replacing the unsaturated hydrocarbon
with a saturated hydrocarbon. Accordingly, suitable metal ions may
be used such as platinum chloride, palladium chloride, copper
chloride etc.
[0508] In some embodiments, the chlorination of ethane in an
aqueous medium with metal chloride in the higher oxidation state,
results in ethane chloride, ethane dichloride, or combination
thereof. In some embodiments of the methods and systems described
herein, there is a formation of more than 10 wt %; or more than 20
wt %, or more than 30 wt %, or more than 40 wt %, or more than 50
wt %, or more than 60 wt %, or more than 70 wt %, or more than 80
wt %, or more than 90 wt %, or more than 95 wt %, or about 99 wt %,
or between about 10-99 wt %, or between about 10-95 wt %, or
between about 15-95 wt %, or between about 25-95 wt %, or between
about 50-95 wt %, or between about 50-99 wt %, or between about
50-99.9 wt %, or between about 50-99.99 wt % chloroethane, from
ethane. In some embodiments, the remaining weight percentage is of
chloroethanol and/or ethylene dichloride. In some embodiments, no
chloroethanol is formed in the reaction. In some embodiments, less
than 0.001 wt % or less than 0.01 wt % or less than 0.1 wt % or
less than 0.5 wt % or less than 1 wt % or less than 5 wt % or less
than 10 wt % or less than 20 wt % of chloroethanol is formed with
the remaining product in the reaction. In some embodiments, less
than 0.001 wt % or less than 0.01 wt % or less than 0.1 wt % or
less than 0.5 wt % or less than 1 wt % or less than 5 wt % of metal
ion is present in the product. In some embodiments, less than 0.001
wt % or less than 0.01 wt % or less than 0.1 wt % of chloroethanol
and/or metal ion is present in the product.
[0509] In some embodiments, the yield of the halogenated
hydrocarbon from saturated hydrocarbon, e.g. the yield of
chloroethane or EDC from ethane, using the metal ions is more than
90% or more than 95% or between 90-95% or between 90-99% or between
90-99.9% by weight. In some embodiments, the selectivity of the
halogenated hydrocarbon from saturated hydrocarbon, e.g. the yield
of chloroethane or EDC from ethane, using the metal ions is more
than 80% or more than 90% or between 80-99% by weight. In some
embodiments, the STY (space time yield) of the halogenated
hydrocarbon from saturated hydrocarbon is more than 3 or more than
4 or more than 5 or between 3-5 or between 3-6 or between 3-8.
[0510] The "lanthanide halide" or "LAH" as used herein, includes
halide of an element from lanthanide series. The element or the
lanthanide from the lanthanide series is selected from the group
consisting of lanthanum, cerium, praseodymium, neodymium,
promethium, samarium, europium, gadolinium, terbium, dysprosium,
holmium, erbium, thulium, ytterbium, lutetium, and combinations
thereof. Chemically similar elements, scandium and yttrium, often
collectively known as the rare earth elements, are also included in
the lanthanide halides used herein. The lanthanide halide or LAH as
used herein may be one lanthanide halide or may be a combination of
two or more lanthanide halides, where the lanthanide in the one or
more lanthanide halides is as noted above. The lanthanide halide
can be in anhydrous form or in the form of a hydrate.
[0511] Applicants have discovered that the use of the one or more
lanthanide halides significantly improve economics and efficiency
of the electrochemical oxidation reaction as well as the
halogenation reaction. It has been discovered that the use of the
one or more lanthanide halides provide several advantages including
but not limited to, improving the operation parameters such as
solubilitity of the metal halide, conversion per pass, reaction
temperature, reaction pressure, residence time of the reaction
mixture, water removal, and/or optimizing the anolyte composition;
to achieve performance parameters, such as but not limited to,
higher selectivity of the halohydrocarbon, higher space time yield
(STY) of the halohydrocarbon, and/or lower electrochemical cell
voltage.
[0512] Typically, solubility of the anolyte may be driven by the
anolyte composition (including but not limited to, concentration of
the metal halide (both in lower oxidation state and higher
oxidation state of the metal), concentration of the one or more
lanthanide halides, other salt if any, water, etc. and/or
temperature. The use of membranes may limit the temperature in the
electrochemical cell. Water removal and water addition may be
possible at multiple points of the recycling anolyte but active
water removal may be energy intensive and may negatively affect the
energy balance of the system. The compositions may be limited to
ratios that allow solubility at the lowest temperature point.
Therefore, the solubility of the anolyte may limit the range of the
concentrations of the metal halide, the concentrations of the one
or more lanthanide halides, and optionally the concentration of the
salt in the anolyte composition.
[0513] Meanwhile, the selectivity of the halohydrocarbon product
may be affected by the operation parameters such as, temperature
and/or the anolyte composition. The voltage of the electrochemical
cell may also depend on anolyte composition as well. For example,
high salt concentrations/low water content may lead to higher
selectivity of the one or more products albeit higher voltages and
lower solubilities in the electrochemical cell. The higher voltage
and lower solubility may both drive operation cost of the system,
therefore, the need to optimize the anolyte composition to high
selectivity and low voltage is desired. For example only, an
increase in the concentration of the metal halide with metal ion in
the higher oxidation state, e.g. only, CuCl.sub.2 while keeping the
other salt concentrations constant (and in the absence of the
lanthanide halide) may lead to an increased STY and selectivity of
the halohydrocarbon product, e.g. ethylene dichloride, but at the
same time may decrease anolyte solubility and increase the
electrochemical voltage.
[0514] The addition of the one or more lanthanide halides to the
anolyte composition improves one or more of the operation
parameters' window such as, but not limited to, optimizes the
concentration range of the anolyte composition, the solubility of
the metal halide, conversion per pass, reaction temperature,
reaction pressure, residence time of the reaction mixture, and/or
water removal, etc.; to achieve performance parameters, such as but
not limited to, high selectivity of the halohydrocarbon, high space
time yield (STY) of the halohydrocarbon, and/or low electrochemical
voltage. In some embodiments, the one or more lanthanide halides
improve economics and efficiency of the process as compared to when
no lanthanide halide is used.
[0515] In one aspect, there are provided methods comprising
contacting an anode with an anode electrolyte wherein the anode
electrolyte comprises metal halide, one or more lanthanide halides,
and water; contacting cathode with a cathode electrolyte; applying
voltage to the anode and the cathode and oxidizing the metal halide
from a lower oxidation state to a higher oxidation state at the
anode; and reacting an unsaturated hydrocarbon or a saturated
hydrocarbon with the metal halide in the higher oxidation state and
the one or more lanthanide halides in the anode electrolyte, to
result in one or more products comprising halohydrocarbon.
[0516] In one aspect, there is provided a system, comprising an
anode in contact with an anode electrolyte wherein the anode
electrolyte comprises metal halide, one or more lanthanide halides,
and water; and wherein the anode is configured to oxidize the metal
halide from a lower oxidation state to a higher oxidation state; a
cathode in contact with a cathode electrolyte; and a reactor
operably connected to the anode chamber and configured to react the
anode electrolyte comprising the metal halide in the higher
oxidation state and the one or more lanthanide halides with an
unsaturated hydrocarbon or saturated hydrocarbon to result in one
or more products comprising halohydrocarbon. The anode electrolyte
comprising the metal halide with the metal ion in the lower
oxidation state and the LAH is then re-circulated back to the anode
chamber.
[0517] In some embodiments of the aforementioned aspects, the
lanthanide in the lanthanide halide or LAH is selected from the
group consisting of lanthanum, cerium, praseodymium, neodymium,
promethium, samarium, europium, gadolinium, terbium, dysprosium,
holmium, erbium, thulium, ytterbium, lutetium, and combinations
thereof. In some embodiments of the aforementioned aspects, the
lanthanide in the lanthanide halide or LAH is selected from the
group consisting of lanthanum, cerium, praseodymium, neodymium,
promethium, samarium, gadolinium, terbium, dysprosium, holmium,
erbium, thulium, ytterbium, lutetium, and combinations thereof. In
some embodiments of the aforementioned aspects and embodiments, the
lanthanide in the lanthanide halide is selected from the group
consisting of lanthanum, cerium, praseodymium, neodymium,
promethium, samarium, and combinations thereof. In some embodiments
of the aforementioned aspects and embodiments, the lanthanide in
the lanthanide halide is selected from the group consisting of
lanthanum, cerium, terbium, dysprosium, holmium, erbium, thulium,
ytterbium, lutetium, and combinations thereof. In some embodiments
of the aforementioned aspects and embodiments, the lanthanide
halide is cerium halide and/or lanthanum halide.
[0518] In some embodiments of the aforementioned aspects and
embodiments, the lanthanide halide is cerium halide. In some
embodiments of the aforementioned aspects and embodiments, the
lanthanide halide is cerium (III) halide. In some embodiments of
the aforementioned aspects and embodiments, the cerium halide is
CeCl.sub.3.7H.sub.2O or any other hydrate.
[0519] In some embodiments of the aforementioned aspects and
embodiments, the lanthanide halide is lanthanum halide. In some
embodiments of the aforementioned aspects and embodiments, the
lanthanum halide is lanthanum (III) halide. In some embodiments of
the aforementioned aspects and embodiments, the lanthanum halide is
LaCl.sub.3.7H.sub.2O or any other hydrate.
[0520] In some embodiments of the aforementioned aspects and
embodiments, the one or more lanthanide halides, for example only,
the cerium halide in the methods and systems provided herein, is in
concentration range of between about 0.4-10 mol %; or between about
0.4-8 mol %; or between about 0.4-7 mol %; or between about 0.4-6
mol %; or between about 0.4-5 mol %; or between about 0.4-4 mol %;
or between about 0.4-3 mol %; or between about 0.4-2 mol %; or
between about 0.4-1 mol %; or between about 1-10 mol %; or between
about 1-8 mol %; or between about 1-6 mol %; or between about 1-5
mol %; or between about 1-4 mol %; or between about 1-2 mol %; or
between about 2-10 mol %; or between about 2-5 mol %; or between
about 4-10 mol %; or between about 4-8 mol %; or between about 5-10
mol %; or between about 5-8 mol %; or between about 6-10 mol %; or
between about 7-10 mol %; or between about 8-10 mol %.
[0521] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte further comprises salt. In some
embodiments of the aforementioned embodiment, the salt comprises
alkali metal halide and/or alkaline earth metal halide. In some
embodiments of the aforementioned embodiments, the alkali metal
halide is alkali metal chloride or alkaline earth metal halide is
alkaline earth metal chloride. In some embodiments of the
aforementioned embodiments, the alkali metal chloride comprises
sodium chloride, potassium chloride, lithium chloride, or the like.
In some embodiments of the aforementioned embodiments, the alkaline
earth metal chloride comprises beryllium chloride, magnesium
chloride, calcium chloride, strontium chloride, barium chloride, or
the like.
[0522] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises the metal halide with
metal ion in the higher oxidation state in range of about 4-17 mol
%; and the metal halide with metal ion in the lower oxidation state
in range of about 0.5-5 mol %.
[0523] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises the metal halide with
metal ion in the higher oxidation state in range of about 4-17 mol
%; the metal halide with metal ion in the lower oxidation state in
range of about 0.5-5 mol %; and the one or more lanthanide halides
in range of about 0.5-10 mol %.
[0524] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises the metal halide with
metal ion in the higher oxidation state in range of about 4-17 mol
%; the metal halide with metal ion in the lower oxidation state in
range of about 0.5-5 mol %; the salt in range of about 0-10 mol %;
and the one or more lanthanide halides in range of about 0.5-10 mol
%.
[0525] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises the metal halide with
metal ion in the higher oxidation state in range of about 4-17 mol
%; the metal halide with metal ion in the lower oxidation state in
range of about 0.5-5 mol %; the alkali metal halide or alkaline
earth metal halide in range of about 0-10 mol %; and the one or
more lanthanide halides in range of about 0.5-10 mol %.
[0526] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises CuCl.sub.2 in range of
about 4-17 mol %; CuCl in range of about 0.5-5 mol %; sodium
chloride in range of about 0-10 mol %; and cerium or europium
chloride in range of about 0.5-10 mol %.
[0527] In some embodiments of the aforementioned aspects and
embodiments, the anode electrolyte comprises CuCl.sub.2 in range of
about 4-17 mol %; CuCl in range of about 0.5-5 mol %; sodium
chloride in range of about 0-10 mol %; and CeCl.sub.3.7H.sub.2O in
range of about 0.5-10 mol %.
[0528] In the above noted aspects and embodiments, the anode
electrolyte comprises water. In the above noted aspects and
embodiments, the anode electrolyte comprises water in remaining mol
%.
[0529] In some embodiments of the aforementioned aspects and
embodiments, ratio of the one or more lanthanide halides to the
metal halide with metal ion in both lower oxidation state and
higher oxidation state is between about 3:1 to 1:10; or about 2:1
to 1:5.
[0530] In some embodiments of the aforementioned aspects and
embodiments, ratio of the one or more lanthanide halides to the
metal halide with metal ion in lower oxidation state is between
about 10:1 to 1:10; or between about 5:1 to 1:5.
[0531] In some embodiments of the aforementioned aspects and
embodiments, ratio of the one or more lanthanide halides to the
alkali metal halide is between about 100:1 to 1:100; or between
about 50:1 to 1:50; or between about 10:1 to 1:10.
[0532] In some embodiments of the aforementioned aspects and
embodiments, ratio of the one or more lanthanide halides to sodium
chloride is between about 100:1 to 1:100; or between about 50:1 to
1:50; or between about 10:1 to 1:10.
[0533] In some embodiments of the aforementioned aspects and
embodiments, the one or more lanthanide halides result in more than
90% or more than 95% selectivity of the halohydrocarbon.
[0534] In some embodiments of the aforementioned aspects and
embodiments, the one or more lanthanide halides reduce temperature
of the reaction by more than 5.degree. C. or more than 10.degree.
C. with substantially same or higher selectivity and/or space time
yield (STY) of the halohydrocarbon as compared to when no
lanthanide halide is used. In some embodiments of the
aforementioned aspects and embodiments, the one or more lanthanide
halides improve economics and efficiency of the process as compared
to when no lanthanide halide is used.
[0535] In all the above noted aspects, the lanthanide in the one or
more lanthanide halides is any one of the lanthanide described
herein.
[0536] A detailed description of the lanthanide halide methods and
systems has been provided in U.S. application Ser. No. 16/135,357,
filed Sep. 19, 2018, which disclosure is incorporated herein by
reference in its entirety.
[0537] The products, such as, but not limited to, halogenated
hydrocarbon, acid, carbonate, and/or bicarbonate formed by the
methods and systems of the invention are greener than the same
products formed by the methods and systems conventionally known in
the art. There are provided methods to make green halogenated
hydrocarbon, that include contacting an anode with an anode
electrolyte; oxidizing a metal chloride from the lower oxidation
state to a higher oxidation state at the anode; contacting a
cathode with a cathode electrolyte; and halogenating an unsaturated
or saturated hydrocarbon with the metal chloride in the higher
oxidation state to produce a green halogenated hydrocarbon. In some
embodiments, there is provided a green halogenated hydrocarbon
formed by the methods described herein. There are also provided
system that include an anode in contact with an anode electrolyte
wherein the anode is configured to oxidize a metal ion from the
lower oxidation state to a higher oxidation state; a cathode in
contact with a cathode electrolyte; and a reactor operably
connected to the anode chamber and configured to react the metal
ion in the higher oxidation state with an unsaturated or saturated
hydrocarbon to form a green halogenated hydrocarbon.
[0538] The term "greener" or "green" or grammatical equivalent
thereof, as used herein, includes any chemical or product formed by
the methods and systems of the invention that has higher energy
savings or voltage savings as compared to the same chemical or
product formed by the methods known in the art. For example,
chlor-alkali is a process that typically is used to make chlorine
gas, which chlorine gas is then used to chlorinate ethylene to form
EDC. The amount of energy required to make EDC from the
chlor-alkali process is higher than the amount of energy required
to make EDC from the metal oxidation process of the invention.
Therefore, the EDC produced by the methods and systems of the
invention is greener than the EDC produced by the chlor-alkali
process. Such savings in energy is illustrated in FIG. 8C which
illustrates the activation barriers for carrying out the methods of
the invention compared to the activation barriers for the
chlor-alkali process.
[0539] As illustrated in FIG. 8C, a comparison is made between the
energy required to make EDC from the chlor-alkali process and the
energy required to make the EDC from the methods and systems of the
invention. The process of making EDC is illustrated in two parts.
An electrochemistry part, where the copper oxidation takes place in
System 1 and System 2 of the invention compared to chlorine
generation taking place in the chlor-alkali process. A catalysis
part, where copper (II) chloride (generated by electrochemistry)
chlorinates ethylene in System 1 and 2 and chlorine gas (generated
by the chlor-alkali process) chlorinates ethylene (conventionally
known) to form EDC. In System 1, the electrochemical reaction is
carried out in the absence of ligand and in System 2, the
electrochemical reaction is carried out in the presence of the
ligand. In System 1, System 2, and the chlor-alkali process, the
cathode is a hydrogen gas producing cathode and the current density
for the electrochemical reaction is 300 mA/cm.sup.2. As illustrated
in FIG. 8C, for the electrochemical reaction, there is an energy
saving of more than 125 kJ/mol for System 1 over chlor-alkali
process and energy savings of more than 225 kJ/mol for System 2
over the chlor-alkali process. Therefore, there can be an energy
savings of up to 300 kJ/mol; or up to 250 kJ/mol; or between 50-300
kJ/mol; or between 50-250 kJ/mol; or between 100-250 kJ/mol; or
between 100-200 kJ/mol, to make the green halogenated hydrocarbon,
such as, but not limited to, EDC, by methods and systems of the
invention as compared to conventional process such as chlor-alkali
process to make EDC. This converts to a saving of more than 1
megawatthour/ton of EDC or between 1-21 megawatthour/ton of EDC for
Systems 1 and 2 compared to the chlor-alkali process. It also
correlates to the voltage saving of more than 1V or between 1-2V
(1V.times.2 electrons is approx. 200 kJ/mol) as compared to the
chlor-alkali process.
[0540] As also illustrated in FIG. 8C, the catalyst part of the
reaction has a theoretical low barrier for each System 1 and 2 and
a high barrier for the two Systems 1 and 2. The catalyst reaction
in System 1 and System 2 can happen at the point of low barrier or
at the point of high barrier or anywhere in between, depending on
conditions, such as, but not limited to, concentration, size of the
reactor, flow rates etc. Even if there is some energy input for the
catalysis reaction in System 1 and 2, it will be offset by the
significant energy saving in the electrochemical reaction such that
there is a net energy saving of up to 100 kJ/mol; or more than 100
kJ/mol; or between 50-100 kJ/mol; or between 0-100 kJ/mol. This
converts to up to or more than 1 megawatthr/ton of EDC or voltage
saving of 0-1V or more than 1V; or between 1-2V as compared to
chlor-alkali process. It is to be understood that the chlor-alkali
process, System 1 and System 2 are all carried out in the aqueous
medium. The electrochemical cell or the catalysis system running on
an organic solvent (e.g., with some or all of the water from
electrochemical cell removed by azeotropic distillation) would
require even higher energy than the conventional method and would
not be yielding a green halogenated hydrocarbon.
[0541] Also further illustrated in FIG. 8C, is the savings in
energy in System 2 which is with the use of the ligand as compared
to System 1 which is without the use of the ligand.
[0542] Accordingly, there are provided methods to make green
halogenated hydrocarbon, that include contacting an anode with an
anode electrolyte; oxidizing a metal chloride from the lower
oxidation state to a higher oxidation state at the anode;
contacting a cathode with a cathode electrolyte; and halogenating
an unsaturated or saturated hydrocarbon with the metal chloride in
the higher oxidation state to produce a green halogenated
hydrocarbon wherein the method results in net energy saving of more
than 100 kJ/mol or more than 150 kJ/mol or more than 200 kJ/mol or
between 100-250 kJ/mol or between 50-100 kJ/mol or between 0-100
kJ/mol or the method results in the voltage savings of more than 1V
or between 0-1V or between 1-2V or between 0-2V. There are also
provided system that include an anode in contact with an anode
electrolyte wherein the anode is configured to oxidize a metal ion
from the lower oxidation state to a higher oxidation state; a
cathode in contact with a cathode electrolyte; and a reactor
operably connected to the anode chamber and configured to react the
metal ion in the higher oxidation state with an unsaturated or
saturated hydrocarbon to form a green halogenated hydrocarbon
wherein the system results in net energy saving of more than 100
kJ/mol or more than 150 kJ/mol or more than 200 kJ/mol or between
100-250 kJ/mol or between 50-100 kJ/mol or between 0-100 kJ/mol or
the system results in the voltage savings of more than 1V or
between 0-1V or between 1-2V or between 0-2V.
[0543] All the electrochemical systems and methods described herein
are carried out in more than 5 wt % water or more than 6 wt % water
or aqueous medium. In one aspect, the methods and systems provide
an advantage of conducting the metal oxidation reaction in the
electrochemical cell and reduction reaction outside the cell, all
in an aqueous medium. Applicants surprisingly and unexpectedly
found that the use of aqueous medium, in the halogenations or
sulfonation of the unsaturated or saturated hydrocarbon or hydrogen
gas, not only resulted in high yield and selectivity of the product
(shown in examples herein) but also resulted in the generation of
the reduced metal ion with lower oxidation state in the aqueous
medium which could be re-circulated back to the electrochemical
system. In some embodiments, since the electrochemical cell runs
efficiently in the aqueous medium, no removal or minimal removal of
water (such as through azeotropic distillation) is required from
the anode electrolyte containing the metal ion in the higher
oxidation state which is reacted with the unsaturated or saturated
hydrocarbon or hydrogen gas in the aqueous medium. Therefore, the
use of the aqueous medium in both the electrochemical cell and the
catalysis system provides efficient and less energy intensive
integrated systems and methods of the invention.
[0544] Accordingly in some embodiments, there is provided a method
including contacting an anode with an anode electrolyte wherein the
anode electrolyte comprises metal ion, oxidizing the metal ion from
a lower oxidation state to a higher oxidation state at the anode,
contacting a cathode with a cathode electrolyte, and reacting an
unsaturated or saturated hydrocarbon with the anode electrolyte
comprising the metal ion in the higher oxidation state in an
aqueous medium wherein the aqueous medium comprises more than 5 wt
% water or more than 5.5 wt % or more than 6 wt % or between 5-90
wt % or between 5-95 wt % or between 5-99 wt % water or between
5.5-90 wt % or between 5.5-95 wt % or between 5.5-99 wt % water or
between 6-90 wt % or between 6-95 wt % or between 6-99 wt % water.
In some embodiments, there is provided a method including
contacting an anode with an anode electrolyte wherein the anode
electrolyte comprises metal ion, oxidizing a metal halide or a
metal sulfate from the lower oxidation state to a higher oxidation
state at the anode, contacting a cathode with a cathode
electrolyte, and halogenating or sulfonating an unsaturated or
saturated hydrocarbon with the metal halide or a metal sulfate in
the higher oxidation state in an aqueous medium wherein the aqueous
medium comprises more than 5 wt % or more than 5.5 wt % or more
than 6 wt % or between 5-90 wt % or between 5-95 wt % or between
5-99 wt % water or between 5.5-90 wt % or between 5.5-95 wt % or
between 5.5-99 wt % water or between 6-90 wt % or between 6-95 wt %
or between 6-99 wt % water. The unsaturated hydrocarbons (such as
formula I), saturated hydrocarbons (such as formula III), the
halogenated hydrocarbons (such as formula II and IV), the metal
ions, etc. have all been described in detail herein.
[0545] In some embodiments, there is provided a method including
contacting an anode with an anode electrolyte, oxidizing a metal
halide or a metal sulfate from the lower oxidation state to a
higher oxidation state at the anode, contacting a cathode with a
cathode electrolyte, and contacting the metal halide or a metal
sulfate in the higher oxidation state with hydrogen gas in an
aqueous medium to form an acid, such as, hydrochloric acid or
sulfuric acid wherein the aqueous medium comprises more than 5 wt %
water or more than 5.5 wt % or more than 6 wt % or between 5-90 wt
% or between 5-95 wt % or between 5-99 wt % water or between 5.5-90
wt % or between 5.5-95 wt % or between 5.5-99 wt % water or between
6-90 wt % or between 6-95 wt % or between 6-99 wt % water. In some
embodiments, the cathode produces hydroxide ions.
[0546] In some embodiments of the above described methods, the
cathode produces water, alkali, and/or hydrogen gas. In some
embodiments of the above described methods, the cathode is an ODC
producing water. In some embodiments of the above described
methods, the cathode is an ODC producing alkali. In some
embodiments of the above described methods, the cathode produces
hydrogen gas. In some embodiments of the above described methods,
the cathode is an oxygen depolarizing cathode that reduces oxygen
and water to hydroxide ions; the cathode is a hydrogen gas
producing cathode that reduces water to hydrogen gas and hydroxide
ions; the cathode is a hydrogen gas producing cathode that reduces
hydrochloric acid to hydrogen gas; or the cathode is an oxygen
depolarizing cathode that reacts hydrochloric acid and oxygen gas
to form water.
[0547] In some embodiments of the above described methods, the
metal ion is any metal ion described herein. In some embodiments of
the above described methods, the metal ion is selected from the
group consisting of iron, chromium, copper, tin, silver, cobalt,
uranium, lead, mercury, vanadium, bismuth, titanium, ruthenium,
osmium, europium, zinc, cadmium, gold, nickel, palladium, platinum,
rhodium, iridium, manganese, technetium, rhenium, molybdenum,
tungsten, niobium, tantalum, zirconium, hafnium, and combination
thereof. In some embodiments, the metal ion is selected from the
group consisting of iron, chromium, copper, and tin. In some
embodiments, the metal ion is copper. In some embodiments, the
lower oxidation state of the metal ion is 1+, 2+, 3+, 4+, or 5+. In
some embodiments, the higher oxidation state of the metal ion is
2+, 3+, 4+, 5+, or 6+.
[0548] In some embodiments, the method further includes
recirculating at least a portion of the metal ion in the lower
oxidation state back to the electrochemical cell. In some
embodiments, the method does not conduct azeotropic distillation of
the water before reacting the metal ion in the higher oxidation
state with the unsaturated or saturated hydrocarbon.
[0549] In some embodiments, the above described methods do not
produce chlorine gas at the anode. In some embodiments, the above
described methods do not require oxygen gas and/or chlorine gas for
the chlorination of unsaturated or saturated hydrocarbon to
halogenated hydrocarbon.
[0550] In some embodiments, there is provided a system, comprising
an anode in contact with an anode electrolyte comprising metal ion
wherein the anode is configured to oxidize the metal ion from the
lower oxidation state to a higher oxidation state; a cathode in
contact with a cathode electrolyte; and a reactor operably
connected to the anode chamber and configured to react the anode
electrolyte comprising the metal ion in the higher oxidation state
with an unsaturated hydrocarbon or saturated hydrocarbon in an
aqueous medium wherein the aqueous medium comprises more than 5 wt
% water or more than 5.5 wt % or more than 6 wt % or between 5-90
wt % or between 5-95 wt % or between 5-99 wt % water or between
5.5-90 wt % or between 5.5-95 wt % or between 5.5-99 wt % water or
between 6-90 wt % or between 6-95 wt % or between 6-99 wt % water.
In some embodiments, there is provided a system including an anode
in contact with an anode electrolyte and configured to oxidize a
metal halide or a metal sulfate from the lower oxidation state to a
higher oxidation state at the anode, a cathode in contact with a
cathode electrolyte, and a reactor operably connected to the anode
chamber and configured to halogenate or sulfonate an unsaturated or
saturated hydrocarbon with the metal halide or a metal sulfate in
the higher oxidation state in an aqueous medium wherein the aqueous
medium comprises more than 5 wt % water or more than 5.5 wt % or
more than 6 wt % or between 5-90 wt % or between 5-95 wt % or
between 5-99 wt % water or between 5.5-90 wt % or between 5.5-95 wt
% or between 5.5-99 wt % water or between 6-90 wt % or between 6-95
wt % or between 6-99 wt % water.
[0551] In some embodiments, there is provided a system including an
anode in contact with an anode electrolyte and configured to
oxidize a metal halide or a metal sulfate from the lower oxidation
state to a higher oxidation state at the anode, a cathode in
contact with a cathode electrolyte, and a reactor operably
connected to the anode chamber and configured to contact the metal
halide or a metal sulfate in the higher oxidation state with
hydrogen gas in an aqueous medium to form an acid, such as,
hydrochloric acid or sulfuric acid wherein the aqueous medium
comprises more than 5 wt % water or more than 5.5 wt % or more than
6 wt % or between 5-90 wt % or between 5-95 wt % or between 5-99 wt
% water or between 5.5-90 wt % or between 5.5-95 wt % or between
5.5-99 wt % water or between 6-90 wt % or between 6-95 wt % or
between 6-99 wt % water.
[0552] In some embodiments of the above described systems, the
cathode is configured to produce hydroxide ions. In some
embodiments of the above described systems, the cathode is
configured to produce hydrogen gas. In some embodiments of the
above described systems, the cathode is configured to produce
water. In some embodiments of the above described systems, the
cathode is ODC. In some embodiments of such methods and systems, no
azeotropic distillation of water is required to reduce the amount
of water in the anode electrolyte. In some embodiments, the system
further includes a separator operably connected to the reactor that
separates the product such as acid or the halogenated hydrocarbon
from the metal ion in the lower oxidation state. In some
embodiments, the system further includes a recirculation system
operably connected to the separator and the anode chamber of the
electrochemical system configured to recirculate at least a portion
of the metal ion in the lower oxidation state from the separator
back to the electrochemical cell. Such recirculation system may be
a conduit, pipe, tube etc. that may be used to transfer the
solutions. Appropriate control valves and computer control systems
may be associated with such recirculation systems.
[0553] In some embodiments, the above described systems are
configured to not produce chlorine gas at the anode. In some
embodiments, the above described systems are configured to not
require oxygen gas and/or chlorine gas for the chlorination of
unsaturated or saturated hydrocarbon to halogenated
hydrocarbon.
[0554] In some embodiments, the electrochemical systems and methods
described herein include the aqueous medium containing more than 5
wt % water. In some embodiments, the aqueous medium includes more
than 5 wt % water; or more than 6 wt %; or more than 8 wt % water;
or more than 10 wt % water; or more than 15 wt % water; or more
than 20 wt % water; or more than 25 wt % water; or more than 50 wt
% water; or more than 60 wt % water; or more than 70 wt % water; or
more than 80 wt % water; or more than 90 wt % water; or about 99 wt
% water; or between 5-100 wt % water; or between 5-99 wt % water;
or between 5-90 wt % water; or between 5-80 wt % water; or between
5-70 wt % water; or between 5-60 wt % water; or between 5-50 wt %
water; or between 5-40 wt % water; or between 5-30 wt % water; or
between 5-20 wt % water; or between 5-10 wt % water; or between
6-100 wt % water; or between 6-99 wt % water; or between 6-90 wt %
water; or between 6-80 wt % water; or between 6-70 wt % water; or
between 6-60 wt % water; or between 6-50 wt % water; or between
6-40 wt % water; or between 6-30 wt % water; or between 6-20 wt %
water; or between 6-10 wt % water; or between 8-100 wt % water; or
between 8-99 wt % water; or between 8-90 wt % water; or between
8-80 wt % water; or between 8-70 wt % water; or between 8-60 wt %
water; or between 8-50 wt % water; or between 8-40 wt % water; or
between 8-30 wt % water; or between 8-20 wt % water; or between
8-10 wt % water; or between 10-100 wt % water; or between 10-75 wt
% water; or between 10-50 wt % water; or between 20-100 wt % water;
or between 20-50 wt % water; or between 50-100 wt % water; or
between 50-75 wt % water; or between 50-60 wt % water; or between
70-100 wt % water; or between 70-90 wt % water; or between 80-100
wt % water. In some embodiments, the aqueous medium may comprise a
water soluble organic solvent.
[0555] In some embodiments of the methods and systems described
herein, the amount of total metal ion in the anode electrolyte or
the amount of copper in the anode electrolyte or the amount of iron
in the anode electrolyte or the amount of chromium in the anode
electrolyte or the amount of tin in the anode electrolyte or the
amount of platinum or the amount of metal ion that is contacted
with the unsaturated or saturated hydrocarbon is between 1-12M; or
between 1-11M; or between 1-10M; or between 1-9M; or between 1-8M;
or between 1-7M; or between 1-6M; or between 1-5M; or between 1-4M;
or between 1-3M; or between 1-2M; or between 2-12M; or between
2-11M; or between 2-10M; or between 2-9M; or between 2-8M; or
between 2-7M; or between 2-6M; or between 2-5M; or between 2-4M; or
between 2-3M; or between 3-12M; or between 3-11M; or between 3-10M;
or between 3-9M; or between 3-8M; or between 3-7M; or between 3-6M;
or between 3-5M; or between 3-4M; or between 4-12M; or between
4-11M; or between 4-10M; or between 4-9M; or between 4-8M; or
between 4-7M; or between 4-6M; or between 4-5M; or between 5-12M;
or between 5-11M; or between 5-10M; or between 5-9M; or between
5-8M; or between 5-7M; or between 5-6M; or between 6-12M; or
between 6-11M; or between 6-10M; or between 6-9M; or between 6-8M;
or between 6-7M; or between 7-12M; or between 7-11M; or between
7-10M; or between 7-9M; or between 7-8M; or between 8-12M; or
between 8-11M; or between 8-10M; or between 8-9M; or between 9-12M;
or between 9-11M; or between 9-10M; or between 10-12M; or between
10-11M; or between 11-12M. In some embodiments, the amount of total
ion in the anode electrolyte, as described above, is the amount of
the metal ion in the lower oxidation state plus the amount of the
metal ion in the higher oxidation state; or the total amount of the
metal ion in the higher oxidation state; or the total amount of the
metal ion in the lower oxidation state.
[0556] In some embodiments of the methods and systems described
herein, the anode electrolyte containing the metal ion may contain
a mixture of the metal ion in the lower oxidation state and the
metal ion in the higher oxidation state. In some embodiments, it
may be desirable to have a mix of the metal ion in the lower
oxidation state and the metal ion in the higher oxidation state in
the anode electrolyte. In some embodiments, the anode electrolyte
that is contacted with the unsaturated or saturated hydrocarbon
contains the metal ion in the lower oxidation state and the metal
ion in the higher oxidation state. In some embodiments, the metal
ion in the lower oxidation state and the metal ion in the higher
oxidation state are present in a ratio such that the reaction of
the metal ion with the unsaturated or saturated hydrocarbon to form
halo or sulfohydrocarbon takes place. In some embodiments, the
ratio of the metal ion in the higher oxidation state to the metal
ion in the lower oxidation state is between 20:1 to 1:20, or
between 14:1 to 1:2; or between 14:1 to 8:1; or between 14:1 to
7:1: or between 2:1 to 1:2; or between 1:1 to 1:2; or between 4:1
to 1:2; or between 7:1 to 1:2.
[0557] In some embodiments of the methods and systems described
herein, the anode electrolyte in the electrochemical systems and
methods of the invention contains the metal ion in the higher
oxidation state in the range of 4-7M, the metal ion in the lower
oxidation state in the range of 0.1-2M and sodium chloride in the
range of 1-3M. The anode electrolyte may optionally contain
0.01-0.1M hydrochloric acid. In some embodiments of the methods and
systems described herein, the anode electrolyte reacted with the
hydrogen gas or the unsaturated or saturated hydrocarbon contains
the metal ion in the higher oxidation state in the range of 4-7M,
the metal ion in the lower oxidation state in the range of 0.1-2M
and sodium chloride in the range of 1-3M. The anode electrolyte may
optionally contain 0.01-0.1M hydrochloric acid.
[0558] In some embodiments of the methods and systems described
herein, the anode electrolyte may contain another cation in
addition to the metal ion. Other cation includes, but is not
limited to, alkaline metal ions and/or alkaline earth metal ions,
such as but not limited to, lithium, sodium, calcium, magnesium,
etc. The amount of the other cation added to the anode electrolyte
may be between 0.01-5M; or between 0.01-1M; or between 0.05-1M; or
between 0.5-2M; or between 1-5M.
[0559] In some embodiments of the methods and systems described
herein, the anode electrolyte may contain an acid. The acid may be
added to the anode electrolyte to bring the pH of the anolyte to 1
or 2 or less. The acid may be hydrochloric acid or sulfuric
acid.
[0560] The systems provided herein include a reactor operably
connected to the anode chamber. The reactor is configured to
contact the metal chloride in the anode electrolyte with the
hydrogen gas or the unsaturated or saturated hydrocarbon. The
reactor may be any means for contacting the metal chloride in the
anode electrolyte with the hydrogen gas or the unsaturated or
saturated hydrocarbon. Such means or such reactor are well known in
the art and include, but not limited to, pipe, duct, tank, series
of tanks, container, tower, conduit, and the like. Some examples of
such reactors are described in FIGS. 7A, 7B, 10A, and 10B herein.
The reactor may be equipped with one or more of controllers to
control temperature sensor, pressure sensor, control mechanisms,
inert gas injector, etc. to monitor, control, and/or facilitate the
reaction. In some embodiments, the reaction between the metal
chloride with metal ion in higher oxidation state and the
unsaturated or saturated hydrocarbon, are carried out in the
reactor at the temperature of between 100-200.degree. C. or between
100-175.degree. C. or between 150-175.degree. C. and pressure of
between 100-500 psig or between 100-400 psig or between 100-300
psig or between 150-350 psig. In some embodiments, the components
of the reactor are lined with Teflon to prevent corrosion of the
components. Some examples of the reactors for carrying out the
reaction of the metal ion in the higher oxidation state with the
hydrogen gas are illustrated in FIGS. 7A and 7B.
[0561] In some embodiments, the unsaturated or saturated
hydrocarbon may be administered to the anode chamber where the
metal halide or metal sulfate with metal in the higher oxidation
state reacts with the unsaturated or saturated hydrocarbon to form
respective products inside the anode chamber. In some embodiments,
the unsaturated or saturated hydrocarbon may be administered to the
anode chamber where the metal chloride with metal in the higher
oxidation state reacts with the unsaturated or saturated
hydrocarbon to form chlorohydrocarbon. Such systems include the
unsaturated or saturated hydrocarbon delivery system which is
operably connected to the anode chamber and is configured to
deliver the unsaturated or saturated hydrocarbon to the anode
chamber. The unsaturated or saturated hydrocarbon may be a solid,
liquid, or a gas. The unsaturated or saturated hydrocarbon may be
supplied to the anode using any means for directing the unsaturated
or saturated hydrocarbon from the external source to the anode
chamber. Such means for directing the unsaturated or saturated
hydrocarbon from the external source to the anode chamber or the
unsaturated or saturated hydrocarbon delivery system are well known
in the art and include, but not limited to, pipe, tanks, duct,
conduit, and the like. In some embodiments, the system or the
unsaturated or saturated hydrocarbon delivery system includes a
duct that directs the unsaturated or saturated hydrocarbon from the
external source to the anode. It is to be understood that the
unsaturated or saturated hydrocarbon may be directed to the anode
from the bottom of the cell, top of the cell or sideways. In some
embodiments, the unsaturated or saturated hydrocarbon gas is
directed to the anode in such a way that the unsaturated or
saturated hydrocarbon gas is not in direct contact with the
anolyte. In some embodiments, the unsaturated or saturated
hydrocarbon may be directed to the anode through multiple entry
ports. The source of unsaturated or saturated hydrocarbon that
provides unsaturated or saturated hydrocarbon to the anode chamber,
in the methods and systems provided herein, includes any source of
unsaturated or saturated hydrocarbon known in the art. Such sources
include, without limitation, commercial grade unsaturated or
saturated hydrocarbon and/or unsaturated or saturated hydrocarbon
generating plants, such as, petrochemical refinery industry.
[0562] In some embodiments, there are provided methods and systems
where the electrochemical cells of the invention are set up on-site
where unsaturated or saturated hydrocarbon is generated, such as
refinery for carrying out the halogenations, such as chlorination
of the unsaturated or saturated hydrocarbon. In some embodiments,
the metal ion containing anolyte from the electrochemical system is
transported to the refinery where the unsaturated or saturated
hydrocarbon is formed for carrying out the halogenations, such as
chlorination of the unsaturated or saturated hydrocarbon. In some
embodiments, the methods and systems of the invention can utilize
the ethylene gas from the refineries without the need for the
filtration or cleaning of the ethylene gas. Typically, the ethylene
gas generating plants scrub the gas to get rid of the impurities.
In some embodiments of the methods and systems of the invention,
such pre-scrubbing of the gas is not needed and can be avoided.
[0563] In some embodiments, the metal generation and the
halogenations, such as chlorination reaction takes place in the
same anode chamber. An illustrative example of such embodiment is
depicted in FIG. 9. It is to be understood that the system 900 of
FIG. 9 is for illustration purposes only and other metal ions with
different oxidations states, other unsaturated or saturated
hydrocarbons, other electrochemical systems forming products other
than alkali, such as water or hydrogen gas in the cathode chamber,
and other unsaturated or saturated hydrocarbon gases, are equally
applicable to the system. In some embodiments, as illustrated in
FIG. 9, the electrochemical system 900 includes an anode situated
near the AEM. The system 900 also includes a gas diffusion layer
(GDL). The anode electrolyte is in contact with the anode on one
side and the GDL on the other side. In some embodiments, the anode
may be situated to minimize the resistance from the anolyte, for
example, the anode may be situated close to AEM or bound to AEM. In
some embodiments, the anode converts metal ions from the lower
oxidation state to the metal ions in the higher oxidation states.
For example, the anode converts metal ions from 1+ oxidation state
to 2+ oxidation state. The Cu.sup.2+ ions combine with chloride
ions to form CuCl.sub.2. The ethylene gas is pressurized into a
gaseous chamber on one side of the GDL. The ethylene gas then
diffuses through the gas diffusion layer and reacts with metal
chloride in the higher oxidation state to form chlorohydrocarbon,
such as ethylene dichloride. The metal chloride CuCl.sub.2 in turn
undergoes reduction to lower oxidation state to form CuCl. In some
embodiments, the anode electrolyte may be withdrawn and the
ethylene dichloride may be separated from the anode electrolyte
using separation techniques well known in the art, including, but
not limited to, filtration, vacuum distillation, fractional
distillation, fractional crystallization, ion exchange resin, etc.
In some embodiments, the ethylene dichloride may be denser than the
anode electrolyte and may form a separate layer inside the anode
chamber. In such embodiments, the ethylene dichloride may be
removed from the bottom of the cell. In some embodiments, the
gaseous chamber on one side of GDL may be vented to remove the gas.
In some embodiments, the anode chamber may be vented to remove the
gaseous ethylene or gaseous byproducts. The system 900 also
includes an oxygen depolarized cathode that produces hydroxide ions
from water and oxygen. The hydroxide ions may be subjected to any
of the carbonate precipitation processes described herein. In some
embodiments, the cathode is not a gas-diffusion cathode but is a
cathode as described in FIG. 4A or 4B. In some embodiments, the
system 900 may be applied to any electrochemical system that
produces alkali.
[0564] In some embodiments of the system and method described
herein, no gas is formed at the cathode. In some embodiments of the
system and method described herein, hydrogen gas is formed at the
cathode. In some embodiments of the system and method described
herein, no gas is formed at the anode. In some embodiments of the
system and method described herein, no gas is used at the anode
other than the gaseous unsaturated or saturated hydrocarbon.
[0565] Another illustrative example of the reactor that is
connected to the electrochemical system is illustrated in FIG. 10A.
As illustrated in FIG. 10A, the anode chamber of the
electrochemical system (electrochemical system can be any
electrochemical system described herein) is connected to a reactor
which is also connected to a source of unsaturated or saturated
hydrocarbon, an example illustrated as ethylene (C.sub.2H.sub.4) in
FIG. 10A. In some embodiments, the electrochemical system and the
reactor are inside the same unit and are connected inside the unit.
The anode electrolyte, containing the metal ion in the higher
oxidation state optionally with the metal ion in the lower
oxidation state, along with ethylene are fed to a prestressed
(e.g., brick-lined) reactor. The chlorination of ethylene takes
place inside the reactor to form ethylene dichloride (EDC or
dichloroethane DCE) and the metal ion in the lower oxidation state.
The reactor may operate in the range of 340-360.degree. F. and
200-300 psig. Other reactor conditions, such as, but not limited
to, metal ion concentration, ratio of metal ion in the lower
oxidation state to the metal ion in the higher oxidation state,
partial pressures of DCE and water vapor can be set to assure high
selectivity operation. Reaction heat may be removed by vaporizing
water. In some embodiments, a cooling surface may not be required
in the reactor and thus no temperature gradients or close
temperature control may be needed. The reactor effluent gases may
be quenched with water (shown as "quench" reactor in FIG. 10A) in
the prestressed (e.g., brick-lined) packed tower. The liquid
leaving the tower maybe cooled further and separated into the
aqueous phase and DCE phase. The aqueous phase may be split part
being recycled to the tower as quench water and the remainder may
be recycled to the reactor or the electrochemical system. The DCE
product may be cooled further and flashed to separate out more
water and dissolved ethylene. This dissolved ethylene may be
recycled as shown in FIG. 10A. The uncondensed gases from the
quench tower may be recycled to the reactor, except for the purge
stream to remove inerts. The purge stream may go through the
ethylene recovery system to keep the overall utilization of
ethylene high, e.g., as high as 95%. Experimental determinations
may be made of flammability limits for ethylene gas at actual
process temperature, pressure and compositions. The construction
material of the plant may include prestressed brick linings,
Hastealloys B and C, inconel, dopant grade titanium (e.g. AKOT,
Grade II), tantalum, Kynar, Teflon, PEEK, glass, or other polymers
or plastics. The reactor may also be designed to continuously flow
the anode electrolyte in and out of the reactor.
[0566] Another illustrative example of the reactor that is
connected to the electrochemical system is as illustrated in FIG.
10B. As illustrated in FIG. 10B, the reactor system 1000 is a glass
vessel A, suspended from the top portion of a metal flange B,
connected to an exit line C, by means of a metal ball socket welded
to the head of the flange. The glass reactor is encased in an
electrically heated metal shell, D. The heat input and the
temperature may be controlled by an automatic temperature
regulator. The hydrocarbon may be introduced into the metal shell
through an opening E and through the glass tube F, which may be
fitted with a fritted glass foot. This arrangement may provide for
pressure equalization on both sides of the glass reactor. The
hydrocarbon may come into contact with the metal solution (metal in
higher oxidation state) at the bottom of the reactor and may bubble
through the medium. The volatile products, water vapor, and/or
unreacted hydrocarbon may leave via line C, equipped optionally
with valve H which may reduce the pressure to atmosphere. The
exiting gases may be passed through an appropriate trapping system
to remove the product. The apparatus may also be fitted with a
bypass arrangement G, which permits the passage of the gas through
the pressure zone without passing through the aqueous metal medium.
In some embodiments, the reduced metal ions in lower oxidation
state that are left in the vessel, are subjected to electrolysis,
as described herein, to regenerate the metal ions in the higher
oxidation state.
[0567] An illustrative embodiment of the invention is as shown in
FIG. 11. As illustrated in FIG. 11, the electrochemical system 600
of FIG. 6 (or alternatively system 400 of FIG. 4A) may be
integrated with CuCl--HCl electrochemical system 1100 (also
illustrated as system in FIG. 4B). In the CuCl--HCl electrochemical
system 1100, the input at the anode is CuCl and HCl which results
in CuCl.sub.2 and hydrogen ions. The hydrogen ions pass through a
proton exchange membrane to the cathode where it forms hydrogen
gas. In some embodiments, chloride conducting membranes may also be
used. In some embodiments, it is contemplated that the CuCl--HCl
cell may run at 0.5V or less and the system 600 may run at 0V or
less. Some deviations from the contemplated voltage may occur due
to resistance losses.
[0568] In one aspect, in the systems and methods provided herein,
the CuCl.sub.2 formed in the anode electrolyte may be used for
copper production. For example, the CuCl.sub.2 formed in the
systems and methods of the invention may be used for leaching
process to extract copper from the copper minerals. For example
only, chalcopyrite is a copper mineral which can be leached in
chloride milieu with the help of an oxidizer, Cu.sup.2+. Divalent
copper may leach the copper of chalcopyrite and other sulfides.
Other minerals such as iron, sulfur, gold, silver etc. can be
recovered once copper is leached out. In some embodiments,
CuCl.sub.2 produced by the electrochemical cells described herein,
may be added to the copper mineral concentrate. The Cu.sup.2+ ions
may oxidize the copper mineral and form CuCl. The CuCl solution
from the concentrate may be fed back to the anode chamber of the
electrochemical cell described herein which may convert CuCl to
CuCl.sub.2. The CuCl.sub.2 may be then fed back to the mineral
concentrate to further oxidize the copper mineral. Once the copper
is leached out, the silver may be cemented out along with further
precipitation of zinc, lead etc. The copper may be then
precipitated out as copper oxide by treatment with alkali which
alkali may be produced by the cathode chamber of the
electrochemical cell. After the precipitation of copper as oxide,
the filtrate NaCl may be returned to the electrochemical cell. The
hydrogen gas generated at the cathode may be used for the reduction
of the copper oxide to form metallic copper (at high temp.). The
molten copper may be cast into copper products like copper wire
rod. This method can be used for low grade ores or for various
types of copper minerals. The electrochemical plant may be fitted
close to the quarry or close to the concentrator eliminating
transportation cost for waste products and allowing transportation
of valuable metal products only.
[0569] The processes and systems described herein may be batch
processes or systems or continuous flow processes or systems.
[0570] The reaction of the hydrogen gas or the unsaturated or
saturated hydrocarbon with the metal ion in the higher oxidation
state, as described in the aspects and embodiments herein, is
carried out in the aqueous medium. In some embodiments, such
reaction may be in a non-aqueous liquid medium which may be a
solvent for the hydrocarbon or hydrogen gas feedstock. The liquid
medium or solvent may be aqueous or non-aqueous. Suitable
non-aqueous solvents being polar and non-polar aprotic solvents,
for example dimethylformamide (DMF), dimethylsulphoxide (DMSO),
halogenated hydrocarbons, for example only, dichloromethane, carbon
tetrachloride, and 1,2-dichloroethane, and organic nitriles, for
example, acetonitrile. Organic solvents may contain a nitrogen atom
capable of forming a chemical bond with the metal in the lower
oxidation state thereby imparting enhanced stability to the metal
ion in the lower oxidation state. In some embodiments, acetonitrile
is the organic solvent.
[0571] In some embodiments, when the organic solvent is used for
the reaction between the metal ion in the higher oxidation state
with the hydrogen gas or hydrocarbon, the water may need to be
removed from the metal containing medium. As such, the metal ion
obtained from the electrochemical systems described herein may
contain water. In some embodiments, the water may be removed from
the metal ion containing medium by azeotropic distillation of the
mixture. In some embodiments, the solvent containing the metal ion
in the higher oxidation state and the hydrogen gas or the
unsaturated or saturated hydrocarbon may contain between 5-90%; or
5-80%; or 5-70%; or 5-60%; or 5-50%; or 5-40%; or 5-30%; or 5-20%;
or 5-10% by weight of water in the reaction medium. The amount of
water which may be tolerated in the reaction medium may depend upon
the particular halide carrier in the medium, the tolerable amount
of water being greater, for example, for copper chloride than for
ferric chloride. Such azeotropic distillation may be avoided when
the aqueous medium is used in the reactions.
[0572] In some embodiments, the reaction of the metal ion in the
higher oxidation state with the hydrogen gas or the unsaturated or
saturated hydrocarbon may take place when the reaction temperature
is above 50.degree. C. up to 350.degree. C. In aqueous media, the
reaction may be carried out under a super atmospheric pressure of
up to 1000 psi or less to maintain the reaction medium in liquid
phase at a temperature of from 50.degree. C. to 200.degree. C.,
typically from about 120.degree. C. to about 180.degree. C.
[0573] In some embodiments, the reaction of the metal ion in the
higher oxidation state with the unsaturated or saturated
hydrocarbon may include a halide carrier. In some embodiments, the
ratio of halide ion: total metal ion in the higher oxidation state
is 1:1; or greater than 1:1; or 1.5:1; or greater than 2:1 and or
at least 3:1. Thus, for example, the ratio in cupric halide
solutions in concentrated hydrochloric acid may be about 2:1 or
3:1. In some embodiments, owing to the high rate of usage of the
halide carrier it may be desired to use the metal halides in high
concentration and to employ saturated or near-saturated solutions
of the metal halides. If desired, the solutions may be buffered to
maintain the pH at the desired level during the halogenation
reaction.
[0574] In some embodiments, a non-halide salt of the metal may be
added to the solution containing metal ion in the higher oxidation
state. The added metal salt may be soluble in the metal halide
solution. Examples of suitable salts for incorporating in cupric
chloride solutions include, but are not limited to, copper
sulphate, copper nitrate and copper tetrafluoroborate. In some
embodiments a metal halide may be added that is different from the
metal halide employed in the methods and systems. For example,
ferric chloride may be added to the cupric chloride systems at the
time of halogenations of the unsaturated hydrocarbon.
[0575] The unsaturated or saturated hydrocarbon feedstock may be
fed to the halogenation vessel continuously or intermittently.
Efficient halogenation may be dependent upon achieving intimate
contact between the feedstock and the metal ion in solution and the
halogenation reaction may be carried out by a technique designed to
improve or maximize such contact. The metal ion solution may be
agitated by stirring or shaking or any desired technique, e.g. the
reaction may be carried out in a column, such as a packed column,
or a trickle-bed reactor or reactors described herein. For example,
where the unsaturated or saturated hydrocarbon is gaseous, a
counter-current technique may be employed wherein the unsaturated
or saturated hydrocarbon is passed upwardly through a column or
reactor and the metal ion solution is passed downwardly through the
column or reactor. In addition to enhancing contact of the
unsaturated or saturated hydrocarbon and the metal ion in the
solution, the techniques described herein may also enhance the rate
of dissolution of the unsaturated or saturated hydrocarbon in the
solution, as may be desirable in the case where the solution is
aqueous and the water-solubility of the unsaturated or saturated
hydrocarbon is low. Dissolution of the feedstock may also be
assisted by higher pressures.
[0576] Mixtures of saturated, unsaturated hydrocarbons and/or
partially halogenated hydrocarbons may be employed. In some
embodiments, partially-halogenated products of the process of the
invention which are capable of further halogenation may be
recirculated to the reaction vessel through a product-recovery
stage and, if appropriate, a metal ion in the lower oxidation state
regeneration stage. In some embodiments, the halogenation reaction
may continue outside the halogenation reaction vessel, for example
in a separate regeneration vessel, and care may need to be
exercised in controlling the reaction to avoid over-halogenation of
the unsaturated or saturated hydrocarbon.
[0577] In some embodiments, the electrochemical systems described
herein are set up close to the plant that produces the unsaturated
or saturated hydrocarbon or that produces hydrogen gas. In some
embodiments, the electrochemical systems described herein are set
up close to the PVC plant. For example, in some embodiments, the
electrochemical system is within the radius of 100 miles near the
ethylene gas, hydrogen gas, vinyl chloride monomer, and/or PVC
plant. In some embodiments, the electrochemical systems described
herein are set up inside or outside the ethylene plant for the
reaction of the ethylene with the metal ion. In some embodiments,
the plants described as above are retrofitted with the
electrochemical systems described herein. In some embodiments, the
anode electrolyte containing the metal ion in the higher oxidation
state is transported to the site of the plants described above. In
some embodiments, the anode electrolyte containing the metal ion in
the higher oxidation state is transported to within 100 miles of
the site of the plants described above. In some embodiments, the
electrochemical systems described herein are set up close to the
plants as described above as well as close to the source of
divalent cations such that the alkali generated in the cathode
electrolyte is reacted with the divalent cations to form
carbonate/bicarbonate products. In some embodiments, the
electrochemical systems described herein are set up close to the
plants as described above, close to the source of divalent cations
and/or the source of carbon dioxide such that the alkali generated
in the cathode electrolyte is able to sequester carbon dioxide to
form carbonate/bicarbonate products. In some embodiments, the
carbon dioxide generated by the refinery that forms the unsaturated
or saturated hydrocarbon is used in the electrochemical systems or
is used in the precipitation of carbonate/bicarbonate products.
Accordingly, in some embodiments, the electrochemical systems
described herein are set up close to the plants as described above,
close to the source of divalent cations and/or the source of carbon
dioxide such as, refineries producing the unsaturated or saturated
hydrocarbon, such that the alkali generated in the cathode
electrolyte is able to sequester carbon dioxide to form
carbonate/bicarbonate products.
[0578] Any number of halo or sulfohydrocarbons may be generated
from the reaction of the metal chloride in the higher oxidation
state with the unsaturated or saturated hydrocarbons, as described
herein. The chlorohydrocarbons may be used in chemical and/or
manufacturing industries. Chlorohydrocarbons may be used as
chemical intermediates or solvents. Solvent uses include a wide
variety of applications, including metal and fabric cleaning,
extraction of fats and oils, and reaction media for chemical
synthesis.
[0579] In some embodiments, the unsaturated hydrocarbon such as
ethylene is reacted with the metal chloride in the higher oxidation
state to form ethylene dichloride. Ethylene dichloride may be used
for variety of purposes including, but not limited to, making
chemicals involved in plastics, rubber and synthetic textile
fibers, such as, but not limited to, vinyl chloride, tri- and
tetra-chloroethylene, vinylidene chloride, trichloroethane,
ethylene glycol, diaminoethylene, polyvinyl chloride, nylon,
viscose rayon, styrene-butadiene rubber, and various plastics; as a
solvent used as degreaser and paint remover; as a solvent for
resins, asphalt, bitumen, rubber, fats, oils, waxes, gums,
photography, photocopying, cosmetics, leather cleaning, and drugs;
fumigant for grains, orchards, mushroom houses, upholstery, and
carpet; as a pickling agent; as a building block reagent as an
intermediate in the production of various organic compounds such
as, ethylenediamine; as a source of chlorine with elimination of
ethene and chloride; as a precursor to 1,1,1-trichloroethane which
is used in dry cleaning; as an anti-knock additive in leaded fuels;
used in extracting spices such as annatto, paprika and turmeric; as
a diluent for pesticide; in paint, coatings, and adhesives; and
combination thereof.
[0580] In the methods and systems described herein, in some
embodiments, no hydrochloric acid is formed in the anode chamber.
In the methods and systems described herein, in some embodiments,
no gas is formed at the anode. In the methods and systems described
herein, in some embodiments, no gas is used at the anode. In the
methods and systems described herein, in some embodiments, hydrogen
gas is formed at the cathode. In the methods and systems described
herein, in some embodiments, no hydrogen gas is formed at the
cathode.
[0581] In some embodiments, a wire is connected between the cathode
and the anode for the current to pass through the cell. In such
embodiments, the cell may act as a battery and the current
generated through the cell may be used to generate alkali which is
withdrawn from the cell. In some embodiments, the resistance of the
cell may go up and the current may go down. In such embodiments, a
voltage may be applied to the electrochemical cell. The resistance
of the cell may increase for various reasons including, but not
limited to, corrosion of the electrodes, solution resistance,
fouling of membrane, etc. In some embodiments, current may be drawn
from the cell using an amperic load.
[0582] In some embodiments, the systems provided herein result in
low to zero voltage systems that generate alkali as compared to
chlor-alkali process or chlor-alkali process with ODC or any other
process that oxidizes metal ions from lower oxidation state to the
higher oxidation state in the anode chamber. In some embodiments,
the systems described herein run at voltage of less than 2V; or
less than 1.2V; or less than 1.1V; or less than 1V; or less than
0.9V; or less than 0.8V; or less than 0.7V; or less than 0.6V; or
less than 0.5V; or less than 0.4V; or less than 0.3V; or less than
0.2V; or less than 0.1V; or at zero volts; or between 0-1.2V; or
between 0-1V; or between 0-0.5 V; or between 0.5-1V; or between
0.5-2V; or between 0-0.1 V; or between 0.1-1V; or between 0.1-2V;
or between 0.01-0.5V; or between 0.01-1.2V; or between 1-1.2V; or
between 0.2-1V; or 0V; or 0.5V; or 0.6V; or 0.7V; or 0.8V; or 0.9V;
or 1V.
[0583] As used herein, the "voltage" includes a voltage or a bias
applied to or drawn from an electrochemical cell that drives a
desired reaction between the anode and the cathode in the
electrochemical cell. In some embodiments, the desired reaction may
be the electron transfer between the anode and the cathode such
that an alkaline solution, water, or hydrogen gas is formed in the
cathode electrolyte and the metal ion is oxidized at the anode. In
some embodiments, the desired reaction may be the electron transfer
between the anode and the cathode such that the metal ion in the
higher oxidation state is formed in the anode electrolyte from the
metal ion in the lower oxidation state. The voltage may be applied
to the electrochemical cell by any means for applying the current
across the anode and the cathode of the electrochemical cell. Such
means are well known in the art and include, without limitation,
devices, such as, electrical power source, fuel cell, device
powered by sun light, device powered by wind, and combination
thereof. The type of electrical power source to provide the current
can be any power source known to one skilled in the art. For
example, in some embodiments, the voltage may be applied by
connecting the anodes and the cathodes of the cell to an external
direct current (DC) power source. The power source can be an
alternating current (AC) rectified into DC. The DC power source may
have an adjustable voltage and current to apply a requisite amount
of the voltage to the electrochemical cell.
[0584] In some embodiments, the current applied to the
electrochemical cell is at least 50 mA/cm.sup.2; or at least 100
mA/cm.sup.2; or at least 150 mA/cm.sup.2; or at least 200
mA/cm.sup.2; or at least 500 mA/cm.sup.2; or at least 1000
mA/cm.sup.2; or at least 1500 mA/cm.sup.2; or at least 2000
mA/cm.sup.2; or at least 2500 mA/cm.sup.2; or between 100-2500
mA/cm.sup.2; or between 100-2000 mA/cm.sup.2; or between 100-1500
mA/cm.sup.2; or between 100-1000 mA/cm.sup.2; or between 100-500
mA/cm.sup.2; or between 200-2500 mA/cm.sup.2; or between 200-2000
mA/cm.sup.2; or between 200-1500 mA/cm.sup.2; or between 200-1000
mA/cm.sup.2; or between 200-500 mA/cm.sup.2; or between 500-2500
mA/cm.sup.2; or between 500-2000 mA/cm.sup.2; or between 500-1500
mA/cm.sup.2; or between 500-1000 mA/cm.sup.2; or between 1000-2500
mA/cm.sup.2; or between 1000-2000 mA/cm.sup.2; or between 1000-1500
mA/cm.sup.2; or between 1500-2500 mA/cm.sup.2; or between 1500-2000
mA/cm.sup.2; or between 2000-2500 mA/cm.sup.2.
[0585] In some embodiments, the cell runs at voltage of between
0-3V when the applied current is 100-250 mA/cm.sup.2 or 100-150
mA/cm.sup.2 or 100-200 mA/cm.sup.2 or 100-300 mA/cm.sup.2 or
100-400 mA/cm.sup.2 or 100-500 mA/cm.sup.2 or 150-200 mA/cm.sup.2
or 200-150 mA/cm.sup.2 or 200-300 mA/cm.sup.2 or 200-400
mA/cm.sup.2 or 200-500 mA/cm.sup.2 or 150 mA/cm.sup.2 or 200
mA/cm.sup.2 or 300 mA/cm.sup.2 or 400 mA/cm.sup.2 or 500
mA/cm.sup.2 or 600 mA/cm.sup.2. In some embodiments, the cell runs
at between 0-1V. In some embodiments, the cell runs at between
0-1.5V when the applied current is 100-250 mA/cm.sup.2 or 100-150
mA/cm.sup.2 or 150-200 mA/cm.sup.2 or 150 mA/cm.sup.2 or 200
mA/cm.sup.2. In some embodiments, the cell runs at between 0-1V at
an amperic load of 100-250 mA/cm.sup.2 or 100-150 mA/cm.sup.2 or
150-200 mA/cm.sup.2 or 150 mA/cm.sup.2 or 200 mA/cm.sup.2. In some
embodiments, the cell runs at 0.5V at a current or an amperic load
of 100-250 mA/cm.sup.2 or 100-150 mA/cm.sup.2 or 150-200
mA/cm.sup.2 or 150 mA/cm.sup.2 or 200 mA/cm.sup.2.
[0586] In some embodiments, the systems and methods provided herein
further include a percolator and/or a spacer between the anode and
the ion exchange membrane and/or the cathode and the ion exchange
membrane. The electrochemical systems containing percolator and/or
spacers are described in U.S. Provisional Application No.
61/442,573, filed Feb. 14, 2011, which is incorporated herein by
reference in its entirety in the present disclosure.
[0587] The systems provided herein are applicable to or can be used
for any of one or more methods described herein. In some
embodiments, the systems provided herein further include an oxygen
gas supply or delivery system operably connected to the cathode
chamber. The oxygen gas delivery system is configured to provide
oxygen gas to the gas-diffusion cathode. In some embodiments, the
oxygen gas delivery system is configured to deliver gas to the
gas-diffusion cathode where reduction of the gas is catalyzed to
hydroxide ions. In some embodiments, the oxygen gas and water are
reduced to hydroxide ions; un-reacted oxygen gas in the system is
recovered; and re-circulated to the cathode. The oxygen gas may be
supplied to the cathode using any means for directing the oxygen
gas from the external source to the cathode. Such means for
directing the oxygen gas from the external source to the cathode or
the oxygen gas delivery system are well known in the art and
include, but not limited to, pipe, duct, conduit, and the like. In
some embodiments, the system or the oxygen gas delivery system
includes a duct that directs the oxygen gas from the external
source to the cathode. It is to be understood that the oxygen gas
may be directed to the cathode from the bottom of the cell, top of
the cell or sideways. In some embodiments, the oxygen gas is
directed to the back side of the cathode where the oxygen gas is
not in direct contact with the catholyte. In some embodiments, the
oxygen gas may be directed to the cathode through multiple entry
ports. The source of oxygen that provides oxygen gas to the
gas-diffusion cathode, in the methods and systems provided herein,
includes any source of oxygen known in the art. Such sources
include, without limitation, ambient air, commercial grade oxygen
gas from cylinders, oxygen gas obtained by fractional distillation
of liquefied air, oxygen gas obtained by passing air through a bed
of zeolites, oxygen gas obtained from electrolysis of water, oxygen
obtained by forcing air through ceramic membranes based on
zirconium dioxides by either high pressure or electric current,
chemical oxygen generators, oxygen gas as a liquid in insulated
tankers, or combination thereof. In some embodiments, the source of
oxygen may also provide carbon dioxide gas. In some embodiments,
the oxygen from the source of oxygen gas may be purified before
being administered to the cathode chamber. In some embodiments, the
oxygen from the source of oxygen gas is used as is in the cathode
chamber.
Alkali in the Cathode Chamber
[0588] The cathode electrolyte containing the alkali maybe
withdrawn from the cathode chamber. The alkali may be separated
from the cathode electrolyte using techniques known in the art,
including but not limited to, diffusion dialysis. In some
embodiments, the alkali produced in the methods and systems
provided herein, is used as is commercially or is used in
commercial processes known in the art. The purity of the alkali
formed in the methods and systems may vary depending on the end use
requirements. For example, methods and systems provided herein that
use an electrochemical cell equipped with membranes, may form a
membrane quality alkali which may be substantially free of
impurities. In some embodiments, a less pure alkali may also be
formed by avoiding the use of membranes or by adding the carbon to
the cathode electrolyte. In some embodiments, the alkali formed in
the cathode electrolyte is more than 2% w/w or more than 5% w/w or
between 5-50% w/w.
[0589] In some embodiments, the alkali produced in the cathode
chamber may be used in various commercial processes, as described
herein. In some embodiments, the system appropriate to such uses
may be operatively connected to the electrochemical unit, or the
alkali may be transported to the appropriate site for use. In some
embodiments, the systems include a collector configured to collect
the alkali from the cathode chamber and connect it to the
appropriate process which may be any means to collect and process
the alkali including, but not limited to, tanks, collectors, pipes
etc. that can collect, process, and/or transfer the alkali produced
in the cathode chamber for use in the various commercial
processes.
[0590] In some embodiments, the alkali, such as, sodium hydroxide
produced in the cathode electrolyte is used as is for commercial
purposes or is treated in variety of ways well known in the art.
For example, sodium hydroxide formed in the catholyte may be used
as a base in the chemical industry, in household, and/or in the
manufacture of pulp, paper, textiles, drinking water, soaps,
detergents and drain cleaner. In some embodiments, the sodium
hydroxide may be used in making paper. Along with sodium sulfide,
sodium hydroxide may be a component of the white liquor solution
used to separate lignin from cellulose fibers in the Kraft process.
It may also be useful in several later stages of the process of
bleaching the brown pulp resulting from the pulping process. These
stages may include oxygen delignification, oxidative extraction,
and simple extraction, all of which may require a strong alkaline
environment with a pH>10.5 at the end of the stages. In some
embodiments, the sodium hydroxide may be used to digest tissues.
This process may involve placing of a carcass into a sealed chamber
and then putting the carcass in a mixture of sodium hydroxide and
water, which may break chemical bonds keeping the body intact. In
some embodiments, the sodium hydroxide may be used in Bayer process
where the sodium hydroxide is used in the refining of alumina
containing ores (bauxite) to produce alumina (aluminium oxide). The
alumina is the raw material that may be used to produce aluminium
metal via the electrolytic Hall-Heroult process. The alumina may
dissolve in the sodium hydroxide, leaving impurities less soluble
at high pH such as iron oxides behind in the form of a highly
alkaline red mud. In some embodiments, the sodium hydroxide may be
used in soap making process. In some embodiments, the sodium
hydroxide may be used in the manufacture of biodiesel where the
sodium hydroxide may be used as a catalyst for the
trans-esterification of methanol and triglycerides. In some
embodiments, the sodium hydroxide may be used as a cleansing agent,
such as, but not limited to, degreaser on stainless and glass
bakeware.
[0591] In some embodiments, the sodium hydroxide may be used in
food preparation. Food uses of sodium hydroxide include, but not
limited to, washing or chemical peeling of fruits and vegetables,
chocolate and cocoa processing, caramel coloring production,
poultry scalding, soft drink processing, and thickening ice cream.
Olives may be soaked in sodium hydroxide to soften them, while
pretzels and German lye rolls may be glazed with a sodium hydroxide
solution before baking to make them crisp. In some embodiments, the
sodium hydroxide may be used in homes as a drain cleaning agent for
clearing clogged drains. In some embodiments, the sodium hydroxide
may be used as a relaxer to straighten hair. In some embodiments,
the sodium hydroxide may be used in oil refineries and for oil
drilling, as it may increase the viscosity and prevent heavy
materials from settling. In the chemical industry, the sodium
hydroxide may provide fuctions of neutralisation of acids,
hydrolysis, condensation, saponification, and replacement of other
groups in organic compounds of hydroxyl ions. In some embodiments,
the sodium hydroxide may be used in textile industry. Mercerizing
of fiber with sodium hydroxide solution may enable greater
tensional strength and consistent lustre. It may also remove waxes
and oils from fiber to make the fiber more receptive to bleaching
and dying. Sodium hydroxide may also be used in the production of
viscose rayon. In some embodiments, the sodium hydroxide may be
used to make sodium hypochlorite which may be used as a household
bleach and disinfectant and to make sodium phenolate which may be
used in antiseptics and for the manufacture of Aspirin.
Contact of Carbon Dioxide with Cathode Electrolyte
[0592] In one aspect, there are provided methods and systems as
described herein, that include contacting carbon dioxide with the
cathode electrolyte either inside the cathode chamber or outside
the cathode chamber. In one aspect, there are provided methods
including contacting an anode with a metal ion in an anode
electrolyte in an anode chamber; converting or oxidizing the metal
ion from a lower oxidation state to a higher oxidation state in the
anode chamber; contacting a cathode with a cathode electrolyte in a
cathode chamber; forming an alkali in the cathode electrolyte; and
contacting the alkali in the cathode electrolyte with carbon from a
source of carbon, such as carbon dioxide from a source of carbon
dioxide. In some embodiments, the methods further comprises using
the metal in the higher oxidation state formed in the anode chamber
as is (as described herein) or use it for reaction with hydrogen
gas or reaction with unsaturated or saturated hydrocarbons (as
described herein). In some embodiments, there is provided a method
comprising contacting an anode with an anode electrolyte; oxidizing
metal ion from a lower oxidation state to a higher oxidation state
at the anode; contacting a cathode with a cathode electrolyte;
producing hydroxide ions in the cathode electrolyte; and contacting
the cathode electrolyte with an industrial waste gas comprising
carbon dioxide or with a solution of carbon dioxide comprising
bicarbonate ions.
[0593] In another aspect, there are provided systems including an
anode chamber containing an anode in contact with a metal ion in an
anode electrolyte, wherein the anode is configured to convert the
metal ion from a lower oxidation state to a higher oxidation state;
a cathode chamber containing a cathode in contact with a cathode
electrolyte wherein the cathode is configured to produce an alkali;
and a contactor operably connected to the cathode chamber and
configured to contact carbon from a source of carbon such as carbon
dioxide from a source of carbon dioxide with the alkali in the
cathode electrolyte. In some embodiments, the system further
includes a reactor operably connected to the anode chamber and
configured to react the metal ion in the higher oxidation state
with hydrogen gas or with unsaturated or saturated hydrocarbons (as
described herein).
[0594] In some embodiments, the carbon from the source of carbon is
treated with the cathode electrolyte to form a solution of
dissolved carbon dioxide in the alkali of the cathode electrolyte.
The alkali present in the cathode electrolyte may facilitate
dissolution of carbon dioxide in the solution. The solution with
dissolved carbon dioxide includes carbonic acid, bicarbonate,
carbonate, or any combination thereof. In such method and system,
the carbon from the source of carbon includes gaseous carbon
dioxide from an industrial process or a solution of carbon dioxide
from a gas/liquid contactor which is in contact with the gaseous
carbon dioxide from the industrial process. Such contactor is
further defined herein. In some embodiments of the systems
including the contactor, the cathode chamber includes bicarbonate
and carbonate ions in addition to hydroxide ions.
[0595] An illustrative example of an electrochemical system
integrated with carbon from a source of carbon is as illustrated in
FIG. 12. It is to be understood that the system 1200 of FIG. 12 is
for illustration purposes only and other metal ions with different
oxidations states (e.g., chromium, tin etc.); other electrochemical
systems described herein such as electrochemical systems of FIGS.
1A, 1B, 2, 3A, 3B, 4A, 5A, 5C, 6, 8A, 8B, 9, and 11; and the third
electrolyte other than sodium chloride such as sodium sulfate, are
variations that are equally applicable to this system. The
electrochemical system 1200 of FIG. 12 includes an anode and a
cathode separated by anion exchange membrane and cation exchange
membrane creating a third chamber containing a third electrolyte,
NaCl. The metal ion is oxidized in the anode chamber from the lower
oxidation state to the higher oxidation state which metal in the
higher oxidation state is then used for reactions in a reactor,
such as reaction with hydrogen gas or reaction with unsaturated or
saturated hydrocarbon. The products formed by such reactions are
described herein. The cathode is illustrated as hydrogen gas
forming cathode in FIG. 12 although an ODC is equally applicable to
this system. The cathode chamber is connected with a gas/liquid
contactor that is in contact with gaseous carbon dioxide. The
cathode electrolyte containing alkali such as hydroxide and/or
sodium carbonate is circulated to the gas/liquid contactor which
brings the cathode electrolyte in contact with the gaseous carbon
dioxide resulting in the formation of sodium bicarbonate/sodium
carbonate solution. This solution of dissolved carbon dioxide is
then circulated to the cathode chamber where the alkali formed at
the cathode converts the bicarbonate ions to the carbonate ions
bringing the pH of the cathode electrolyte to less than 12. This in
turn brings the voltage of the cell down to less than 2 V. The
sodium carbonate solution thus formed may be re-circulated back to
the gas/liquid contactor for further contact with gaseous carbon
dioxide or may be taken out for carrying out the calcium carbonate
precipitation process as described herein. In some embodiments, the
gaseous carbon dioxide is administered directly into the cathode
chamber without the intermediate use of the gas/liquid contactor.
In some embodiments, the bicarbonate solution from the gas/liquid
contactor is not administered to the cathode chamber but is instead
used for the precipitation of the bicarbonate product.
[0596] The methods and systems related to the contact of the carbon
from the source of carbon with the cathode electrolyte (when
cathode is either ODC or hydrogen gas producing cathode), as
described herein and illustrated in FIG. 12, may result in voltage
savings as compared to methods and systems that do not contact the
carbon from the source of carbon with the cathode electrolyte. The
voltage savings in-turn may result in less electricity consumption
and less carbon dioxide emission for electricity generation. This
may result in the generation of greener chemicals such as sodium
carbonate, sodium bicarbonate, calcium/magnesium bicarbonate or
carbonate, halogentated hydrocarbons and/or acids, that are formed
by the efficient and energy saving methods and systems of the
invention. In some embodiments, the electrochemical cell, where
carbon from the source of carbon (such as carbon dioxide gas or
sodium carbonate/bicarbonate solution from the gas/liquid
contactor) is contacted with the alkali generated by the cathode,
has a theoretical cathode half cell voltage saving or theoretical
total cell voltage savings of more than 0.1V, or more than 0.2V, or
more than 0.5V, or more than 1V, or more than 1.5V, or between
0.1-1.5V, or between 0.1-1V, or between 0.2-1.5V, or between
0.2-1V, or between 0.5-1.5V, or between 0.5-1V as compared to the
electrochemical cell where no carbon is contacted with the alkali
from the cathode such as, ODC or the hydrogen gas producing
cathode. In some embodiments, this voltage saving is achieved with
a cathode electrolyte pH of between 7-13, or between 6-12, or
between 7-12, or between 7-10, or between 6-13.
[0597] Based on the Nernst equation explained earlier, when metal
in the lower oxidation state is oxidized to metal in the higher
oxidation state at the anode as follows:
Cu.sup.+.fwdarw.Cu.sup.2++2e.sup.-
E.sub.anode based on concentration of copper II species is between
0.159-0.75V.
[0598] When water is reduced to hydroxide ions and hydrogen gas at
the cathode (as illustrated in FIG. 4A or FIG. 12) and the
hydroxide ions come into contact with the bicarbonate ions (such as
carbon dioxide gas dissolved directly into the cathode electrolyte
or sodium carbonate/bicarbonate solution from the gas/liquid
contactor circulated into the cathode electrolyte) to form
carbonate, the pH of the cathode electrolyte goes down from 14 to
less than 14, as follows: [0599] E.sub.cathode=-0.059 pH.sub.c,
where pH.sub.c is the pH of the cathode electrolyte=10 [0600]
E.sub.cathode=-0.59
[0601] The E.sub.total then is between 0.749 to 1.29, depending on
the concentration of copper ions in the anode electrolyte. The
E.sub.cathode=-0.59 is a saving of more than 200 mV or between 200
mV to 500 mV or between 100-500 mV over the E.sub.cathode=-0.83 for
the hydrogen gas producing cathode that is not in contact with
bicarbonate/carbonate ions. The E.sub.Total=0.749 to 1.29 is a
saving of more than 200 mV or between 200 mV-1.2V or between 100
mV-1.5V over the E.sub.Total=0.989 to 1.53 for the hydrogen gas
producing cathode that is not in contact with bicarbonate/carbonate
ions.
[0602] Similarly, when water is reduced to hydroxide ions at ODC
(as illustrated in FIG. 5A) and the hydroxide ions come into
contact with the bicarbonate ions (such as carbon dioxide gas
dissolved directly into the cathode electrolyte or sodium
carbonate/bicarbonate solution from the gas/liquid contactor
circulated into the cathode electrolyte) to form carbonate, the pH
of the cathode electrolyte goes down from 14 to less than 14, as
follows: [0603] E.sub.cathode=1.224-0.059 pH.sub.c, where
pH.sub.c=10 [0604] E.sub.cathode=0.636V
[0605] E.sub.total then is between -0.477 to 0.064V depending on
the concentration of copper ions in the anode electrolyte. The
E.sub.cathode=0.636 is a saving of more than 100 mV or between 100
mV to 200 mV or between 100-500 mV or between 200-500 mV over the
E.sub.cathode=0.4 for the ODC that is not in contact with
bicarbonate/carbonate ions. The E.sub.Total=-0.477 to 0.064V is a
saving of more than 200 mV or between 200 mV-1.2V or between 100
mV-1.5V over the E.sub.Total=-0.241 to 0.3 for the ODC that is not
in contact with bicarbonate/carbonate ions.
[0606] As described above, as the cathode electrolyte is allowed to
increase to a pH of 14 or greater, the difference between the anode
half-cell potential and the cathode half cell potential would
increase. With increased duration of cell operation without
CO.sub.2 addition or other intervention, e.g., diluting with water,
the required cell potential would continue to increase. The
operation of the electrochemical cell with the cathode pH between
7-13 or between 7-12 provides a significant energy savings.
[0607] Thus, for different pH values in the cathode electrolyte,
hydroxide ions, carbonate ions and/or bicarbonate ions are produced
in the cathode electrolyte when the voltage applied across the
anode and cathode is less than 2.9, or less than 2.5, or less than
2.1, or 2.0, or less than 1.5, or less than 1.0, or less than 0.5,
or between 0.5-1.5V, while the pH in the cathode electrolyte is
between 7-13 or 7-12 or 6-12 or 7-10.
[0608] In some embodiments, the source of carbon is any gaseous
source of carbon dioxide and/or any source that provides dissolved
form or solution of carbon dioxide. The dissolved form of carbon
dioxide or solution of carbon dioxide includes carbonic acid,
bicarbonate ions, carbonate ions, or combination thereof. In some
embodiments, the oxygen gas and/or carbon dioxide gas supplied to
the cathode is from any oxygen source and carbon dioxide gas source
known in the art. The source of oxygen gas and the source of carbon
dioxide gas may be same or may be different. Some examples of the
oxygen gas source and carbon dioxide gas source are as described
herein.
[0609] In some embodiments, the alkali produced in the cathode
chamber may be treated with a gaseous stream of carbon dioxide
and/or a dissolved form of carbon dioxide to form
carbonate/bicarbonate products which may be used as is for
commercial purposes or may be treated with divalent cations, such
as, but not limited to, alkaline earth metal ions to form alkaline
earth metal carbonates and/or bicarbonates.
[0610] As used herein, "carbon from source of carbon" includes
gaseous form of carbon dioxide or dissolved form or solution of
carbon dioxide. The carbon from source of carbon includes CO.sub.2,
carbonic acid, bicarbonate ions, carbonate ions, or a combination
thereof. As used herein, "source of carbon" includes any source
that provides gaseous and/or dissolved form of carbon dioxide. The
sources of carbon include, but not limited to, waste streams or
industrial processes that provide a gaseous stream of CO.sub.2; a
gas/liquid contactor that provides a solution containing CO.sub.2,
carbonic acid, bicarbonate ions, carbonate ions, or combination
thereof; and/or bicarbonate brine solution.
[0611] The gaseous CO.sub.2 is, in some embodiments, a waste stream
or product from an industrial plant. The nature of the industrial
plant may vary in these embodiments. The industrial plants include,
but not limited to, refineries that form unsaturated or saturated
hydrocarbons, power plants (e.g., as described in detail in
International Application No. PCT/US08/88318, titled, "Methods of
sequestering CO.sub.2," filed 24 Dec. 2008, the disclosure of which
is herein incorporated by reference in its entirety), chemical
processing plants, steel mills, paper mills, cement plants (e.g.,
as described in further detail in U.S. Provisional Application Ser.
No. 61/088,340, the disclosure of which is herein incorporated by
reference in its entirety), and other industrial plants that
produce CO.sub.2 as a byproduct. By waste stream is meant a stream
of gas (or analogous stream) that is produced as a byproduct of an
active process of the industrial plant. The gaseous stream may be
substantially pure CO.sub.2 or a multi-component gaseous stream
that includes CO.sub.2 and one or more additional gases.
Multi-component gaseous streams (containing CO.sub.2) that may be
employed as a CO.sub.2 source in embodiments of the methods include
both reducing, e.g., syngas, shifted syngas, natural gas, and
hydrogen and the like, and oxidizing condition streams, e.g., flue
gases from combustion, such as combustion of methane. Exhaust gases
containing NOx, SOx, VOCs, particulates and Hg would incorporate
these compounds along with the carbonate in the precipitated
product. Particular multi-component gaseous streams of interest
that may be treated according to the subject invention include, but
not limited to, oxygen containing combustion power plant flue gas,
turbo charged boiler product gas, coal gasification product gas,
shifted coal gasification product gas, anaerobic digester product
gas, wellhead natural gas stream, reformed natural gas or methane
hydrates, and the like. In instances where the gas contains both
carbon dioxide and oxygen gas, the gas may be used both as a source
of carbon dioxide as well as a source of oxygen. For example, flue
gases obtained from the combustion of oxygen and methane may
contain oxygen gas and may provide a source of both carbon dioxide
gas as well as oxygen gas.
[0612] Thus, the waste streams may be produced from a variety of
different types of industrial plants. Suitable waste streams for
the invention include waste streams, such as, flue gas, produced by
industrial plants that combust fossil fuels (e.g., coal, oil,
natural gas) or anthropogenic fuel products of naturally occurring
organic fuel deposits (e.g., tar sands, heavy oil, oil shale,
etc.). In some embodiments, a waste stream suitable for systems and
methods of the invention is sourced from a coal-fired power plant,
such as a pulverized coal power plant, a supercritical coal power
plant, a mass burn coal power plant, a fluidized bed coal power
plant. In some embodiments, the waste stream is sourced from gas or
oil-fired boiler and steam turbine power plants, gas or oil-fired
boiler simple cycle gas turbine power plants, or gas or oil-fired
boiler combined cycle gas turbine power plants. In some
embodiments, waste streams produced by power plants that combust
syngas (i.e., gas that is produced by the gasification of organic
matter, for example, coal, biomass, etc.) are used. In some
embodiments, waste streams from integrated gasification combined
cycle (IGCC) plants are used. In some embodiments, waste streams
produced by Heat Recovery Steam Generator (HRSG) plants are used to
produce compositions in accordance with systems and methods
provided herein.
[0613] Waste streams produced by cement plants are also suitable
for systems and methods provided herein. Cement plant waste streams
include waste streams from both wet process and dry process plants,
which plants may employ shaft kilns or rotary kilns, and may
include pre-calciners. These industrial plants may each burn a
single fuel, or may burn two or more fuels sequentially or
simultaneously.
[0614] Although carbon dioxide may be present in ordinary ambient
air, in view of its very low concentration, ambient carbon dioxide
may not provide sufficient carbon dioxide to achieve the formation
of the bicarbonate and/or carbonate as is obtained when carbon from
the source of carbon is contacted with the cathode electrolyte. In
some embodiments of the system and method, the pressure inside the
electrochemical system may be greater than the ambient atmospheric
pressure in the ambient air and hence ambient carbon dioxide may
typically be prevented from infiltrating into the cathode
electrolyte.
[0615] The contact system or the contactor includes any means for
contacting the carbon from the source of carbon to the cathode
electrolyte inside a cathode chamber or outside the cathode
chamber. Such means for contacting the carbon to the cathode
electrolyte or the contactor configured to contact carbon from a
source of carbon with the cathode chamber, are well known in the
art and include, but not limited to, injection, pipe, duct,
conduit, and the like. In some embodiments, the system includes a
duct that directs the carbon to the cathode electrolyte inside a
cathode chamber. It is to be understood that when the carbon from
the source of carbon is contacted with the cathode electrolyte
inside the cathode chamber, the carbon may be injected to the
cathode electrolyte from the bottom of the cell, top of the cell,
from the side inlet in the cell, and/or from all entry ports
depending on the amount of carbon desired in the cathode chamber.
The amount of carbon from the source of carbon inside the cathode
chamber may be dependent on the flow rate of the solution, desired
pH of the cathode electrolyte, and/or size of the cell. Such
optimization of the amount of the carbon from the source of carbon
is well within the scope of the invention. In some embodiments, the
carbon from the source of carbon is selected from gaseous carbon
dioxide from an industrial process or a solution of carbon dioxide
from a gas/liquid contactor in contact with the gaseous carbon
dioxide from the industrial process.
[0616] In some embodiments, the cathode chamber includes a
partition that helps facilitate delivery of the carbon dioxide gas
and/or solution of carbon dioxide in the cathode chamber. In some
embodiments, the partition may help prevent mixing of the carbon
dioxide gas with the oxygen gas and/or mixing of the carbon dioxide
gas in the cathode chamber with the hydrogen gas in the anode
chamber. In some embodiments, the partition results in the
catholyte with a gaseous form of carbon dioxide as well as
dissolved form of carbon dioxide. In some embodiments, the systems
provided herein include a partition that partitions the cathode
electrolyte into a first cathode electrolyte portion and a second
cathode electrolyte portion, where the second cathode electrolyte
portion that includes dissolved carbon dioxide contacts the
cathode; and where the first cathode electrolyte portion that
includes dissolved carbon dioxide and gaseous carbon dioxide,
contacts the second cathode electrolyte portion under the
partition. In the system, the partition is positioned in the
cathode electrolyte such that a gas, e.g., carbon dioxide in the
first cathode electrolyte portion is isolated from cathode
electrolyte in the second cathode electrolyte portion. Thus, the
partition may serve as a means to prevent mixing of the gases on
the cathode and/or the gases and or vapor from the anode. Such
partition is described in U.S. Publication No. 2010/0084280, filed
Nov. 12, 2009, which is incorporated herein by reference in its
entirety in the present disclosure.
[0617] In some embodiments, the source of carbon is a gas/liquid
contactor that provides a dissolved form or solution of carbon
dioxide containing CO.sub.2, carbonic acid, bicarbonate ions,
carbonate ions, or combination thereof. In some embodiments, the
solution charged with the partially or fully dissolved CO.sub.2 is
made by sparging or diffusing the CO.sub.2 gaseous stream through
slurry or solution to make a CO.sub.2 charged water. In some
embodiments, the slurry or solution charged with CO.sub.2 includes
a proton removing agent obtained from the cathode electrolyte of an
electrochemical cell, as described herein. In some embodiments, the
gas/liquid contactor may include a bubble chamber where the
CO.sub.2 gas is bubbled through the slurry or the solution
containing the proton removing agent. In some embodiments, the
contactor may include a spray tower where the slurry or the
solution containing the proton removing agent is sprayed or
circulated through the CO.sub.2 gas. In some embodiments, the
contactor may include a pack bed to increase the surface area of
contact between the CO.sub.2 gas and the solution containing the
proton removing agent. For example, the gas/liquid contactor or the
absorber may contain a slurry or solution or pack bed of sodium
carbonate. The CO.sub.2 is sparged through this slurry or the
solution or the pack bed where the alkaline medium facilitates
dissolution of CO.sub.2 in the solution. After the dissolution of
CO.sub.2, the solution may contain bicarbonate, carbonate, or
combination thereof. In some embodiments, a typical absorber or the
contactor fluid temperature is 32-37.degree. C. The absorber or
contactor for absorbing CO.sub.2 in the solution is described in
U.S. application Ser. No. 12/721,549, filed on Mar. 10, 2010, which
is incorporated herein by reference in its entirety in the present
disclosure. The solution containing the carbonate/bicarbonate
species may be withdrawn from the gas/liquid contactor to form
bicarbonate/carbonate products. In some embodiments, the
carbonate/bicarbonate solution may be transferred to the cathode
electrolyte containing the alkali. The alkali may substantially or
fully convert the bicarbonate to carbonate to form carbonate
solution. The carbonate solution may be re-circulated back to the
gas/liquid contactor or may be withdrawn from the cathode chamber
and treated with divalent cations to form bicarbonate/carbonate
products.
[0618] In some embodiments, the alkali produced in the cathode
electrolyte may be delivered to the gas/liquid contactor where the
carbon dioxide gas comes into contact with the alkali. The carbon
dioxide gas after coming into contact with the alkali may result in
the formation of carbonic acid, bicarbonate ions, carbonate ions,
or combination thereof. The dissolved form of carbon dioxide may be
then delivered back to the cathode chamber where the alkali may
convert the bicarbonate into the carbonate. The
carbonate/bicarbonate mix may be then used as is for commercial
purposes or is treated with divalent cations, such as, alkaline
earth metal ions to form alkaline earth metal
carbonates/bicarbonates.
[0619] The system in some embodiments includes a cathode
electrolyte circulating system adapted for withdrawing and
circulating cathode electrolyte in the system. In some embodiments,
the cathode electrolyte circulating system includes a gas/liquid
contactor outside the cathode chamber that is adapted for
contacting the carbon from the source of carbon with the
circulating cathode electrolyte, and for re-circulating the
electrolyte in the system. As the pH of the cathode electrolyte may
be adjusted by withdrawing and/or circulating cathode
electrolyte/carbon from the source of carbon from the system, the
pH of the cathode electrolyte compartment can be regulated by
regulating an amount of cathode electrolyte removed from the
system, passed through the gas/liquid contactor, and/or
re-circulated back into the cathode chamber.
[0620] In some embodiments, the source of carbon is the bicarbonate
brine solution. The bicarbonate brine solution, is as described in
U.S. Provisional Application No. 61/433,641, filed on Jan. 18, 2011
and U.S. Provisional Application No. 61/408,325, filed Oct. 29,
2010, which are both incorporated herein by reference in their
entirety in the present disclosure. As used herein, the
"bicarbonate brine solution" includes any brine containing
bicarbonate ions. In some embodiments, the brine is a synthetic
brine such as a solution of brine containing the bicarbonate, e.g.,
sodium bicarbonate, potassium bicarbonate, lithium bicarbonate etc.
In some embodiments, the brine is a naturally occurring bicarbonate
brine, e.g., subterranean brine such as naturally occurring lakes.
In some embodiments, the bicarbonate brine is made from
subterranean brines, such as but not limited to, carbonate brines,
alkaline brines, hard brines, and/or alkaline hard brines. In some
embodiments, the bicarbonate brine is made from minerals where the
minerals are crushed and dissolved in brine and optionally further
processed. The minerals can be found under the surface, on the
surface, or subsurface of the lakes. The bicarbonate brine can also
be made from evaporite. The bicarbonate brine may include other
oxyanions of carbon in addition to bicarbonate (HCO.sub.3.sup.-),
such as, but not limited to, carbonic acid (H.sub.2CO.sub.3) and/or
carbonate (CO.sub.3.sup.2-).
[0621] In some embodiments of the electrochemical cells described
herein, the system is configured to produce carbonate ions by a
reaction of the carbon such as, CO.sub.2, carbonic acid,
bicarbonate ions, carbonate ions, or combination thereof, from the
source of carbon with an alkali, such as, sodium hydroxide from the
cathode electrolyte. In some embodiments (not shown in figures),
the carbon from the source of carbon, such as gaseous form of
carbon dioxide may be contacted with the catholyte inside the
cathode chamber and the catholyte containing
hydroxide/carbonate/bicarbonate may be withdrawn from the cathode
chamber and contacted with the gas/liquid contactor outside the
cathode chamber. In such embodiments, the catholyte from the
gas/liquid contactor may be contacted back again with the catholyte
inside the cathode chamber.
[0622] For the systems where the carbon from the source of carbon
is contacted with the cathode electrolyte outside the cathode
chamber, the alkali containing cathode electrolyte may be withdrawn
from the cathode chamber and may be added to a container configured
to contain the carbon from the source of carbon. The container may
have an input for the source of carbon such as a pipe or conduit,
etc. or a pipeline in communication with the gaseous stream of
CO.sub.2, a solution containing dissolved form of CO.sub.2, and/or
the bicarbonate brine. The container may also be in fluid
communication with a reactor where the source of carbon, such as,
e.g. bicarbonate brine solution may be produced, modified, and/or
stored.
[0623] For the systems where the carbon from the source of carbon
is contacted with the cathode electrolyte inside the cathode
chamber, the cathode electrolyte containing alkali, bicarbonate,
and/or carbonate may be withdrawn from the cathode chamber and may
be contacted with alkaline earth metal ions, as described herein,
to form bicarbonate/carbonate products.
Components of Electrochemical Cell
[0624] The methods and systems provided herein include one or more
of the following components.
[0625] In some embodiments, the anode may contain a corrosion
stable, electrically conductive base support. Such as, but not
limited to, amorphous carbon, such as carbon black, fluorinated
carbons like the specifically fluorinated carbons described in U.S.
Pat. No. 4,908,198 and available under the trademark SFC.TM.
carbons. Other examples of electrically conductive base materials
include, but not limited to, sub-stoichiometric titanium oxides,
such as, Magneli phase sub-stoichiometric titanium oxides having
the formula TiO.sub.x wherein x ranges from about 1.67 to about
1.9. For example, titanium oxide Ti.sub.4O.sub.7. In some
embodiments, carbon based materials provide a mechanical support
for the GDE or as blending materials to enhance electrical
conductivity but may not be used as catalyst support to prevent
corrosion.
[0626] In some embodiments, the gas-diffusion electrodes or general
electrodes described herein contain an electrocatalyst for aiding
in electrochemical dissociation, e.g. reduction of oxygen at the
cathode. Examples of electrocatalysts include, but not limited to,
highly dispersed metals or alloys of the platinum group metals,
such as platinum, palladium, ruthenium, rhodium and iridium (e.g.
titanium mesh coated with PtIr mixed metal oxide or titanium coated
with galvanized platinum); electrocatalytic metal oxides;
organometallic macrocyclic compounds, and other electrocatalysts
well known in the art for electrochemical reduction of oxygen.
[0627] In some embodiments, the electrodes described herein, relate
to porous homogeneous composite structures as well as
heterogeneous, layered type composite structures wherein each layer
may have a distinct physical and compositional make-up, e.g.
porosity and electroconductive base to prevent flooding, and loss
of the three phase interface, and resulting electrode
performance.
[0628] The electrodes provided herein may include anodes and
cathodes having porous polymeric layers on or adjacent to the
anolyte or catholyte solution side of the electrode which may
assist in decreasing penetration and electrode fouling. Stable
polymeric resins or films may be included in a composite electrode
layer adjacent to the anolyte comprising resins formed from
non-ionic polymers, such as polystyrene, polyvinyl chloride,
polysulfone, etc., or ionic-type charged polymers like those formed
from polystyrenesulfonic acid, sulfonated copolymers of styrene and
vinylbenzene, carboxylated polymer derivatives, sulfonated or
carboxylated polymers having partially or totally fluorinated
hydrocarbon chains and aminated polymers like polyvinylpyridine.
Stable microporous polymer films may also be included on the dry
side to inhibit electrolyte penetration. In some embodiments, the
gas-diffusion cathodes includes such cathodes known in the art that
are coated with high surface area coatings of precious metals such
as gold and/or silver, precious metal alloys, nickel, and the
like.
[0629] In some embodiments, the electrolyte including the catholyte
or the cathode electrolyte and/or the anolyte or the anode
electrolyte, or the third electrolyte disposed between AEM and CEM,
in the systems and methods provided herein include, but not limited
to, saltwater or fresh water. The saltwater includes, but is not
limited to, seawater, brine, and/or brackish water. In some
embodiments, the cathode electrolyte in the systems and methods
provided herein include, but not limited to, seawater, freshwater,
brine, brackish water, hydroxide, such as, sodium hydroxide, or
combination thereof "Saltwater" is employed in its conventional
sense to refer to a number of different types of aqueous fluids
other than fresh water, where the term "saltwater" includes, but is
not limited to, brackish water, sea water and brine (including,
naturally occurring subterranean brines or anthropogenic
subterranean brines and man-made brines, e.g., geothermal plant
wastewaters, desalination waste waters, etc), as well as other
salines having a salinity that is greater than that of freshwater.
Brine is water saturated or nearly saturated with salt and has a
salinity that is 50 ppt (parts per thousand) or greater. Brackish
water is water that is saltier than fresh water, but not as salty
as seawater, having a salinity ranging from 0.5 to 35 ppt. Seawater
is water from a sea or ocean and has a salinity ranging from 35 to
50 ppt. The saltwater source may be a naturally occurring source,
such as a sea, ocean, lake, swamp, estuary, lagoon, etc., or a
man-made source. In some embodiments, the systems provided herein
include the saltwater from terrestrial brine. In some embodiments,
the depleted saltwater withdrawn from the electrochemical cells is
replenished with salt and re-circulated back in the electrochemical
cell.
[0630] In some embodiments, the electrolyte including the cathode
electrolyte and/or the anode electrolyte and/or the third
electrolyte, such as, saltwater includes water containing more than
1% chloride content, such as, NaCl; or more than 10% NaCl; or more
than 20% NaCl; or more than 30% NaCl; or more than 40% NaCl; or
more than 50% NaCl; or more than 60% NaCl; or more than 70% NaCl;
or more than 80% NaCl; or more than 90% NaCl; or between 1-99%
NaCl; or between 1-95% NaCl; or between 1-90% NaCl; or between
1-80% NaCl; or between 1-70% NaCl; or between 1-60% NaCl; or
between 1-50% NaCl; or between 1-40% NaCl; or between 1-30% NaCl;
or between 1-20% NaCl; or between 1-10% NaCl; or between 10-99%
NaCl; or between 10-95% NaCl; or between 10-90% NaCl; or between
10-80% NaCl; or between 10-70% NaCl; or between 10-60% NaCl; or
between 10-50% NaCl; or between 10-40% NaCl; or between 10-30%
NaCl; or between 10-20% NaCl; or between 20-99% NaCl; or between
20-95% NaCl; or between 20-90% NaCl; or between 20-80% NaCl; or
between 20-70% NaCl; or between 20-60% NaCl; or between 20-50%
NaCl; or between 20-40% NaCl; or between 20-30% NaCl; or between
30-99% NaCl; or between 30-95% NaCl; or between 30-90% NaCl; or
between 30-80% NaCl; or between 30-70% NaCl; or between 30-60%
NaCl; or between 30-50% NaCl; or between 30-40% NaCl; or between
40-99% NaCl; or between 40-95% NaCl; or between 40-90% NaCl; or
between 40-80% NaCl; or between 40-70% NaCl; or between 40-60%
NaCl; or between 40-50% NaCl; or between 50-99% NaCl; or between
50-95% NaCl; or between 50-90% NaCl; or between 50-80% NaCl; or
between 50-70% NaCl; or between 50-60% NaCl; or between 60-99%
NaCl; or between 60-95% NaCl; or between 60-90% NaCl; or between
60-80% NaCl; or between 60-70% NaCl; or between 70-99% NaCl; or
between 70-95% NaCl; or between 70-90% NaCl; or between 70-80%
NaCl; or between 80-99% NaCl; or between 80-95% NaCl; or between
80-90% NaCl; or between 90-99% NaCl; or between 90-95% NaCl. In
some embodiments, the above recited percentages apply to ammonium
chloride, ferric chloride, sodium bromide, sodium iodide, or sodium
sulfate as an electrolyte. The percentages recited herein include
wt % or wt/wt % or wt/v %. It is to be understood that all the
electrochemical systems described herein that contain sodium
chloride can be replaced with other suitable electrolytes, such as,
but not limited to, ammonium chloride, sodium bromide, sodium
iodide, sodium sulfate, or combination thereof.
[0631] In some embodiments, the cathode electrolyte, such as,
saltwater, fresh water, and/or sodium hydroxide do not include
alkaline earth metal ions or divalent cations. As used herein, the
divalent cations include alkaline earth metal ions, such as but not
limited to, calcium, magnesium, barium, strontium, radium, etc. In
some embodiments, the cathode electrolyte, such as, saltwater,
fresh water, and/or sodium hydroxide include less than 1% w/w
divalent cations. In some embodiments, the cathode electrolyte,
such as, seawater, freshwater, brine, brackish water, and/or sodium
hydroxide include less than 1% w/w divalent cations. In some
embodiments, the cathode electrolyte, such as, seawater,
freshwater, brine, brackish water, and/or sodium hydroxide include
divalent cations including, but not limited to, calcium, magnesium,
and combination thereof. In some embodiments, the cathode
electrolyte, such as, seawater, freshwater, brine, brackish water,
and/or sodium hydroxide include less than 1% w/w divalent cations
including, but not limited to, calcium, magnesium, and combination
thereof.
[0632] In some embodiments, the cathode electrolyte, such as,
seawater, freshwater, brine, brackish water, and/or sodium
hydroxide include less than 1% w/w; or less than 5% w/w; or less
than 10% w/w; or less than 15% w/w; or less than 20% w/w; or less
than 25% w/w; or less than 30% w/w; or less than 40% w/w; or less
than 50% w/w; or less than 60% w/w; or less than 70% w/w; or less
than 80% w/w; or less than 90% w/w; or less than 95% w/w; or
between 0.05-1% w/w; or between 0.5-1% w/w; or between 0.5-5% w/w;
or between 0.5-10% w/w; or between 0.5-20% w/w; or between 0.5-30%
w/w; or between 0.5-40% w/w; or between 0.5-50% w/w; or between
0.5-60% w/w; or between 0.5-70% w/w; or between 0.5-80% w/w; or
between 0.5-90% w/w; or between 5-8% w/w; or between 5-10% w/w; or
between 5-20% w/w; or between 5-30% w/w; or between 5-40% w/w; or
between 5-50% w/w; or between 5-60% w/w; or between 5-70% w/w; or
between 5-80% w/w; or between 5-90% w/w; or between 10-20% w/w; or
between 10-30% w/w; or between 10-40% w/w; or between 10-50% w/w;
or between 10-60% w/w; or between 10-70% w/w; or between 10-80%
w/w; or between 10-90% w/w; or between 30-40% w/w; or between
30-50% w/w; or between 30-60% w/w; or between 30-70% w/w; or
between 30-80% w/w; or between 30-90% w/w; or between 50-60% w/w;
or between 50-70% w/w; or between 50-80% w/w; or between 50-90%
w/w; or between 75-80% w/w; or between 75-90% w/w; or between
80-90% w/w; or between 90-95% w/w; of divalent cations including,
but not limited to, calcium, magnesium, and combination
thereof.
[0633] In some embodiments, the cathode electrolyte includes, but
not limited to, sodium hydroxide, sodium bicarbonate, sodium
carbonate, or combination thereof. In some embodiments, the cathode
electrolyte includes, but not limited to, sodium or potassium
hydroxide. In some embodiments, the cathode electrolyte includes,
but not limited to, sodium hydroxide, divalent cations, or
combination thereof. In some embodiments, the cathode electrolyte
includes, but not limited to, sodium hydroxide, sodium bicarbonate,
sodium carbonate, divalent cations, or combination thereof. In some
embodiments, the cathode electrolyte includes, but not limited to,
sodium hydroxide, calcium bicarbonate, calcium carbonate, magnesium
bicarbonate, magnesium carbonate, calcium magnesium carbonate, or
combination thereof. In some embodiments, the cathode electrolyte
includes, but not limited to, saltwater, sodium hydroxide,
bicarbonate brine solution, or combination thereof. In some
embodiments, the cathode electrolyte includes, but not limited to,
saltwater and sodium hydroxide. In some embodiments, the cathode
electrolyte includes, but not limited to, fresh water and sodium
hydroxide. In some embodiments, the cathode electrolyte includes
fresh water devoid of alkalinity or divalent cations. In some
embodiments, the cathode electrolyte includes, but not limited to,
fresh water, sodium hydroxide, sodium bicarbonate, sodium
carbonate, divalent cations, or combination thereof.
[0634] In some embodiments, the anode electrolyte includes, but not
limited to, fresh water and metal ions. In some embodiments, the
anode electrolyte includes, but not limited to, saltwater and metal
ions. In some embodiments, the anode electrolyte includes metal ion
solution.
[0635] In some embodiments, the depleted saltwater from the cell
may be circulated back to the cell. In some embodiments, the
cathode electrolyte includes 1-90%; 1-50%; or 1-40%; or 1-30%; or
1-15%; or 1-20%; or 1-10%; or 5-90%; or 5-50%; or 5-40%; or 5-30%;
or 5-20%; or 5-10%; or 10-90%; or 10-50%; or 10-40%; or 10-30%; or
10-20%; or 15-20%; or 15-30%; or 20-30%, of the sodium hydroxide
solution. In some embodiments, the anode electrolyte includes 0-5
M; or 0-4.5M; or 0-4M; or 0-3.5M; or 0-3M; or 0-2.5M; or 0-2M; or
0-1.5M; or 0-1M; or 1-5M; or 1-4.5M; or 1-4M; or 1-3.5M; or 1-3M;
or 1-2.5M; or 1-2M; or 1-1.5M; or 2-5M; or 2-4.5M; or 2-4M; or
2-3.5M; or 2-3M; or 2-2.5M; or 3-5M; or 3-4.5M; or 3-4M; or 3-3.5M;
or 4-5M; or 4.5-5M metal ion solution. In some embodiments, the
anode does not form an oxygen gas. In some embodiments, the anode
does not form a chlorine gas.
[0636] In some embodiments, the cathode electrolyte and the anode
electrolyte are separated in part or in full by an ion exchange
membrane. In some embodiments, the ion exchange membrane is an
anion exchange membrane or a cation exchange membrane. In some
embodiments, the cation exchange membranes in the electrochemical
cell, as disclosed herein, are conventional and are available from,
for example, Asahi Kasei of Tokyo, Japan; or from Membrane
International of Glen Rock, N.J., or DuPont, in the USA. Examples
of CEM include, but are not limited to, N2030WX (Dupont),
F8020/F8080 (Flemion), and F6801 (Aciplex). CEMs that are desirable
in the methods and systems of the invention have minimal resistance
loss, greater than 90% selectivity, and high stability in
concentrated caustic. AEMs, in the methods and systems of the
invention are exposed to concentrated metallic salt anolytes and
saturated brine stream. It is desirable for the AEM to allow
passage of salt ion such as chloride ion to the anolyte but reject
the metallic ion species from the anolyte. In some embodiments,
metallic salts may form various ion species (cationic, anionic,
and/or neutral) including but not limited to, MCl.sup.+,
MCl.sub.2.sup.-, MCl.sub.2.degree., M.sup.2+ etc. and it is
desirable for such complexes to not pass through AEM or not foul
the membranes. Provided in the examples are some of the membranes
that have been tested for the methods and systems of the invention
that have been found to prevent metal crossover.
[0637] Accordingly, provided herein are methods comprising
contacting an anode with a metal ion in an anode electrolyte in an
anode chamber; converting the metal ion from a lower oxidation
state to a higher oxidation state at the anode; contacting a
cathode with a cathode electrolyte in a cathode chamber; forming an
alkali, water, or hydrogen gas at the cathode; and preventing
migration of the metal ions from the anode electrolyte to the
cathode electrolyte by using an anion exchange membrane wherein the
anion exchange membrane has an ohmic resistance of less than 3
.OMEGA.cm.sup.2 or less than 2 .OMEGA.cm.sup.2 or less than 1
.OMEGA.cm.sup.2. In some embodiments, the anion exchange membrane
has an ohmic resistance of between 1-3 .OMEGA.cm.sup.2. In some
embodiments, there are provided methods comprising contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
converting the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a cathode with a cathode
electrolyte in a cathode chamber; forming an alkali, water, or
hydrogen gas at the cathode; and preventing migration of the metal
ions from the anode electrolyte to the cathode electrolyte by using
an anion exchange membrane wherein the anion exchange membrane
rejects more than 80%, or more than 90%, or more than 99%, or about
99.9% of all metal ions from the anode electrolyte.
[0638] There are also provided systems comprising an anode in
contact with a metal ion in an anode electrolyte in an anode
chamber wherein the anode is configured to convert the metal ion
from a lower oxidation state to a higher oxidation state in the
anode chamber; a cathode in contact with a cathode electrolyte in a
cathode chamber wherein the cathode is configured to form an
alkali, water, or hydrogen gas in the cathode chamber; and an anion
exchange membrane wherein the anion exchange membrane has an ohmic
resistance of less than 3 .OMEGA.cm.sup.2 or less than 2
.OMEGA.cm.sup.2 or less than 1 .OMEGA.cm.sup.2. In some
embodiments, the anion exchange membrane has an ohmic resistance of
between 1-3 .OMEGA.cm.sup.2. In some embodiments, there are
provided systems comprising contacting an anode in contact with a
metal ion in an anode electrolyte in an anode chamber wherein the
anode is configured to convert the metal ion from a lower oxidation
state to a higher oxidation state in the anode chamber; a cathode
in contact with a cathode electrolyte in a cathode chamber wherein
the cathode is configured to form an alkali, water, or hydrogen gas
in the cathode chamber; and an anion exchange membrane wherein the
anion exchange membrane rejects more than 80%, or more than 90%, or
more than 99%, or about 99.9% of all metal ions from the anode
electrolyte.
[0639] Also provided herein are methods comprising contacting an
anode with a metal ion in an anode electrolyte in an anode chamber;
converting the metal ion from a lower oxidation state to a higher
oxidation state at the anode; contacting a cathode with a cathode
electrolyte in a cathode chamber; forming an alkali at the cathode;
separating the anode electrolyte from a brine compartment with an
anion exchange membrane; separating the cathode electrolyte from
the brine compartment by a cation exchange membrane; and preventing
migration of the metal ions from the anode electrolyte to the brine
compartment by using the anion exchange membrane that has an ohmic
resistance of less than 3 .OMEGA.cm.sup.2 or less than 2
.OMEGA.cm.sup.2 or less than 1 .OMEGA.cm.sup.2. In some
embodiments, the anion exchange membrane has an ohmic resistance of
between 1-3 .OMEGA.cm.sup.2. In some embodiments, there are
provided methods comprising contacting an anode with a metal ion in
an anode electrolyte in an anode chamber; converting the metal ion
from a lower oxidation state to a higher oxidation state at the
anode; contacting a cathode with a cathode electrolyte in a cathode
chamber; forming an alkali at the cathode; separating the anode
electrolyte from a brine compartment with an anion exchange
membrane; separating the cathode electrolyte from the brine
compartment by a cation exchange membrane; and preventing migration
of the metal ions from the anode electrolyte to the brine
compartment by using the anion exchange membrane that rejects more
than 80%, or more than 90%, or more than 99%, or about 99.9% of all
metal ions from the anode electrolyte.
[0640] There are also provided systems comprising an anode in
contact with a metal ion in an anode electrolyte in an anode
chamber wherein the anode is configured to convert the metal ion
from a lower oxidation state to a higher oxidation state in the
anode chamber; a cathode in contact with a cathode electrolyte in a
cathode chamber wherein the cathode is configured to form an alkali
in the cathode chamber; an anion exchange membrane separating the
anode electrolyte from a brine compartment; and a cation exchange
membrane separating the cathode electrolyte from the brine
compartment, wherein the anion exchange membrane has an ohmic
resistance of less than 3 .OMEGA.cm.sup.2 or less than 2
.OMEGA.cm.sup.2 or less than 1 .OMEGA.cm.sup.2. In some
embodiments, the anion exchange membrane has an ohmic resistance of
between 1-3 .OMEGA.cm.sup.2. In some embodiments, there are
provided systems comprising contacting an anode in contact with a
metal ion in an anode electrolyte in an anode chamber wherein the
anode is configured to convert the metal ion from a lower oxidation
state to a higher oxidation state in the anode chamber; a cathode
in contact with a cathode electrolyte in a cathode chamber wherein
the cathode is configured to form an alkali in the cathode chamber;
an anion exchange membrane separating the anode electrolyte from a
brine compartment; and a cation exchange membrane separating the
cathode electrolyte from the brine compartment, wherein the anion
exchange membrane rejects more than 80%, or more than 90%, or more
than 99%, or about 99.9% of all metal ions from the anode
electrolyte.
[0641] The methods and systems described above comprising the AEM
further include the treatment of the anode electrolyte comprising
the metal ion in the higher oxidation state with the hydrogen gas,
unsaturated hydrocarbon, or saturated hydrocarbon, as described
herein.
[0642] Examples of cationic exchange membranes include, but not
limited to, cationic membrane consisting of a perfluorinated
polymer containing anionic groups, for example sulphonic and/or
carboxylic groups. However, it may be appreciated that in some
embodiments, depending on the need to restrict or allow migration
of a specific cation or an anion species between the electrolytes,
a cation exchange membrane that is more restrictive and thus allows
migration of one species of cations while restricting the migration
of another species of cations may be used as, e.g., a cation
exchange membrane that allows migration of sodium ions into the
cathode electrolyte from the anode electrolyte while restricting
migration of other ions from the anode electrolyte into the cathode
electrolyte, may be used. Similarly, in some embodiments, depending
on the need to restrict or allow migration of a specific anion
species between the electrolytes, an anion exchange membrane that
is more restrictive and thus allows migration of one species of
anions while restricting the migration of another species of anions
may be used as, e.g., an anion exchange membrane that allows
migration of chloride ions into the anode electrolyte from the
cathode electrolyte while restricting migration of hydroxide ions
from the cathode electrolyte into the anode electrolyte, may be
used. Such restrictive cation and/or anion exchange membranes are
commercially available and can be selected by one ordinarily
skilled in the art.
[0643] In some embodiments, there is provided a system comprising
one or more anion exchange membrane, and cation exchange membranes
located between the anode and the cathode. In some embodiments, the
membranes should be selected such that they can function in an
acidic and/or basic electrolytic solution as appropriate. Other
desirable characteristics of the membranes include high ion
selectivity, low ionic resistance, high burst strength, and high
stability in an acidic electrolytic solution in a temperature range
of 0.degree. C. to 100.degree. C. or higher, or a alkaline solution
in similar temperature range may be used. In some embodiments, it
is desirable that the ion exchange membrane prevents the transport
of the metal ion from the anolyte to the catholyte. In some
embodiments, a membrane that is stable in the range of 0.degree. C.
to 90.degree. C.; or 0.degree. C. to 80.degree. C.; or 0.degree. C.
to 70.degree. C.; or 0.degree. C. to 60.degree. C.; or 0.degree. C.
to 50.degree. C.; or 0.degree. C. to 40.degree. C., or 0.degree. C.
to 30.degree. C., or 0.degree. C. to 20.degree. C., or 0.degree. C.
to 10.degree. C., or higher may be used. In some embodiments, a
membrane that is stable in the range of 0.degree. C. to 90.degree.
C.; or 0.degree. C. to 80.degree. C.; or 0.degree. C. to 70.degree.
C.; or 0.degree. C. to 60.degree. C.; or 0.degree. C. to 50.degree.
C.; or 0.degree. C. to 40.degree. C., but unstable at higher
temperature, may be used. For other embodiments, it may be useful
to utilize an ion-specific ion exchange membranes that allows
migration of one type of cation but not another; or migration of
one type of anion and not another, to achieve a desired product or
products in an electrolyte. In some embodiments, the membrane may
be stable and functional for a desirable length of time in the
system, e.g., several days, weeks or months or years at
temperatures in the range of 0.degree. C. to 90.degree. C.; or
0.degree. C. to 80.degree. C.; or 0.degree. C. to 70.degree. C.; or
0.degree. C. to 60.degree. C.; or 0.degree. C. to 50.degree. C.; or
0.degree. C. to 40.degree. C.; or 0.degree. C. to 30.degree. C.; or
0.degree. C. to 20.degree. C.; or 0.degree. C. to 10.degree. C.,
and higher and/or lower. In some embodiments, for example, the
membranes may be stable and functional for at least 1 day, at least
5 days, 10 days, 15 days, 20 days, 100 days, 1000 days, 5-10 years,
or more in electrolyte temperatures at 100.degree. C., 90.degree.
C., 80.degree. C., 70.degree. C., 60.degree. C., 50.degree. C.,
40.degree. C., 30.degree. C., 20.degree. C., 10.degree. C.,
5.degree. C. and more or less.
[0644] The ohmic resistance of the membranes may affect the voltage
drop across the anode and cathode, e.g., as the ohmic resistance of
the membranes increase, the voltage across the anode and cathode
may increase, and vice versa. Membranes that can be used include,
but are not limited to, membranes with relatively low ohmic
resistance and relatively high ionic mobility; and membranes with
relatively high hydration characteristics that increase with
temperatures, and thus decreasing the ohmic resistance. By
selecting membranes with lower ohmic resistance known in the art,
the voltage drop across the anode and the cathode at a specified
temperature can be lowered.
[0645] Scattered through membranes may be ionic channels including
acid groups. These ionic channels may extend from the internal
surface of the matrix to the external surface and the acid groups
may readily bind water in a reversible reaction as
water-of-hydration. This binding of water as water-of-hydration may
follow first order reaction kinetics, such that the rate of
reaction is proportional to temperature. Consequently, membranes
can be selected to provide a relatively low ohmic and ionic
resistance while providing for improved strength and resistance in
the system for a range of operating temperatures.
[0646] In some embodiments, the carbon from the source of carbon,
when contacted with the cathode electrolyte inside the cathode
chamber, reacts with the hydroxide ions and produces water and
carbonate ions, depending on the pH of the cathode electrolyte. The
addition of the carbon from the source of carbon to the cathode
electrolyte may lower the pH of the cathode electrolyte. Thus,
depending on the degree of alkalinity desired in the cathode
electrolyte, the pH of the cathode electrolyte may be adjusted and
in some embodiments is maintained between 6 and 12; between 7 and
14 or greater; or between 7 and 13; or between 7 and 12; or between
7 and 11; or between 7 and 10; or between 7 and 9; or between 7 and
8; or between 8 and 14 or greater; or between 8 and 13; or between
8 and 12; or between 8 and 11; or between 8 and 10; or between 8
and 9; or between 9 and 14 or greater; or between 9 and 13; or
between 9 and 12; or between 9 and 11; or between 9 and 10; or
between 10 and 14 or greater; or between 10 and 13; or between 10
and 12; or between 10 and 11; or between 11 and 14 or greater; or
between 11 and 13; or between 11 and 12; or between 12 and 14 or
greater; or between 12 and 13; or between 13 and 14 or greater. In
some embodiments, the pH of the cathode electrolyte may be adjusted
to any value between 7 and 14 or greater, a pH less than 12, a pH
7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5,
13.0, 13.5, 14.0, and/or greater.
[0647] Similarly, in some embodiments of the system, the pH of the
anode electrolyte is adjusted and is maintained between 0-7; or
between 0-6; or between 0-5; or between 0-4; or between 0-3; or
between 0-2; or between 0-1. As the voltage across the anode and
cathode may be dependent on several factors including the
difference in pH between the anode electrolyte and the cathode
electrolyte (as can be determined by the Nernst equation well known
in the art), in some embodiments, the pH of the anode electrolyte
may be adjusted to a value between 0 and 7, including 0, 0.5, 1.0,
1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5 and 7,
depending on the desired operating voltage across the anode and
cathode. Thus, in equivalent systems, where it is desired to reduce
the energy used and/or the voltage across the anode and cathode,
e.g., as in the chlor-alkali process, the carbon from the source of
carbon can be added to the cathode electrolyte as disclosed herein
to achieve a desired pH difference between the anode electrolyte
and cathode electrolyte.
[0648] The system may be configured to produce any desired pH
difference between the anode electrolyte and the cathode
electrolyte by modulating the pH of the anode electrolyte, the pH
of the cathode electrolyte, the concentration of hydroxide in the
cathode electrolyte, the withdrawal and replenishment of the anode
electrolyte, the withdrawal and replenishment of the cathode
electrolyte, and/or the amount of the carbon from the source of
carbon added to the cathode electrolyte. By modulating the pH
difference between the anode electrolyte and the cathode
electrolyte, the voltage across the anode and the cathode can be
modulated. In some embodiments, the system is configured to produce
a pH difference of at least 4 pH units; at least 5 pH units; at
least 6 pH units; at least 7 pH units; at least 8 pH units; at
least 9 pH units; at least 10 pH units; at least 11 pH units; at
least 12 pH units; at least 13 pH units; at least 14 pH units; or
between 4-12 pH units; or between 4-11 pH units; or between 4-10 pH
units; or between 4-9 pH units; or between 4-8 pH units; or between
4-7 pH units; or between 4-6 pH units; or between 4-5 pH units; or
between 3-12 pH units; or between 3-11 pH units; or between 3-10 pH
units; or between 3-9 pH units; or between 3-8 pH units; or between
3-7 pH units; or between 3-6 pH units; or between 3-5 pH units; or
between 3-4 pH units; or between 5-12 pH units; or between 5-11 pH
units; or between 5-10 pH units; or between 5-9 pH units; or
between 5-8 pH units; or between 5-7 pH units; or between 5-6 pH
units; or between 6-12 pH units; or between 6-11 pH units; or
between 6-10 pH units; or between 6-9 pH units; or between 6-8 pH
units; or between 6-7 pH units; or between 7-12 pH units; or
between 7-11 pH units; or between 7-10 pH units; or between 7-9 pH
units; or between 7-8 pH units; or between 8-12 pH units; or
between 8-11 pH units; or between 8-10 pH units; or between 8-9 pH
units; or between 9-12 pH units; or between 9-11 pH units; or
between 9-10 pH units; or between 10-12 pH units; or between 10-11
pH units; or between 11-12 pH units; between the anode electrolyte
and the cathode electrolyte. In some embodiments, the system is
configured to produce a pH difference of at least 4 pH units
between the anode electrolyte and the cathode electrolyte.
[0649] In some embodiments, the anode electrolyte and the cathode
electrolyte in the electrochemical cell, in the methods and systems
provided herein, are operated at room temperature or at elevated
temperatures, such as, e.g., at more than 40.degree. C., or more
than 50.degree. C., or more than 60.degree. C., or more than
70.degree. C., or more than 80.degree. C., or between 30-70.degree.
C.
Production of Bicarbonate and/or Carbonate Products
[0650] In some embodiments, the methods and systems provided herein
are configured to process the carbonate/bicarbonate solution
obtained after the cathode electrolyte is contacted with the carbon
from the source of carbon. In some embodiments, the carbonate
and/or bicarbonate containing solution is treated with divalent
cations, such as but not limited to, calcium and/or magnesium to
form calcium and/or magnesium carbonate and/or bicarbonate. An
illustrative embodiment for such processes is provided in FIG.
13.
[0651] As illustrated in FIG. 13, process 1300 illustrates methods
and systems to process the carbonate/bicarbonate solution obtained
after the cathode electrolyte is contacted with the carbon from the
source of carbon. In some embodiments, the solution is subjected to
the precipitation in the precipitator 1301. In some embodiments,
the solution includes sodium hydroxide, sodium carbonate, and/or
sodium bicarbonate. In some embodiments, the system is configured
to treat bicarbonate and/or carbonate ions in the cathode
electrolyte with an alkaline earth metal ion or divalent cation
including, but not limited to, calcium, magnesium, and combination
thereof. The "divalent cation" as used herein, includes any solid
or solution that contains divalent cations, such as, alkaline earth
metal ions or any aqueous medium containing alkaline earth metals.
The alkaline earth metals include calcium, magnesium, strontium,
barium, etc. or combinations thereof. The divalent cations (e.g.,
alkaline earth metal cations such as Ca.sup.2+ and Mg.sup.2+) may
be found in industrial wastes, seawater, brines, hard water,
minerals, and many other suitable sources. The
alkaline-earth-metal-containing water includes fresh water or
saltwater, depending on the method employing the water. In some
embodiments, the water employed in the process includes one or more
alkaline earth metals, e.g., magnesium, calcium, etc. In some
embodiments, the alkaline earth metal ions are present in an amount
of 1% to 99% by wt; or 1% to 95% by wt; or 1% to 90% by wt; or 1%
to 80% by wt; or 1% to 70% by wt; or 1% to 60% by wt; or 1% to 50%
by wt; or 1% to 40% by wt; or 1% to 30% by wt; or 1% to 20% by wt;
or 1% to 10% by wt; or 20% to 95% by wt; or 20% to 80% by wt; or
20% to 50% by wt; or 50% to 95% by wt; or 50% to 80% by wt; or 50%
to 75% by wt; or 75% to 90% by wt; or 75% to 80% by wt; or 80% to
90% by wt of the solution containing the alkaline earth metal ions.
In some embodiments, the alkaline earth metal ions are present in
saltwater, such as, seawater. In some embodiments, the source of
divalent cations is hard water or naturally occurring hard brines.
In some embodiments, calcium rich waters may be combined with
magnesium silicate minerals, such as olivine or serpentine.
[0652] In some embodiments, gypsum (e.g. from Solvay process)
provides a source of divalent cation such as, but not limited to,
calcium ions. After the precipitation of the calcium
carbonate/bicarbonate using the carbonate/bicarbonate solution from
the cathode chamber and the calcium from gypsum, the supernatant
containing sodium sulfate may be circulated to the electrochemical
systems described herein. The sodium sulfate solution may be used
in combination with metal sulfate such as copper sulfate such the
Cu(I) ions are oxidized to Cu (II) ions in the anode chamber and
are used further for the sulfonation of hydrogen gases or for the
sulfonation of unsaturated or saturated hydrocarbons. In such
embodiments, the electrochemical system is fully integrated with
the precipitation process. Such use of gypsum as a source of
calcium is described in U.S. Provisional Application No.
61/514,879, filed Aug. 3, 2011, which is fully incorporate herein
by reference in its entirety.
[0653] In some locations, industrial waste streams from various
industrial processes provide for convenient sources of cations (as
well as in some cases other materials useful in the process, e.g.,
metal hydroxide). Such waste streams include, but are not limited
to, mining wastes; fossil fuel burning ash (e.g., fly ash, bottom
ash, boiler slag); slag (e.g., iron slag, phosphorous slag); cement
kiln waste (e.g., cement kiln dust); oil refinery/petrochemical
refinery waste (e.g., oil field and methane seam brines); coal seam
wastes (e.g., gas production brines and coal seam brine); paper
processing waste; water softening waste brine (e.g., ion exchange
effluent); silicon processing wastes; agricultural waste; metal
finishing waste; high pH textile waste; and caustic sludge. In some
embodiments, the aqueous solution of cations include calcium and/or
magnesium in amounts ranging from 10-50,000 ppm; or 10-10,000 ppm;
or 10-5,000 ppm; or 10-1,000 ppm; or 10-100 ppm; or 50-50,000 ppm;
or 50-10,000 ppm; or 50-1,000 ppm; or 50-100 ppm; or 100-50,000
ppm; or 100-10,000 ppm; or 100-1,000 ppm; or 100-500 ppm; or
1,000-50,000 ppm; or 1,000-10,000 ppm; or 5,000-50,000 ppm; or
5,000-10,000 ppm; or 10,000-50,000 ppm.
[0654] Freshwater may be a convenient source of cations (e.g.,
cations of alkaline earth metals such as Ca.sup.2+ and Mg.sup.2+).
Any number of suitable freshwater sources may be used, including
freshwater sources ranging from sources relatively free of minerals
to sources relatively rich in minerals. Mineral-rich freshwater
sources may be naturally occurring, including any of a number of
hard water sources, lakes, or inland seas. Some mineral-rich
freshwater sources such as alkaline lakes or inland seas (e.g.,
Lake Van in Turkey) also provide a source of pH-modifying agents.
Mineral-rich freshwater sources may also be anthropogenic. For
example, a mineral-poor (soft) water may be contacted with a source
of cations such as alkaline earth metal cations (e.g., Ca.sup.2+,
Mg.sup.2+, etc.) to produce a mineral-rich water that is suitable
for methods and systems described herein. Cations or precursors
thereof (e.g., salts, minerals) may be added to freshwater (or any
other type of water described herein) using any convenient protocol
(e.g., addition of solids, suspensions, or solutions). In some
embodiments, divalent cations selected from Ca.sup.2+ and Mg.sup.2+
are added to freshwater. In some embodiments, freshwater containing
Ca.sup.2+ is combined with magnesium silicates (e.g., olivine or
serpentine), or products or processed forms thereof, yielding a
solution comprising calcium and magnesium cations.
[0655] The precipitate obtained after the contacting of the carbon
from the source of carbon with the cathode electrolyte and the
divalent cations includes, but is not limited to, calcium
carbonate, magnesium carbonate, calcium bicarbonate, magnesium
bicarbonate, calcium magnesium carbonate, or combination thereof.
In some embodiments, the precipitate may be subjected to one or
more of steps including, but not limited to, mixing, stirring,
temperature, pH, precipitation, residence time of the precipitate,
dewatering of precipitate, washing precipitate with water, ion
ratio, concentration of additives, drying, milling, grinding,
storing, aging, and curing, to make the carbonate composition of
the invention. In some embodiments, the precipitation conditions
are such that the carbonate products are metastable forms, such as,
but not limited to vaterite, aragonite, amorphous calcium
carbonate, or combination thereof.
[0656] The precipitator 1301 can be a tank or a series of tanks.
Contact protocols include, but are not limited to, direct
contacting protocols, e.g., flowing the volume of water containing
cations, e.g. alkaline earth metal ions through the volume of
cathode electrolyte containing sodium hydroxide; concurrent
contacting means, e.g., contact between unidirectionally flowing
liquid phase streams; and countercurrent means, e.g., contact
between oppositely flowing liquid phase streams, and the like.
Thus, contact may be accomplished through use of infusers,
bubblers, fluidic Venturi reactor, sparger, gas filter, spray,
tray, or packed column reactors, and the like, as may be
convenient. In some embodiments, the contact is by spray. In some
embodiments, the contact is through packed column. In some
embodiments, the carbon from the source of carbon is added to the
source of cations and the cathode electrolyte containing hydroxide.
In some embodiments, the source of cations and the cathode
electrolyte containing alkali is added to the carbon from the
source of carbon. In some embodiments, both the source of cations
and the carbon from the source of carbon are simultaneously added
to the cathode electrolyte containing alkali in the precipitator
for precipitation.
[0657] In some embodiments, where the carbon from the source of
carbon has been added to the cathode electrolyte inside the cathode
chamber, the withdrawn cathode electrolyte including hydroxide,
bicarbonate and/or carbonate is administered to the precipitator
for further reaction with the divalent cations. In some
embodiments, where the carbon from the source of carbon and the
divalent cations have been added to the cathode electrolyte inside
the cathode chamber, the withdrawn cathode electrolyte including
sodium hydroxide, calcium carbonate, magnesium carbonate, calcium
bicarbonate, magnesium bicarbonate, calcium magnesium carbonate, or
combination thereof, is administered to the precipitator for
further processing.
[0658] The precipitator 1301 containing the solution of calcium
carbonate, magnesium carbonate, calcium bicarbonate, magnesium
bicarbonate, calcium magnesium carbonate, or combination thereof is
subjected to precipitation conditions. At precipitation step,
carbonate compounds, which may be amorphous or crystalline, are
precipitated. These carbonate compounds may form a reaction product
including carbonic acid, bicarbonate, carbonate, or mixture
thereof. The carbonate precipitate may be the self-cementing
composition and may be stored as is in the mother liquor or may be
further processed to make the cement products. Alternatively, the
precipitate may be subjected to further processing to give the
hydraulic cement or the supplementary cementitious materials (SCM)
compositions. The self-cementing compositions, hydraulic cements,
and SCM have been described in U.S. application Ser. No.
12/857,248, filed 16 Aug. 2010, which is incorporated herein by
reference in its entirety in the present disclosure.
[0659] The one or more conditions or one or more precipitation
conditions of interest include those that change the physical
environment of the water to produce the desired precipitate
product. Such one or more conditions or precipitation conditions
include, but are not limited to, one or more of temperature, pH,
precipitation, dewatering or separation of the precipitate, drying,
milling, and storage. For example, the temperature of the water may
be within a suitable range for the precipitation of the desired
composition to occur. For example, the temperature of the water may
be raised to an amount suitable for precipitation of the desired
carbonate compound(s) to occur. In such embodiments, the
temperature of the water may be from 5 to 70.degree. C., such as
from 20 to 50.degree. C., and including from 25 to 45.degree. C. As
such, while a given set of precipitation conditions may have a
temperature ranging from 0 to 100.degree. C., the temperature may
be raised in certain embodiments to produce the desired
precipitate. In certain embodiments, the temperature is raised
using energy generated from low or zero carbon dioxide emission
sources, e.g., solar energy source, wind energy source,
hydroelectric energy source, etc.
[0660] The residence time of the precipitate in the precipitator
before the precipitate is removed from the solution, may vary. In
some embodiments, the residence time of the precipitate in the
solution is more than 5 seconds, or between 5 seconds-1 hour, or
between 5 seconds-1 minute, or between 5 seconds to 20 seconds, or
between 5 seconds to 30 seconds, or between 5 seconds to 40
seconds. Without being limited by any theory, it is contemplated
that the residence time of the precipitate may affect the size of
the particle. For example, a shorter residence time may give
smaller size particles or more disperse particles whereas longer
residence time may give agglomerated or larger size particles. In
some embodiments, the residence time in the process of the
invention may be used to make small size as well as large size
particles in a single or multiple batches which may be separated or
may remain mixed for later steps of the process.
[0661] The nature of the precipitate may also be influenced by
selection of appropriate major ion ratios. Major ion ratios may
have influence on polymorph formation, such that the carbonate
products are metastable forms, such as, but not limited to
vaterite, aragonite, amorphous calcium carbonate, or combination
thereof. In some embodiments, the carbonate products may also
include calcite. Such polymorphic precipitates are described in
U.S. application Ser. No. 12/857,248, filed 16 Aug. 2010, which is
incorporated herein by reference in its entirety in the present
disclosure. For example, magnesium may stabilize the vaterite
and/or amorphous calcium carbonate in the precipitate. Rate of
precipitation may also influence compound polymorphic phase
formation and may be controlled in a manner sufficient to produce a
desired precipitate product. The most rapid precipitation can be
achieved by seeding the solution with a desired polymorphic phase.
Without seeding, rapid precipitation can be achieved by rapidly
increasing the pH of the sea water. The higher the pH is, the more
rapid the precipitation may be.
[0662] In some embodiments, a set of conditions to produce the
desired precipitate from the water include, but are not limited to,
the water's temperature and pH, and in some instances the
concentrations of additives and ionic species in the water.
Precipitation conditions may also include factors such as mixing
rate, forms of agitation such as ultrasonics, and the presence of
seed crystals, catalysts, membranes, or substrates. In some
embodiments, precipitation conditions include supersaturated
conditions, temperature, pH, and/or concentration gradients, or
cycling or changing any of these parameters. The protocols employed
to prepare carbonate compound precipitates according to the
invention may be batch or continuous protocols. It will be
appreciated that precipitation conditions may be different to
produce a given precipitate in a continuous flow system compared to
a batch system.
[0663] Following production of the carbonate precipitate from the
water, the resultant precipitated carbonate composition may be
separated from the mother liquor or dewatered to produce the
precipitate product, as illustrated at step 1302 of FIG. 13.
Alternatively, the precipitate is left as is in the mother liquor
or mother supernate and is used as a cementing composition.
Separation of the precipitate can be achieved using any convenient
approach, including a mechanical approach, e.g., where bulk excess
water is drained from the precipitated, e.g., either by gravity
alone or with the addition of vacuum, mechanical pressing, by
filtering the precipitate from the mother liquor to produce a
filtrate, etc. Separation of bulk water produces a wet, dewatered
precipitate. The dewatering station may be any number of dewatering
stations connected to each other to dewater the slurry (e.g.,
parallel, in series, or combination thereof).
[0664] The above protocol results in the production of slurry of
the precipitate and mother liquor. This precipitate in the mother
liquor and/or in the slurry may give the self-cementing
composition. In some embodiments, a portion or whole of the
dewatered precipitate or the slurry is further processed to make
the hydraulic cement or the SCM compositions.
[0665] Where desired, the compositions made up of the precipitate
and the mother liquor may be stored for a period of time following
precipitation and prior to further processing. For example, the
composition may be stored for a period of time ranging from 1 to
1000 days or longer, such as 1 to 10 days or longer, at a
temperature ranging from 1 to 40.degree. C., such as 20 to
25.degree. C.
[0666] The slurry components are then separated. Embodiments may
include treatment of the mother liquor, where the mother liquor may
or may not be present in the same composition as the product. The
resultant mother liquor of the reaction may be disposed of using
any convenient protocol. In certain embodiments, it may be sent to
a tailings pond 1307 for disposal. In certain embodiments, it may
be disposed of in a naturally occurring body of water, e.g., ocean,
sea, lake or river. In certain embodiments, the mother liquor is
returned to the source of feedwater for the methods of invention,
e.g., an ocean or sea. Alternatively, the mother liquor may be
further processed, e.g., subjected to desalination protocols, as
described further in U.S. application Ser. No. 12/163,205, filed
Jun. 27, 2008; the disclosure of which is herein incorporated by
reference in the present disclosure.
[0667] The resultant dewatered precipitate is then dried to produce
the carbonate composition of the invention, as illustrated at step
1304 of FIG. 13. Drying can be achieved by air drying the
precipitate. Where the precipitate is air dried, air drying may be
at a temperature ranging from -70 to 120.degree. C., as desired. In
certain embodiments, drying is achieved by freeze-drying (i.e.,
lyophilization), where the precipitate is frozen, the surrounding
pressure is reduced and enough heat is added to allow the frozen
water in the material to sublime directly from the frozen
precipitate phase to gas. In yet another embodiment, the
precipitate is spray dried to dry the precipitate, where the liquid
containing the precipitate is dried by feeding it through a hot gas
(such as the gaseous waste stream from the power plant), e.g.,
where the liquid feed is pumped through an atomizer into a main
drying chamber and a hot gas is passed as a co-current or
counter-current to the atomizer direction. Depending on the
particular drying protocol of the system, the drying station may
include a filtration element, freeze drying structure, spray drying
structure, etc. The drying step may discharge air and fines
1306.
[0668] In some embodiments, the step of spray drying may include
separation of different sized particles of the precipitate. Where
desired, the dewatered precipitate product from 1302 may be washed
before drying, as illustrated at step 1303 of FIG. 13. The
precipitate may be washed with freshwater, e.g., to remove salts
(such as NaCl) from the dewatered precipitate. Used wash water may
be disposed of as convenient, e.g., by disposing of it in a
tailings pond, etc. The water used for washing may contain metals,
such as, iron, nickel, etc.
[0669] In some embodiments, the dried precipitate is refined,
milled, aged, and/or cured (as shown in the refining step 1305),
e.g., to provide for desired physical characteristics, such as
particle size, surface area, zeta potential, etc., or to add one or
more components to the precipitate, such as admixtures, aggregate,
supplementary cementitious materials, etc., to produce the
carbonate composition. Refinement may include a variety of
different protocols. In certain embodiments, the product is
subjected to mechanical refinement, e.g., grinding, in order to
obtain a product with desired physical properties, e.g., particle
size, etc. The dried precipitate may be milled or ground to obtain
a desired particle size.
[0670] In some embodiments, the calcium carbonate precipitate
formed by the methods and system of the invention, is in a
metastable form including but not limited to, vaterite, aragonite,
amorphous calcium carbonate, or combination thereof. In some
embodiments, the calcium carbonate precipitate formed by the
methods and system of the invention, is in a metastable form
including but not limited to, vaterite, amorphous calcium
carbonate, or combination thereof. The vaterite containing
composition of calcium carbonate, after coming into contact with
water converts to a stable polymorph form such as aragonite,
calcite, or combination thereof with a high compressive
strength.
[0671] The carbonate composition or the cementitous composition,
thus formed, has elements or markers that originate from the carbon
from the source of carbon used in the process. The carbonate
composition after setting, and hardening has a compressive strength
of at least 14 MPa; or at least 16 MPa; or at least 18 MPa; or at
least 20 MPa; or at least 25 MPa; or at least 30 MPa; or at least
35 MPa; or at least 40 MPa; or at least 45 MPa; or at least 50 MPa;
or at least 55 MPa; or at least 60 MPa; or at least 65 MPa; or at
least 70 MPa; or at least 75 MPa; or at least 80 MPa; or at least
85 MPa; or at least 90 MPa; or at least 95 MPa; or at least 100
MPa; or from 14-100 MPa; or from 14-80 MPa; or from 14-75 MPa; or
from 14-70 MPa; or from 14-65 MPa; or from 14-60 MPa; or from 14-55
MPa; or from 14-50 MPa; or from 14-45 MPa; or from 14-40 MPa; or
from 14-35 MPa; or from 14-30 MPa; or from 14-25 MPa; or from 14-20
MPa; or from 14-18 MPa; or from 14-16 MPa; or from 17-35 MPa; or
from 17-30 MPa; or from 17-25 MPa; or from 17-20 MPa; or from 17-18
MPa; or from 20-100 MPa; or from 20-90 MPa; or from 20-80 MPa; or
from 20-75 MPa; or from 20-70 MPa; or from 20-65 MPa; or from 20-60
MPa; or from 20-55 MPa; or from 20-50 MPa; or from 20-45 MPa; or
from 20-40 MPa; or from 20-35 MPa; or from 20-30 MPa; or from 20-25
MPa; or from 30-100 MPa; or from 30-90 MPa; or from 30-80 MPa; or
from 30-75 MPa; or from 30-70 MPa; or from 30-65 MPa; or from 30-60
MPa; or from 30-55 MPa; or from 30-50 MPa; or from 30-45 MPa; or
from 30-40 MPa; or from 30-35 MPa; or from 40-100 MPa; or from
40-90 MPa; or from 40-80 MPa; or from 40-75 MPa; or from 40-70 MPa;
or from 40-65 MPa; or from 40-60 MPa; or from 40-55 MPa; or from
40-50 MPa; or from 40-45 MPa; or from 50-100 MPa; or from 50-90
MPa; or from 50-80 MPa; or from 50-75 MPa; or from 50-70 MPa; or
from 50-65 MPa; or from 50-60 MPa; or from 50-55 MPa; or from
60-100 MPa; or from 60-90 MPa; or from 60-80 MPa; or from 60-75
MPa; or from 60-70 MPa; or from 60-65 MPa; or from 70-100 MPa; or
from 70-90 MPa; or from 70-80 MPa; or from 70-75 MPa; or from
80-100 MPa; or from 80-90 MPa; or from 80-85 MPa; or from 90-100
MPa; or from 90-95 MPa; or 14 MPa; or 16 MPa; or 18 MPa; or 20 MPa;
or 25 MPa; or 30 MPa; or 35 MPa; or 40 MPa; or 45 MPa. For example,
in some embodiments of the foregoing aspects and the foregoing
embodiments, the composition after setting, and hardening has a
compressive strength of 14 MPa to 40 MPa; or 17 MPa to 40 MPa; or
20 MPa to 40 MPa; or 30 MPa to 40 MPa; or 35 MPa to 40 MPa. In some
embodiments, the compressive strengths described herein are the
compressive strengths after 1 day, or 3 days, or 7 days, or 28
days.
[0672] The precipitates, comprising, e.g., calcium and magnesium
carbonates and bicarbonates in some embodiments may be utilized as
building materials, e.g., as cements and aggregates, as described
in commonly assigned U.S. patent application Ser. No. 12/126,776,
filed on 23 May 2008, herein incorporated by reference in its
entirety in the present disclosure.
[0673] The following examples are put forth so as to provide those
of ordinary skill in the art with a complete disclosure and
description of how to make and use the present invention, and are
not intended to limit the scope of what the inventors regard as
their invention nor are they intended to represent that the
experiments below are all or the only experiments performed.
Various modifications of the invention in addition to those
described herein will become apparent to those skilled in the art
from the foregoing description and accompanying figures. Such
modifications fall within the scope of the appended claims. Efforts
have been made to ensure accuracy with respect to numbers used
(e.g. amounts, temperature, etc.) but some experimental errors and
deviations should be accounted for. Unless indicated otherwise,
parts are parts by weight, molecular weight is weight average
molecular weight, temperature is in degrees Centigrade, and
pressure is at or near atmospheric.
[0674] In the examples and elsewhere, abbreviations have the
following meanings:
TABLE-US-00002 AEM = anion exchange membrane Ag = silver Ag/AgCl =
silver/silver chloride cm.sup.2 = centimeter square ClEtOH =
chloroethanol CV = cyclic voltammetry DI = deionized EDC = ethylene
dichloride g = gram HCl = hydrochloric acid hr = hour Hz = hertz M
= molar mA = milliamps mA/cm.sup.2 = milliamps/centimeter square mg
= milligram min. = minute mmol = millimole mol = mole .mu.l =
microliter .mu.m = micrometer mL = milliliter ml/min =
milliliter/minute mV = millivolt mV/s or mVs.sup.-1 =
millivolt/second NaCl = sodium chloride NaOH = sodium hydroxide nm
= nanometer .OMEGA.cm.sup.2 = ohms centimeter square Pd/C =
palladium/carbon Pt = platinum PtIr = platinum iridium rpm =
revolutions per minute STY = space time yield V = voltage w/v =
weight/volume w/w = weight/weight
EXAMPLES
Example 1
[0675] This example illustrates an experimental set up and proposed
experimental conditions for a half cell reaction. The reaction is
carried out in the experimental set up illustrated in FIG. 14.
Cyclic voltammetry is performed on metal-salt anolytes (tin (ii)
chloride, chromium (II) chloride, iron (II) chloride, and copper
(I) chloride).
Example 2
Voltage Savings with CO.sub.2 in the Catholyte
[0676] This example illustrates the highest current density
achieved at 0V in different electrochemical systems. The conditions
used for this experiment were: anode: 6 cm.sup.2 Pt foil; cathode:
6 cm.sup.2 oxygen depolarized cathode; anolyte: 0.5M Cr.sup.2+
solvated with ultrapure deionized water; brine: 15.6 wt % NaCl
solvated with ultrapure deionized water; catholyte: 10 wt % NaOH
solvated with ultrapure deionized water. Solution temperatures were
held constant at 70.degree. C. and re-circulated in the cell at 400
rpm using an LS16 sized peristaltic tubing. The electrochemical
systems used in this experiment were the electrochemical system 500
of FIG. 5A but with 2-compartment system where only one ion
exchange membrane was used (System A in FIG. 15); the
electrochemical system 500 of FIG. 5A with 2-compartment system and
where CO.sub.2 was administered to the catholyte (System B in FIG.
15); the electrochemical system 500 of FIG. 5A with 3-compartment
system (System C in FIG. 15); and the electrochemical system 500 of
FIG. 5A with 3-compartment system and where CO.sub.2 was
administered to the catholyte (System D in FIG. 15).
[0677] The catholyte was bubbled with CO.sub.2 until the pH reached
less than 12 and around 10. As illustrated in FIG. 15, adjusting
the pH of the catholyte via CO.sub.2 injection improved the overall
performance as higher current density was achieved at 0V. Also,
removing a compartment and cation exchange membrane for the
2-compartment improved results over the 3-compartment system. It is
contemplated that there are a reduction of ohmic losses from the
membrane and the electrolyte.
Example 3
Voltage Savings with CO.sub.2 in the Catholyte
[0678] This example illustrates the highest current density
achieved at 0V in different electrochemical systems. The conditions
used for this experiment were: anode: 6 cm.sup.2 Pt foil; cathode:
6 cm.sup.2 Pt foil; anolyte: 0.5M Cr.sup.2+ solvated with ultrapure
deionized water; brine: 15.6 wt % NaCl solvated with ultrapure
deionized water; catholyte: 10 wt % NaOH solvated with ultrapure
deionized water. Solution temperatures were held constant at
70.degree. C. and re-circulated in the cell at 400 rpm using an
LS16 sized peristaltic tubing.
[0679] The electrochemical systems used in this experiment were the
electrochemical system 400 of FIG. 4A but with 2-compartment system
where only one ion exchange membrane was used (System E in FIG.
16); and the electrochemical system 400 of FIG. 4A with
2-compartment system and where CO.sub.2 was administered to the
catholyte (System F in FIG. 16). It is to be understood that a
similar experiment can be set-up for 3-compartment system, as
described in Example 2.
[0680] The catholyte was bubbled with CO.sub.2 until the pH reached
less than 12 and around 10. As illustrated in FIG. 16, adjusting
the pH of the catholyte via CO.sub.2 injection improved the overall
performance as it improved the voltage by 300 mV at 150
mA/cm.sup.2. Here the cathode reaction produced hydrogen that can
be used for metal ion regeneration through the use of hydrogenation
(as illustrated in FIG. 6). For this test, the current was
increased galvanostatically and the resulting cell voltage was
recorded.
Example 4
Treatment of Metal with Hydrogen Gas
Experiment 1: Hydrogenation of Chromium
[0681] This example illustrates the hydrogenation of the chromium
ion in the higher oxidation state to form the chromium ion in the
lower oxidation state and hydrochloric acid. FIG. 17A is an
illustration of electrochemical cyclic voltammograms to detect the
presence of Cr.sup.2+ after reducing a 0.46M solution of Cr.sup.3+
with hydrogen at 25.degree. C. for 8 hrs. Two standard solutions of
0.46M Cr.sup.2+ and 0.46M Cr.sup.3+ were prepared and characterized
electrochemically. The conditions used for this experiment were:
anode: 6 cm.sup.2 Pt foil; cathode: 6 cm.sup.2 Pt foil; anolyte:
0.46M Cr.sup.2+, 0.46M Cr.sup.3+, and reduced solution containing
Cr.sup.3+ and Cr.sup.2+ solvated with ultrapure deionized water.
Solution temperatures were held constant at 70.degree.. The voltage
was scanned from 0 to 0.8V vs. Ag/AgCl reference electrode at 10
mV/s. It was expected to see Cr.sup.2+ oxidation with no oxidation
signals for the Cr.sup.3+ standard in this voltage range. Since an
oxidation peak for Cr.sup.2+ standard was seen, the solution that
had been reduced from Cr.sup.3+ to Cr.sup.2+ was tested using
cyclic voltammetry. As illustrated in FIG. 17A, the reduced sample
showed the presence of Cr.sup.2+ indicating a reduction of
Cr.sup.3+ to Cr.sup.2+ via hydrogenation.
Experiment 2: Hydrogenation of Copper
[0682] This example illustrates the hydrogenation of the copper ion
in the higher oxidation state to form the copper ion in the lower
oxidation state and hydrochloric acid. To a 1-necked 100 ml round
bottom flask, was added 100 ml of DI water. Using a t-necked gas
inlet adapter, the water was aspirated and filled 5.times. with
nitrogen. To this oxygen free water was then added 1.7 g (0.01 mol)
of CuCl.sub.2.2H.sub.2O (0.1M in CuCl.sub.2.2H.sub.2O) and magnetic
stir bar. To the resulting light blue liquid, was added 300 mg of
1% Pd/C and the mix was rapidly stirred under nitrogen. The mixture
was then aspirated 4.times. with H.sub.2 gas from a rubber bladder
and finally kept under positive H.sub.2 pressure stirring rapidly.
After 12 h the stirrer was stopped and a .about.2 mL aliquot was
removed and filtered through a 0.2 .mu.m filter disk using a 5 ml
syringe. The resulting filtrate was clear. As illustrated in FIG.
17B, the UV-VIS showed .about.94% conversion of Cu(II) to Cu(I)
(top curve is for Cu(II) before reaction and bottom curve is for
Cu(II) after reaction) with a notably acidic solution (showing the
formation of HCl).
Example 5
Formation of Halohydrocarbon from Unsaturated Hydrocarbon
[0683] Formation of EDC from Ethylene Using Copper Chloride
Experiment 1
[0684] This experiment is directed to the formation of ethylene
dichloride (EDC) from ethylene using cupric chloride. The
experiment was conducted in a pressure vessel. The pressure vessel
contained an outer jacket containing the catalyst, i.e. cupric
chloride solution and an inlet for bubbling ethylene gas in the
cupric chloride solution. The catalyst solution used in the
experiment was 200 mL of 1M NaCl, 1M CuCl.sub.2, and 0.5 mL of
12.1M HCl. This solution was clear and green. The pressure vessel
was heated to 160.degree. C. and ethylene gas was passed into the
vessel for up to 300 psi for 30 minutes. The solution after
reaction was found to be much darker than the starting solution.
The product formed in the solution was extracted with 50 mL pentane
and was then separated using a separatory funnel. The pentane
extract containing the EDC was subjected to gas-chromatography
(GC). FIG. 18 illustrates a peak at the retention time for EDC. The
other small peaks pertain to pentane. FIG. 19 shows that the CV of
a pre-reaction catalyst solution was flat and the CV of a
post-reaction solution showed oxidation at 0.4V (for the half cell
and the reference electrode). The UV-Vis of the product gave a
Cu.sup.2+ concentration of 0.973M.
Experiment 2
[0685] This experiment is directed to the formation of ethylene
dichloride (EDC) from ethylene using cupric chloride. The
experiment was conducted in a pressure vessel. The pressure vessel
contained an outer jacket containing the catalyst, i.e. cupric
chloride solution and an inlet for bubbling ethylene gas in the
cupric chloride solution. The concentration of the reactants was,
as shown in Table II below. The pressure vessel was heated to
160.degree. C. and ethylene gas was passed into the vessel
containing 200 mL of the solution at 300 psi for between 30 min.-1
hr in the experiments. The vessel was cooled to 4.degree. C. before
venting and opening. The product formed in the solution was
extracted with ethyl acetate and was then separated using a
separatory funnel. The ethyl acetate extract containing the EDC was
subjected to gas-chromatography (GC).
TABLE-US-00003 TABLE II Mass Selectivity: Chloro- Cu EDC/(EDC +
Time HCl EDC ethanol Utilization ClEtOH) (hrs) CuCl.sub.2 CuCl NaCl
(M) (mg) (mg) (EDC) STY % 0.5 6 0.5 1 0.03 3,909.26 395.13 8.77%
0.526 90.82% 0.5 4.5 0.5 2.5 0.03 3,686.00 325.50 11.03% 0.496
91.89%
Formation of Dichloropropane from Propylene Using Copper
Chloride
[0686] This experiment is directed to the formation of
1,2-dichloropropane (DCP) from propylene using cupric chloride. The
experiment was conducted in a pressure vessel. The pressure vessel
contained an outer jacket containing the catalyst, i.e. cupric
chloride solution and an inlet for bubbling propylene gas in the
cupric chloride solution. A 150 mL solution of 5M CuCl.sub.2, 0.5M
CuCl, 1M NaCl, and 0.03M HCl was placed into a glass-lined 450 mL
stirred pressure vessel. After purging the closed container with
N.sub.2, it was heated to 160.degree. C. After reaching this
temperature, propylene was added to the container to raise the
pressure from the autogenous pressure, mostly owing from water
vapor, to a pressure of 130 psig. After 15 minutes, more propylene
was added to raise the pressure from 120 psig to 140 psig. After an
additional 15 minutes, the pressure was 135 psig. At this time, the
reactor was cooled to 14.degree. C., depressurized, and opened.
Ethyl acetate was used to rinse the reactor parts and then was used
as the extraction solvent. The product was analyzed by gas
chromatography which showed 0.203 g of 1,2-dichloropropane that was
recovered in the ethyl acetate phase.
Example 6
Use of Ligand
[0687] In regards to studying a ligated copper system, a sample was
made using the ligand N,N,N,N-tetramethylethylenediamine
(TMEDA).
##STR00022##
[0688] Various other examples for the ligand are illustrated in
FIG. 20 which have been described herein. Any of the ligands
illustrated in FIG. 20 can be used in the catalytic reactions of
the invention. Other examples of the ligands are also illustrated
in Example 10. The aqueous solution consisted of the following:
2.5M NaCl, 1.0M CuCl.sub.2, 0.5M CuCl, and 2.2M TMEDA. Upon mixing
the ligand with the rest of the solution, a brownish solution
changed quickly to a dark blue solution indicating ligation had
occurred. The treatment of the above solution (diluted) with
dichloromethane followed by vigorous shaking showed that after
phase separation, the complex was not pulled into the extraction
solvent. This effect is desirable since this can reduce metal
complex contamination when an extraction method is used for
isolation of organic products from the metal ions. The pH of the
solution changed from acidic to mildly basic (pH 2.6 to 7.8) upon
addition of the ligand. This effect of the ligand on the pH can be
a benefit to reducing the corrosive nature of the copper chloride
catalyst system.
Example 7
Voltage Savings with the Ligand
[0689] A half cell reaction was carried out using the metal-ligand
solution of Example 6 and the set up of Example 1. The working
electrode for the half cell reaction was 4 cm.sup.2 Pt Gauze 52
mesh anode; the counter electrode was 6 cm.sup.2 Pt foil; and the
reference electrode was Saturated Calomel electrode (SCE). The
solution in the beaker was kept at 70.degree. C. In one experiment,
a solution contained 2.5M NaCl, 1.0M CuCl.sub.2, and 0.5M CuCl and
no ligand. In the other experiment, the solution contained 2.5M
NaCl, 1.0M CuCl.sub.2, 0.5M CuCl, and 2.2M TMEDA (Example 6). As
illustrated in FIG. 21, a voltage savings of about 200 mV was
observed at 150 mA/cm.sup.2 when the ligand was used in the metal
solution.
Example 8
Voltage Savings with the Ligand
[0690] A full cell reaction was carried out using the metal-ligand
solution of Example 6 and the cell of FIG. 4A. The components of
the cell were commercially available and included Pt guaze anode;
fine Ni mesh cathode; anion exchange membrane as AHA; and the
cation exchange membrane as 2100. The catholyte was 10 wt % NaOH.
In 1st experiment, the anolyte was 2.5M NaCl, 1.0M CuCl.sub.2, and
0.5M CuCl and no ligand and in the 2nd experiment, the anolyte was
2.5M NaCl, 1.0M CuCl.sub.2, 0.5M CuCl, and 2.2M TMEDA (Example 6).
FIG. 22 illustrates that the presence of the ligand reduced the
redox potential (about 300 mV in this experiment) which resulted in
the decrease in the cell voltage. The color of the ligand solution
also changed dramatically which could be due to oxidation of
Cu.sup.+ to Cu.sup.2+.
Example 9
Anion Exchange Membrane
[0691] This example illustrates effect of selection of AEM on the
prevention of the crossover of the metal ions through the AEM to
the middle chamber. This example also illustrates the selection of
AEM that prevents crossover of metal ions, fouling of the membrane,
and increase in resistance.
Direct Current Method
[0692] A series of anion exchange membranes were tested in this
experiment including ACS, ACM and AHA from Astom Corporation, FAB
and FAP from FuMaTech, and DSV from Asahi Glass. The AEM was
sandwiched in between an anolyte containing 3M CuCl.sub.2/1M
CuCl/4.6M NaCl and a chamber containing 4.6M NaCl electrolyte. A
standard three-electrode setup was used including a platinum gauze
working/counter electrode and saturated calomel electrode (SCE)
reference. An additional two SCE's were placed in a luggin
capillary on either side of the membrane. Small current steps of 1,
2, 4, 5, 7.5, 10, and 11 mA/cm.sup.2 were applied and a multimeter
was used to monitor the change in potential between the two SCEs.
The slope of the current density vs voltage change equals the
through plane area resistance. The results are illustrated in FIG.
23. The resistance values in FIG. 23 include the AEM and solution
resistance. ACS, ACM, and FAB showed the highest resistance. It is
contemplated that these AEMs have been designed for enhanced proton
blocking and require a highly acidic medium for proper function.
FAP, DSV, and AHA had a reduction of over 5 .OMEGA.cm.sup.2. FAP
and DSV showed significant signs of permeation of Cu-base species.
AHA was found to be most effective against crossover and was found
to have least resistance.
Impedance Spectroscopy Method
[0693] In this experiment, a two Pt-foil electrode setup was used.
The AHA membrane was sandwiched in between a saturated brine
solution and the Cu-base electrolyte. The frequency range was
between 15,000 Hz-0.001 Hz at an amplitude of 20 mA and a DC signal
of 150 mA/cm.sup.2. The cell was run with and without the AHA and
the difference in high frequency x-intercepts represented the AEM
area resistance.
[0694] The AHA resistance in three different Cu-base electrolytes
is summarized in Table III. Solution A is: 4.6M NaCl: solution B
is: 0.5M CuCl/2.5M NaCl; solution C is: 4.5M CuCl.sub.2/0.5M
CuCl/2.5M NaCl; and solution D is: 4.5M CuCl.sub.2/0.5M CuCl.
TABLE-US-00004 TABLE III Summary of results for resistance
measurements of AHA in different Cu-base solutions .OMEGA.cm.sup.2
.OMEGA.cm.sup.2 AHA + V loss @ Chemistry solution solution
.OMEGA.cm.sup.2 AHA 150 mA/cm.sup.2 A-membrane-A 1.28 3.14 1.86
0.28 A-membrane-B 1.28/1.77 3.58 1.81-2.06 0.272-0.308 A-membrane-C
1.28/2.8 4.96 2.16-2.92 0.324-0.438 A-membrane-D 1.28/3.14 7.51
4.37-5.3 0.656-0.795
[0695] It was observed that solution B with no CuCl.sub.2 had a
resistance similar to plain NaCl with no added CuClx. Solution C
showed a voltage loss between 320-430 mV. Adding CuCl.sub.2 into
the anolyte produced a small increase in resistance. It is
contemplated that this could be due to the change in solution
resistance through the AEM. Solution D, which is equivalent to
solution C with no NaCl, showed over a 2-fold increase in voltage
loss. It is contemplated that there may be a change in copper
speciation leading to an increase in resistance.
Permeability or Crossover of Cu-Chloride Complexes
[0696] A full cell configuration was used to measure the Cu-species
transport through the AEM. A solution of 4.5M CuCl.sub.2/0.5M
CuCl/2.5M NaCl was fed into the anolyte, 4.6M NaCl was fed into the
intermediate compartment, and 10 wt % NaOH was fed into the
catholyte at 70.degree. C. The cell was operated at 150 mA/cm.sup.2
and 300 mA/cm.sup.2 at a series of flow rates. For each flow rate
(such as 20 ml/min, 40 ml/min, etc.) the copper ion concentration
was measured pre testing and after running the cell for 30 min.
UV-VIS was used to measure the total Cu in the brine solution in
the intermediate compartment, pre and post testing. This value was
then compared to the number of faradaic moles passed to obtain a
percent rejection. The results are summarized in FIG. 24. As
illustrated in FIG. 24, the AHA membrane provided >99%+/-0.01%
rejection of all Cu-species in all cases.
Example 10
Use of a Ligand
[0697] To a 4 mL screw cap glass vial, containing a stir bar, was
added 49 mg of CuCl (0.5 mmol). To this solution, the ligand
together with 100 .mu.l water was added and the reaction mixture
was allowed to react for 2-3 hours at room temperature. Next a 2 mL
aqueous stock solution of 6M CuCl.sub.2 and 1M NaCl, which was
heated for complete dissolution, was added. The vial was capped
with a pre-slit septa made out of TEF and silicone. The vial was
placed in a clam shell pressure reactor on top of a stirring hot
plate. The atmosphere inside the reactor was exchanged to N.sub.2.
The stirring was started at 620 rpm and the reactor was heated to
140.degree. C. After reaching temperature, the reactor with
multiple vials inside was pressurized to 350 psi total pressure.
After 1 hour, the reactor was cooled to below 30.degree. C. and
slowly vented. The reaction mixture was extracted with 1 mL of
ethyl acetate. The organic phase was analyzed by GC (gas
chromatography) for ethylene dichloride and chloroethanol (ClEtOH)
content. FIG. 25A and Table IV illustrate the specific ligand, the
amount of the ligand, the reaction conditions, and the amount of
main products formed. A comparative example without ligand is
included as well. FIG. 25B illustrates other examples of the
ligands that can be used in the catalytic reaction. Table IV
demonstrates that the ligand not only improves the yield of EDC in
the reaction but also improves the selectivity.
TABLE-US-00005 TABLE IV Ligand amount in EDC by GC in ClEtOH by GC
Ligand # mmol mg/ml in mg/ml Selectivity no ligand N/A 10.20 1.53
0.87 2 0.5 6.89 1.33 0.84 2 2 3.87 1.15 0.77 3 0.5 8.20 1.48 0.85 3
2 11.56 1.73 0.87 4 0.5 7.84 1.38 0.85 4 2 1.75 0.46 0.79 5 0.5
7.75 1.36 0.85 5 2 2.11 0.70 0.75 6 0.5 15.49 1.78 0.90 6 2 16.29
1.98 0.89 7 0.5 13.42 1.44 0.90 8 0.5 6.88 0.97 0.88 10 0.5 10.14
1.66 0.86 10 2 15.96 1.59 0.91 11 0.5 11.10 1.93 0.85 11 2 12.22
2.01 0.86 12 0.5 9.75 1.50 0.87 12 2 1.06 0.45 0.70
Example 11
Oxidation of Iron Metal in Electrochemical Cell
[0698] A half cell reaction was carried out using the iron solution
with a setup shown in Example 1. The working electrode for the half
cell reaction was 6 cm.sup.2 PtIr 152-mesh gauze; the counter
electrode was 8 cm.sup.2 Pt foil; and the reference electrode was
standard hydrogen electrode (SHE) Ag/AgCl. The solution in the
beaker was kept at 70.degree. C. In the experiment, a solution
contained 1M FeCl.sub.2 and 2.5M NaCl. As illustrated in FIG. 26,
oxidation of Fe.sup.2+ to Fe.sup.3+ at the anode was observed at
voltage scan rate of 5 mV/s.
Example 12
Electrolytes in Electrochemical Cell
[0699] A full cell reaction was carried out using sodium chloride
and ammonium chloride as electrolytes. The components of the cell
were commercially available and included Pt guaze anode; PGM mesh
cathode; anion exchange membrane as AHA from Neosepta; and the
cation exchange membrane as Dupont N2100. The catholyte was 10 wt %
NaOH. In 1st experiment, the anolyte was 4.5M CuCl.sub.2/0.5M
CuCl/2.5M NaCl and in the 2nd experiment, the anolyte was 4.5M
CuCl.sub.2/0.5M CuCl/2.5M NH.sub.4Cl. The solution in the cell was
kept at 70.degree. C. FIG. 27 illustrates that although both sodium
chloride and ammonium chloride electrolytes work well in the
electrochemical cell, the NH.sub.4Cl anolyte lowered the operating
cell voltage by 200-250 mV at 300 mA/cm.sup.2. It is contemplated
that it may be due to the increased conductivity of the anolyte
which resulted in a lower resistance across the AEM.
Example 13
AEM Conditioning at the Start-Up of the Electrochemical Cell
[0700] This experiment was related to the conditioning of the AEM
before the start of the electrochemical cell. Initial solutions
introduced into the full cell were 0.5M Na.sub.2SO.sub.4 as the
anolyte, 4.6M NaCl into the intermediate compartment, and 10 wt %
NaOH as the catholyte. The membranes were FAS from FuMaTech as the
anion exchange membrane and N2100 from Dupont as the cation
exchange membrane. The cell was then run at 300 mA/cm.sup.2. At
this point, the anodic reaction was oxygen evolution and the
cathodic reaction was water reduction. As illustrated in FIG. 28,
the initial overall cell voltage of about 4.5V was seen. Once the
voltage was stabilized, a valve was switched and the
Na.sub.2SO.sub.4 was flushed out of the cell and the anolyte (4.5M
CuCl.sub.2/0.5M CuCl/2.5M NaCl) was then fed into the anode
chamber. The cell was constantly held at 300 mA/cm.sup.2 during
this time. The anodic reaction now was copper oxidation, as
illustrated in FIG. 28 as the sudden drop in cell voltage. The
black curve shows the voltage when the copper electrolyte was
introduced into the cell (with no initial voltage stabilization by
sodium sulfate) before a voltage was applied. There was about a 200
mV voltage savings when Na.sub.2SO.sub.4 was used at the start-up
and the voltage was significantly more stable for the duration of
the test. The conditioning of the AEM at the operating current
density prior to introducing the copper-base electrolyte may be
beneficial for voltage and stability.
Example 14
Re-Circulation of Aqueous Phase from Catalytic Reactor to
Electrochemical System
[0701] This example illustrates the re-circulation of the Cu(I)
solution generated by a catalysis reactor to the electrochemical
cell containing a PtIr gauze electrode. A solution containing 4.5M
Cu(II), 0.1M Cu(I), and 1.0M NaCl was charged to the Parr bomb
reactor for a 60 min. reaction at 160.degree. C. and 330 psi. The
same solution was tested via anodic cyclic voltammetry (CV) before
and after the catalysis run to look for effects of organic residues
such as EDC or residual extractant on anode performance. Each CV
experiment was conducted at 70.degree. C. with 10 mVs.sup.-1 scan
rate for five cycles, 0.3 to 0.8V vs. saturated calomel electrode
(SCE).
[0702] FIG. 29 illustrates the resulting V/I response of a PtIr
gauze electrode (6 cm.sup.2) in solutions before and after
catalysis (labeled pre and post, respectively). As illustrated in
FIG. 29, redox potential (voltage at zero current) shifted to lower
voltages post-catalysis as expected from the Nernst equation for an
increase in Cu(I) concentration. The increase in the Cu(I)
concentration was due to EDC production with Cu(I) regeneration
during a catalysis reaction. The pre-catalysis CV curve reached a
limiting current near 0.5 A due to mass transfer limitations at low
Cu(I) concentration. The Cu(I) generation during the catalysis run
was signified by a marked improvement in kinetic behavior
post-catalysis, illustrated in FIG. 29 as a steeper and linear UV
slope with no limiting current reached. No negative effects of
residual EDC or other organics were apparent as indicated by the
typical reversible UV curve obtained in the post-catalysis CV.
Example 15
Re-Circulation of Aqueous Phase from Catalytic Reactor Containing
Ligand
[0703] This example illustrates the re-circulation of the Cu(I)
solution containing the ligand from the catalysis reactor to the
electrochemical cell. A 2 mL sample of the catalyst solution tested
in the catalysis high throughput reactor was sent to a
three-electrode micro-cell for electrochemical screening via anodic
cyclic voltammetry (CV) to determine if a correlation existed
between redox potential and catalysis performance. The ligands
were:
##STR00023##
[0704] The catalyst solution contained 5.0M Cu(II)/0.5M Cu(I)/0.5M
or 1M ligand/1M NaCl. These ligand solutions were tested in the
anodic micro-half-cell via cyclic voltammetry to measure redox
potential. The micro-cell consisted of a PtIr foil working
electrode, Pt foil counter electrode, and a capillary bridge to a
Ag/AgCl microelectrode as reference. All electrodes were sealed
into a 4 mL vial, heated to 70.degree. C. and stirred at 100 rpm.
Each CV experiment was conducted at 70.degree. C. with 10 mV
s.sup.-1 scan rate for five cycles, 0.3 to 0.8 V vs. Ag/AgCl
reference electrode.
[0705] Table V below shows the voltages obtained for five catalytic
re-circulated solutions. The results indicated that ligand enhanced
the EDC production and the re-circulated catalytic solution
containing the ligand to the electrochemical cell, reduced the
electrochemical voltage. Table V shows that the redox potential of
samples containing ligand #1 (samples A and B) had a reduced redox
potential compared to the equivalent ligand free system E. Samples
C and D that contained the ligand #2 had a similar redox potential
compared to the ligand free sample E.
TABLE-US-00006 TABLE V Sample Ligand # Concentration CV A 1 0.5
0.684 B 1 1 0.676 C 2 1 0.739 D 2 0.5 0.737 E No ligand N/A
0.728
Example 16
Formation of PCH, DCP, Isopropanol and Isopropyl Chloride from
Propylene Using Copper Chloride
Experiment 1
[0706] A solution of CuCl.sub.2 (1.0 mol/kg), CuCl (0.19 mol/kg),
NaCl (0.66 mol/kg), and HCl (0.0091 mol/kg) was heated in a Parr
reactor under propylene pressure to 130.degree. C. for 15 minutes.
The reactor was depressurized into a bubbler trap at 0.degree. C.
to capture volatile compounds. When the reactor was opened, the
solution was extracted three times with an organic solvent, e.g.
ethyl acetate or dichloromethane, which was analyzed with a gas
chromatograph equipped with a mass spectrometer. A total of 11.4
umol DCP and 12.0 umol PCH were measured. The amounts of recyclable
products measured were 622 umol isopropanol, 47.9 umol acetone, and
73.0 umol isopropyl chloride.
Experiment 2
[0707] A solution of CuCl.sub.2 (0.71 mol/kg), CuCl (0.71 mol/kg),
and NaCl (2.76 mol/kg) was heated in a Parr reactor under propylene
pressure to 150.degree. C. for 15 minutes. The reactor was
depressurized into a bubbler trap at 0.degree. C. to capture
volatile compounds. When the reactor was opened, the solution was
extracted three times with an organic solvent, e.g. ethyl acetate
or dichloromethane, which was analyzed with a gas chromatograph
equipped with a mass spectrometer. A total of 15.6 umol DCP and
62.4 umol PCH were measured. The amounts of recyclable products
measured were 1087 umol isopropanol, 18.8 umol acetone, and 80.1
umol isopropyl chloride.
Example 17
Formation of PCH from Propylene Using Palladium Chloride and Copper
Chloride
[0708] A solution of CuCl.sub.2 (2.80 mol/kg), CuCl (0.54 mol/kg),
NaCl (1.84 mol/kg), and PdCl.sub.2 (0.012 mol/kg) were heated in a
Parr reactor under propylene pressure to 130.degree. C. for 15
minutes. The reactor was depressurized into a bubbler trap at
0.degree. C. to capture volatile compounds. When the reactor was
opened, the solution was extracted three times with an organic
solvent, e.g. ethyl acetate or dichloromethane, which was analyzed
with a gas chromatograph equipped with a mass spectrometer. A total
of 0.29 mmol DCP and 1.24 mmol PCH were measured. The amounts of
recyclable products measured were 9.23 mmol isopropanol, 3.17 mmol
acetone, and 10.9 mmol isopropyl chloride.
Example 18
Recycling of Isopropanol
[0709] A solution of CuCl.sub.2 (3.0 mol/kg), CuCl (0.50 mol/kg),
and NaCl (2.0 mol/kg) were heated with added isopropanol in a Parr
reactor at 140.degree. C. for 15 minutes. The reactor was
constantly purged with a flow of N.sub.2 into a bubbler trap at
0.degree. C. to capture volatile compounds. When the reactor was
opened, the solution was extracted three times with an organic
solvent, e.g. ethyl acetate or dichloromethane, which was analyzed
with a gas chromatograph equipped with a mass spectrometer.
Propylene, isopropanol, isopropyl chloride, PCH, and DCP were all
detected, indicating that isopropanol can be recycled and converted
into desired products.
Example 19
Recycling of Isopropyl Chloride
[0710] Similar to Example 18, reaction was conducted with isopropyl
chloride instead of isopropanol. The same products were
observed.
Example 20
Conversion of DCP to PCH
[0711] In order to measure conversion of DCP to PCH, seven aqueous
salt solutions were tested. The salt solutions comprised
CuCl.sub.2, CuCl, and NaCl. The salts were weighed into 10 ml vials
with water added to bring the solution volume to approximately 4
ml. 50 .mu.L of DCP was added to each vial and then a stir bar was
also added. The vials were closed with a split-septa cap and placed
inside an 8 well high throughput reactor. The entire system was
heated to 150.degree. C. for 30 minutes, during which time the
vials were all stirred at 600 rpm. The organics were extracted
using 4 ml of ethyl acetate and the resulting solutions were
measured by GC-MS. Using the peak areas from the GC-MS, the
following conversions were obtained shown in Table VI:
TABLE-US-00007 TABLE VI Experiment 1 2 3 4 5 6 7 CuCl.sub.2 3.0 3.0
1.5 3.0 3.0 0.0 0.0 (mol/kg) CuCl 1.0 1.0 0.5 0.0 0.0 1.0 1.0
(mol/kg) NaCl 2.0 0.0 1.0 2.0 0.0 2.0 0.0 (mol/kg) Estimated 7.0%
12.7% 10.1% 7.2% 10.7% 14.7% 13.6% Conversion To PCH
[0712] It may be noted that some DCP partitions into the vapor
space in the vials, therefore, these numbers represent a lower
bound on the conversion to PCH. It was observed that lower
CuCl.sub.2 concentrations lead to higher conversion to PCH.
Example 21
Improved Selectivity for PCH Over DCP
Experiment 1
[0713] An aqueous solution of CuCl.sub.2 (2.0 mol/kg) and CuCl (1.0
mol/kg) was heated in a Parr reactor under propylene pressure to
140.degree. C. for 30 minutes. The reactor was depressurized into a
bubbler trap at 0.degree. C. to capture volatile compounds. When
the reactor was opened, the solution was extracted three times with
an organic solvent, e.g. ethyl acetate or dichloromethane, which
was analyzed with a gas chromatograph equipped with a mass
spectrometer. A total of 47 umol DCP and 229 umol PCH were
measured. The amounts of recyclable products measured were 5834
umol isopropanol, 23 umol acetone, and 189 umol isopropyl
chloride.
Experiment 2
[0714] An aqueous solution of CuCl.sub.2 (1.0 mol/kg), CuCl (1.0
mol/kg), and NaCl (1.0 mol/kg) was heated in a Parr reactor under
propylene pressure to 140.degree. C. for 30 minutes. The reactor
was depressurized into a bubbler trap at 0.degree. C. to capture
volatile compounds. When the reactor was opened, the solution was
extracted three times with an organic solvent, e.g. ethyl acetate
or dichloromethane, which was analyzed with a gas chromatograph
equipped with a mass spectrometer. A total of 15 umol DCP and 88
umol PCH were measured. The amounts of recyclable products measured
were 917 umol isopropanol, 4 umol acetone, and 35 umol isopropyl
chloride.
Example 22
Lowering of Water in PO Process
[0715] A 40 wt % solution of propylene chlorohydrin is combined
with a 10 wt % solution of sodium hydroxide and brine. The use of
the more concentrated PCH reduces the brine effluent from 46.2 to
10.1 tonnes per tonne of propylene oxide resulting in significant
cost savings for the handling of this stream. In another example,
feeding a solution of PCH in DCP may lower the total water
discharged to around 7 tonnes per tonne PO, which is due to the
amount of water contained in the added NaOH solution.
Example 23
Formation of PO from PCH
[0716] A glass vial was loaded with 5 mL of 0.1 N NaOH and 100 ul
of PCH (70% 1-chloro-2-propanol and 30% 2-chloro-1-propanol). The
vial was stirred with a magnetic stir bar for 20 hours. Afterward,
a 1 ml aliquot was extracted with 2 ml of ethyl acetate that was
subsequently analyzed by gas chromatography with a mass
spectrometer detector. Propylene oxide as well as both isomers of
PCH was observed, as determined by their fragmentation
patterns.
Example 24
Formation of PO from PCH in Presence of DCP
[0717] A 500 ml round bottom flask was charged with 99.90 g DCP,
0.933 g octane as an internal standard, and 4.764 g (50.4 mmol)
PCH. The flask was equipped with a condenser on top of which was a
barbed fitting with a tube that ran into a vial of ethyl acetate in
ice water bath. Any gas generated and distilled through the
condenser was collected in the ethyl acetate trap. The solution was
brought to a boil at roughly 90.degree. C. At specific time
intervals, 4 charges each of 10 ml of 1 N NaOH (10 mmol) was added
through the top of the condenser and allowed to trickle down into
the hot solution. At the end of the reaction, 34.5 mmol propylene
oxide and 3.0 mmol propylene glycol were measured as products, and
7.9 mmol PCH was measured as un-reacted. This correlates to 92%
propylene oxide with 90% mass balance closure.
Example 25
Formation of PO from PCH in Presence of DCP
[0718] A glass vial was charged with 1900 ul DCP and 100 ul (1.2
mmol) PCH and held at room temperature. To this, 300 ul 1 N NaOH
(0.3 mmol) was added and the vial was mixed vigorously. Samples
from before and after the reaction showed a reduction of the PCH
amount by 31% with a concomitant increase in propylene oxide.
* * * * *