U.S. patent application number 16/084613 was filed with the patent office on 2019-03-07 for methods and compositions for prevention of fouling in caustic towers.
The applicant listed for this patent is General Electric Company. Invention is credited to Mike HONG, Yongtao SHI, Xiaofeng TANG, Chun XU, Dengchao YAN, Guixi ZHANG.
Application Number | 20190071610 16/084613 |
Document ID | / |
Family ID | 59850243 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190071610 |
Kind Code |
A1 |
TANG; Xiaofeng ; et
al. |
March 7, 2019 |
METHODS AND COMPOSITIONS FOR PREVENTION OF FOULING IN CAUSTIC
TOWERS
Abstract
Provided are methods and compositions for inhibiting carbonyl
based fouling materials of basic wash systems. Said methods
comprise contacting the hydrocarbon stream that is or will be
subjected to said wash systems with water soluble or water
dispersible copolymers. Said copolymers comprise repeat units of
ethylenically unsaturated monomers such as acrylic acid with other
repeat units such as alkyl acrylates, allyl ethers, ethoxylated
allyl repeat units, etc. In other embodiments, a third repeat unit
is present and may comprise a hydrophobic moiety such as a styrene
repeat unit.
Inventors: |
TANG; Xiaofeng; (Shanghai,
CN) ; ZHANG; Guixi; (Shanghai, CN) ; HONG;
Mike; (Shanghai, CN) ; SHI; Yongtao;
(Shanghai, CN) ; XU; Chun; (Shanghai, CN) ;
YAN; Dengchao; (Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Family ID: |
59850243 |
Appl. No.: |
16/084613 |
Filed: |
March 18, 2016 |
PCT Filed: |
March 18, 2016 |
PCT NO: |
PCT/CN2016/076767 |
371 Date: |
September 13, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 19/02 20130101;
C10G 2300/202 20130101; C09K 15/28 20130101; C08F 220/382 20200201;
C10G 75/04 20130101; C08F 228/02 20130101; C10G 19/04 20130101;
C08F 220/06 20130101; C08F 220/58 20130101; C09K 15/12 20130101;
C08F 220/38 20130101; C08F 220/585 20200201; C08F 220/06 20130101;
C08F 220/585 20200201; C08F 220/06 20130101; C08F 220/585
20200201 |
International
Class: |
C10G 75/04 20060101
C10G075/04; C09K 15/12 20060101 C09K015/12; C09K 15/28 20060101
C09K015/28; C08F 220/06 20060101 C08F220/06; C08F 220/58 20060101
C08F220/58; C08F 220/38 20060101 C08F220/38; C10G 19/02 20060101
C10G019/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2016 |
CN |
PCT/CN2016/076767 |
Claims
1. A method for inhibiting the formation of fouling materials
comprising contacting a hydrocarbon stream containing carbonyl
compounds with an antifoulant and treating said hydrocarbon stream
with a basic wash, wherein said antifoulant comprises a polymer
having repeat units characterized by the formula ##STR00015##
wherein a must be present, b or c or b+c is present and d may or
may not be present; E is a repeat unit remaining after
polymerization of an ethylenically unsaturated compound; each
R.sub.1 is independently chosen from H or lower (C.sub.1-C.sub.4)
alkyl; R.sub.2 is a hydroxy substituted alkyl or alkylene moiety
having from about 1-6 carbon atoms, X is an anionic radical
selected from the group consisting of SO.sub.3, OSO.sub.3,
PO.sub.3OPO.sub.3 or COO; M is H or hydrogens or any water soluble
cationic moiety that counterbalances the valence of the anionic
radical X; F is an ethylenically unsaturated hydrophobic moiety; Q
in repeat unit c is chosen from C.sub.1-C.sub.3 alkylene or
carbonyl, m is 0 or 1, R.sub.3 is CH.sub.2--CH--O .sub.n or
CH.sub.2--CH--CH.sub.3--O .sub.n wherein n is from 1 to about 100
or R.sub.3 is CH.sub.2--CHOH or CH.sub.2--CH--(OH)--CH.sub.2;
R.sub.4 is H, OH, SO.sub.3M, OSO.sub.3M, PO.sub.3M, OPO.sub.3M, or
CO.sub.2M; with the proviso that when d is present it is present in
an amount of 0.01-0.8 moles based on 1 mole of a; either b or c, or
both b+c (when both are present) are present in a molar ratio of
a:b or a:c or a:(b+c) of 0.1-100.
2. The method of claim 1, wherein about 1-2,000 ppm of said
antifoulant is brought into contact with said hydrocarbon stream,
based upon 1 million parts of said stream by weight.
3. The method of claim 1, wherein said polymer is a copolymer of
acrylic acid (AA) acid/allyl ether or (AA)/allyl hydroxylated alkyl
ether.
4. (canceled)
5. The method of claim 1, wherein said polymer is a terpolymer of
AA/AHP SE/styrene.
6. The method of claim 1, wherein said polymer is a copolymer of
AA/allylpolyethyleneglycol ether or AA/ethoxylated allyl ether.
7. The method of claim 6, wherein said ethoxylated allyl ether is
allylpolyethyoxy (10) sulfate.
8. The method of claim 1, wherein said polymer is a terpolymer of
AA/AHPSE/ammonium allylpolyethoxy (10) sulfate or a copolymer of
AA/lower alkyl (C.sub.1-C.sub.4) acrylate.
9. The method of claim 8, wherein said lower alkyl
(C.sub.1-C.sub.4) acrylate is an hydroxy alkyl acrylate.
10. The method of claim 9, wherein said hydroxy alkyl acrylate is 2
hydroxypropyl acrylate (HPA).
11. The method of claim 1, wherein said polymer is a terpolymer of
AA/HPA/AHP SE/styrene.
12. (canceled)
13. The method of claim 1, wherein the antifoulant is added to the
hydrocarbon stream simultaneously with the base wash or is added to
the hydrocarbon stream in a hydrocarbon charge line to a basic wash
tower or is added to the hydrocarbon stream in an input line to or
recycle line from a basic wash tower, or a recycle line from a
basic wash tower or to a caustic solution pipeline line.
14. The method of claim 1, wherein said hydrocarbon stream is a
methanol to olefin (MTO) process stream or a cracked hydrocarbon
stream from the pyrolysis of hydrocarbons.
15. The method of claim 14, wherein the cracked hydrocarbon stream
is from the pyrolysis of ethane, propane, butane, naphtha, or
mixtures thereof.
16. The method of claim 1, wherein the basic wash has a pH greater
than 7.0 and comprises sodium hydroxide, potassium hydroxide,
sodium carbonate, sodium hydrocarbonate, potassium hydrocarbonate,
organic amine, or an alkanolamine.
17. The method according to claim 1, wherein the antifoulant
further comprises another carbonyl scavenger, said another carbonyl
scavenger comprises at least one compound selected from the group
consisting of alcohol amines, alkyl amines, keto amines, amino
acids, hydrazide compounds, hydroxylamines, reducing sugars,
hydroxybenzenes, acetoacetate ester compounds, lactams, oxidizers,
and reducers.
18. (canceled)
19. A water soluble or water dispersible polymer composition having
the structure E .sub.a G .sub.z F .sub.d Formula VI wherein a, z,
and d are all present; E is a repeat unit remaining after
polymerization of an ethylenically unsaturated compound, F is a
repeat unit remaining after polymerization of an ethylenically
unsaturated hydrophobic moiety; wherein the molar ratio of d:a is
about 0.1-0.8 moles of d:1 mole a; z is present in an amount of a:z
of 0.1-100 moles a per 1 mole z; G is a repeat unit chosen from
VIa, VIb, VIc, or VId or mixtures thereof, wherein VIa is
##STR00016## VIb is ##STR00017## wherein R.sub.1 is H or lower
(C.sub.1-C.sub.4) alkyl, R.sub.2 is a hydroxy substituted alkyl or
alkylene moiety having from about 1-6 carbon atoms, X is an anionic
radical selected from the group consisting of SO.sub.3, OSO.sub.3,
PO.sub.3, OPO.sub.3, or COO; M is H or hydrogens or any water
soluble cationic moiety that counterbalances the valence of the
anionic radical X; Q is chosen from C.sub.1-C.sub.3 alkylene or
carbonyl, m is 0 or 1; R.sub.3 is CH.sub.2--CH.sub.2--O .sub.n;
--CH.sub.2CHCH.sub.3O .sub.n wherein n=1 to 100; or R.sub.3 is
hydroxylated lower (C.sub.1-C.sub.4) alkylene; and R.sub.4, is H,
OH, SO.sub.3M, OSO.sub.3M, PO.sub.3M, OPO.sub.3M, or CO.sub.2M; VIc
is ##STR00018## wherein R.sub.1 is as defined above, R.sub.5 is NH
or O; R.sub.6 is lower (C.sub.1-C.sub.4) alkyl or alkylene or lower
(C.sub.1-C.sub.4) hydroxy substituted alkyl or alkylene; X and M
are as defined above; and VId is ##STR00019## wherein R.sub.7 is
CH.sub.2 or benzyl, and X and M are defined above.
20. The polymer composition as recited in claim 19, wherein E is
acrylic acid or water soluble salt form thereof (AA).
21. The polymer composition of claim 20, wherein F is styrene.
22. The polymer composition of claim 21, wherein G is VIc and
R.sub.5 is NH, or O; R.sub.6 is 2-methyl-1-propane or 2
hydroxypropyl, and X is SO.sub.3.
23. (canceled)
24. The polymer composition of claim 21, wherein G is VIa and
R.sub.2 is 2 hydroxypropyl and X is SO.sub.3.
25. The polymer composition of claim 21, wherein G is VIb and Q is
CH.sub.2, m=1; R.sub.3 is CH.sub.2--CH.sub.2--O .sub.n and R.sub.4
is SO.sub.3M.
26. The polymer composition of claim 21, wherein G is VIb and
wherein Q=CH.sub.2, m=O; R.sub.3 is CH.sub.2CH.sub.2--O .sub.n and
R.sub.4 is OSO.sub.3M.
27. The polymer composition of claim 21, wherein G comprises both
VIa and VIb and wherein R.sub.2 is hydroxypropyl; X is SO.sub.3; Q
is CH.sub.2; m=O; R.sub.3 is CH.sub.2CH.sub.2--O .sub.n and R.sub.4
is OSO.sub.3M.
28. The polymer composition of claim 21, wherein G is VId; wherein
R.sub.7 is benzyl or CH.sub.2, and X is SO.sub.3.
29. (canceled)
30. A water soluble terpolymer composition comprising acrylic acid
or acrylic acid salt (AA) repeat units, hydrophobic monomeric
repeat units, and a third repeat unit selected from the group
consisting of acrylamide repeat units, allyl ether repeat units,
lower alkyl (C.sub.1-C.sub.4) acrylate repeat units, ethoxylated or
propoxylated allyl repeat units, allyl polyethylene glycol ether
repeat units, sulfonated styrene repeat units, and allyl sulfonic
acid repeat units.
31. The water soluble terpolymer composition as recited in claim
30, wherein said hydrophobic monomeric repeat units comprise
styrene.
32. The water soluble terpolymer composition as recited in claim
31, wherein said third repeat unit is 2-acrylamido-2-methyl-1
propane sulfonic acid (AMPS), allyl hydroxy propyl sulfonate ether
(AHPSE), allylpolyethoxy sulfonate (APES), or hydroxypropyl
acrylate (HPA).
33-36. (canceled)
Description
FIELD OF INVENTION
[0001] The invention relates to methods and compositions for
inhibiting the formation of fouling deposits in basic wash systems
of the type adapted to scrub impurities, such as those that may be
formed via aldol condensation reactions, from liquid or gas phase
hydrocarbonaceous streams.
BACKGROUND OF THE INVENTION
[0002] Olefinic compounds such as ethylene, propylene, butylene,
and amylene can be formed from methanol to olefin (MTO) or various
pyrolytic cracking processes. In these processes, a variety of
carbonyl compounds such as aldehydes and ketones are often formed.
Typically, the carbonyl compounds are found in the gas stream in
about 1 to 200 parts per million (ppm) by weight relative to the
hydrocarbon stream with concentrations of more than 1,000 ppm
sometimes encountered due to the particular feedstock and reactor
operation parameter employed for the reactions.
[0003] The hydrocarbon product stream formed via cracking or MTO
processes is cooled and sometimes compressed. The product gas
stream may be passed through a basic wash system (pH>7) to
remove acidic components such as hydrogen sulfide and carbon
dioxide. In many cases, the carbonyl compounds present, such as the
aldehydes, will undergo polymerization to form condensation
polymers known as aldol polymers or red oil. These aldol polymers
or red oil possess low solubility in the alkaline wash and the
hydrocarbon media and can deposit on wash tower tray conduits and
other internal surfaces of the process equipment leading to fouling
and eventual plugging. These deposits can restrict flow through the
equipment and can cause undesirable pressure drops, resulting in
decreased process throughput, increased operating costs, and unit
shut down for periodic cleaning.
[0004] The basic wash systems in which treatment is required to
inhibit such polymer based fouling include amine acid gas scrubber,
such as MEA, DEA, isopropyl amine, butyl amine, etc., and caustic
wash systems.
[0005] Generally, the basic washing entails contacting the gaseous
olefins with an aqueous basic solution in a wash tower to remove
hydrogen sulfide, carbon dioxide, and other oxygenated compounds
therefrom. The basic washing is particularly appropriate for the
basic washing process which follows the pyrolytic cracking of such
hydrocarbons as ethane, propane, butane, naphtha, and mixtures
thereof to produce the corresponding gaseous ethylene, propylene,
butadiene, and the like, or follows the MTO production process
containing the carbonyl and other contaminants.
SUMMARY OF THE INVENTION
[0006] In one embodiment of the invention, methods are provided for
inhibiting the formation of fouling materials comprising contacting
a hydrocarbon media containing aldehyde compounds with an
antifoulant. The hydrocarbon media is treated in a basic wash
system. The antifoulant may comprise a polymer having repeat units
characterized by the formula
##STR00001##
wherein a must be present, b or c or b+c is present and d may or
may not be present; E is a repeat unit remaining after
polymerization of an ethylenically unsaturated compound and can be,
for example, (meth) acrylic acid or (meth) acrylamide; each R.sub.1
is independently chosen from H or lower (C.sub.1-C.sub.4) alkyl;
R.sub.2 is a hydroxy substituted alkyl or alkylene moiety having
from about 1-6 carbon atoms, X is an anionic radical selected from
the group consisting of SO.sub.3, OSO.sub.3, PO.sub.3OPO.sub.3 or
COO; M is one or more hydrogens or any water soluble cationic
moiety that counterbalances the valence of the anionic radical X
and can be Ca, Na, K, NH.sub.4, etc.; F is an ethylenically
unsaturated hydrophobic moiety such as styrene and its derivatives,
acrylonitrile, olefin with (C.sub.1-C.sub.18) alkyl group, alkyl
(meth) acrylate; Q in repeat unit c is chosen from C.sub.1-C.sub.3
alkylene or carbonyl, m is 0 or 1, R.sub.3 is CH.sub.2--CH--O
.sub.n or CH.sub.2--CHCH.sub.3--O .sub.n wherein n is from 1 to
about 100 or R.sub.3 is CH.sub.2--CHOH or
CH.sub.2--CH--(OH)--CH.sub.2; R.sub.4 is H, OH, SO.sub.3M,
OSO.sub.3M, PO.sub.3M, OPO.sub.3M, or CO.sub.2M; with the proviso
that when d is present it is present in an amount of 0.01-0.8 moles
based on 1 mole of a; either b or c, or both b+c (when both are
present) are present in a molar ratio of a:b or a:c or a:(b+c) of
0.1-100, or in some exemplary embodiments 1-10.
[0007] In certain embodiments, the polymeric antifoulant may
comprise a copolymer of acrylic acid (AA) and allyl ether. In other
embodiments of the invention, the polymeric foulant may be an
acrylic acid (AA) allylhydroxylated alkyl ether, also referred to
as 1-propane sulfonic acid, 2-hydroxy-3 (2-propenyl oxy) mono
sodium salt (AHPSE).
[0008] The polymeric antifoulant may also be a terpolymer of
AA/AHPSE/styrene or it may be, in certain embodiments, a copolymer
of acrylic acid and an allyl polyethylene glycol ether. In some
cases, the polymer may comprise a copolymer of acrylic acid with an
ethoxylated allyl ether. In other embodiments, the copolymer may
comprise acrylic acid and lower alkyl acrylates such as hydroxy
substituted alkyl acrylates.
[0009] In another aspect of the invention, novel water soluble or
water dispersible polymer compositions are provided having the
structure
E .sub.a G .sub.z F .sub.d Formula VI
wherein a, z, and d are all present; E is a repeat unit remaining
after polymerization of an ethylenically unsaturated compound, F is
a repeat unit remaining after polymerization of an ethylenically
unsaturated hydrophobic moiety; wherein the molar ratio of d:a is
about 0.1-0.8 moles of d:1 mole a; z is present in an amount of a:z
of 0.1-100, 1-10 moles a per 1 mole z and in some embodiments is
present in an amount of 1-10 moles of a per mole z; G is a repeat
unit chosen from VIa, VIb, VIc, or VId or mixtures thereof, wherein
VIa is
##STR00002##
VIb is
##STR00003##
[0010] wherein R.sub.1 is H or lower (C.sub.1-C.sub.4) alkyl,
R.sub.2 is a hydroxy substituted alkyl or alkylene moiety having
from about 1-6 carbon atoms, X is an anionic radical selected from
the group consisting of SO.sub.3, OSO.sub.3, PO.sub.3, OPO.sub.3,
or COO; M is H or hydrogens or any water soluble cationic moiety
that counterbalances the valence of the anionic radical X; Q is
chosen from C.sub.1-C.sub.3 alkylene or carbonyl, m is 0 or 1;
R.sub.3 is CH.sub.2--CH.sub.2--O .sub.n; --CH.sub.2CHCH.sub.3O
.sub.n wherein n=1 to 100; or R.sub.3 is hydroxylated lower
(C.sub.1-C.sub.4) alkylene; and R.sub.4i, is H, OH, SO.sub.3M,
OSO.sub.3M, PO.sub.3M, OPO.sub.3M, or CO.sub.2M;
VIc is
##STR00004##
[0011] wherein R.sub.1 is as defined above, R.sub.5 is NH or O;
R.sub.6 is lower (C.sub.1-C.sub.4) alkyl or alkylene or lower
(C.sub.1-C.sub.4) hydroxy substituted alkyl or alkylene; X and M
are as defined above; and VId is
##STR00005##
wherein R.sub.7 is CH.sub.2 or benzyl, and X and M are defined
above.
[0012] In further aspects of the invention, novel water soluble
terpolymer compositions are provided that comprise acrylic acid or
acrylic acid salt repeat units, a hydrophobic repeat unit such as
styrene and its derivatives, acrylonitrile, olefin with
(C.sub.1-C.sub.18) alkyl group, alkyl (meth) acrylate, and a third
repeat unit selected from the group consisting acrylamide repeat
units, allyl ether repeat units, lower alkyl (C.sub.1-C.sub.4)
acrylate repeat units, ethoxylated or propoxylated allyl repeat
units, allyl polyethylene glycol ether repeat units, sulfonated
styrene repeat units, and allyl sulfonic acid repeat units.
Terpolymers wherein the hydrophobic monomeric repeat unit comprises
styrene may be mentioned as exemplary.
BRIEF DESCRIPTION OF THE DRAWING
[0013] The invention is further described in connection with the
drawings wherein:
[0014] FIG. 1 is a microphotograph of filter cakes resulting from
candidate antifoulant treatments as referred to in Example 3.
DETAILED DESCRIPTION
[0015] In one aspect of the invention, methods and compositions are
provided to inhibit the formation of polymeric based fouling
deposits during the basic washing of hydrocarbons contaminated with
carbonyl compounds which lead to the formation of undesirable
insoluble polymer contaminants. In one embodiment, the antifoulant
compound is a polymer having the Formula I
##STR00006##
wherein a must be present and either b or c or both b and c are
present; d may or may not be present. In one embodiment, d is
present. E is a repeat unit remaining after polymerization of an
ethylenically unsaturated compound including carboxylic acids such
as acrylic acid, sulfonic acid, phosphonic acid, or amide of such
acid or mixtures thereof; E can be for example (meth) acrylic acid
or (meth) acrylamide; each R.sub.1 is independently chosen from H
or lower (C.sub.1-C.sub.4) alkyl. R.sub.2 is a hydroxy substituted
alkyl or alkylene moiety having from about 1-6 carbon atoms, X is
an anionic radical selected from the group consisting of SO.sub.3,
OSO.sub.3, PO.sub.3, OPO.sub.3, or COO; M is one or more hydrogens
or any water soluble cationic moiety that counterbalances the
valence of the anionic radical X including but not limited to Na,
K, Ca, or NH.sub.4; F is an ethylenically unsaturated hydrophobic
moiety such as styrene, and its derivatives, acrylonitrile, olefin
with (C.sub.1-C.sub.18) alkyl group, alkyl (meth) acrylate.
[0016] Q in repeat unit c is chosen from C.sub.1-C.sub.3 alkylene
or carbonyl; m is 0 or 1 meaning that O may or may not be present,
R.sub.3 is CH.sub.2--CH.sub.2--O .sub.n CH.sub.2--CHCH.sub.3--O
.sub.n wherein n ranges from about 1 to 100, including 1 to 20, or
R.sub.3 is hydroxylated lower (C.sub.1-C.sub.4) alkylene such as
CH.sub.2--CH(OH) or CH.sub.2--CH(OH)--CH.sub.2; R.sub.4 is H, OH,
SO.sub.3M, OSO.sub.3M, PO.sub.3M, OPO.sub.3M, CO.sub.2M or mixtures
thereof with M being previously defined.
[0017] In Formula I above, when d is present, it is present in an
amount of about 0.01-0.8 moles based on 1 mole of a. Either b or c,
or both b or c if both are present, are present in a monomer ratio
of a:b or a:c or a:(b+c) of 0.1-100, including 1-10. The molecular
weight of polymers as set forth in Formula I is not critical as
long as the polymer is water soluble or water dispersible. In some
embodiments, the molecular weight can range from about 500-50,000
(Mn).
[0018] Exemplary polymers that may be used to inhibit fouling in
hydrocarbonaceous media containing carbonyl compounds such as
aldehydes include acrylic acid/allyl ether copolymers such as
acrylic acid/allyl hydroxylated alkyl copolymers and water soluble
salt forms thereof such as acrylic acid/1-propane sulfonic acid, 2
hydroxy-3(2-propenyl oxy) mono sodium salt also referred sometimes
to as acrylic acid/allyl hydroxypropyl sulfonate ether (AHPSE).
Additionally, terpolymers comprising acrylic acid/AHPSE/and styrene
repeat units can also be mentioned.
[0019] Acrylic acid/ethoxylated allyl ethers such as those
enumerated in U.S. Pat. No. 7,094,852 can also be mentioned as
exemplary. These include acrylic acid/allylpolyethoxylated
copolymers such as acrylic acid/allylpolyethoxy (10) sulfate (APES)
and others. Also, acrylic acid/allyl polyethylene glycol ethers
such as those set forth in U.S. Pat. No. 6,641,754 are noteworthy.
One particular terpolymer of interest is a terpolymer of acrylic
acid/AHPSE/and ammonium allyl polyethoxy (10) sulfate.
[0020] Other exemplary polymers can include water soluble or water
dispersible acrylic acid/hydroxylated alkyl acrylates such as
acrylic acid/2 hydroxypropylacrylate copolymers. Certain of the
exemplary polymers are shown in Formula II-V following:
##STR00007##
[0021] The copolymer shown in Formula II may be referred to as
AA/AHPSE (as herein used AA denotes acrylic acid and/or its various
water soluble salt forms), and AHPSE has been previously referred
to.
##STR00008##
The terpolymer shown in Formula III may be referred to as
AA/AHPSE/styrene.
##STR00009##
This may be referred to as AA/AHPSE/allylpolyethoxy(10) sulfate
(APES).
##STR00010##
AA/AHP SE/APES/Styrene
[0022] The antifoulant polymers may be fed to the basic (pH>7)
wash tower itself or to input or recycle lines in communication
with the wash tower. In some cases, the antifoulant is dosed into
the caustic solution feed or recycle lines that are in fluid
communication with the wash tower. Typically, the antifoulant
polymers are fed to the hydrocarbon stream (charge gas) in an
amount of 1-2,000 ppm by weight relative to the hydrocarbon stream.
In other embodiments, the antifoulants are fed in an amount of
about 1-1,000 ppm. In one embodiment, the feed rate may be from
about (0.01-100)X of the antifoulant wherein X is the molar
concentration of aldehyde or ketone in the charge gas.
[0023] In Formulae III and IV, a, b, and c are, independently, zero
or a positive integer such that the molecular weight of the
molecule is less than about 500,000 Daltons, such as from
500-500,000 Daltons. In Formula V, a, b, c, and d, are
independently zero or positive integers such that the molecular
weight of the molecule is less than about 500,000 Daltons.
[0024] In some aspects of the invention, the antifoulant is
conjointly used with other carbonyl scavengers which can include
alcohol amines such as triisopropanolamine, diglycolamine,
aminomethylpropanol, N, N-diethylethanolamine,
monoisopropanolamine, monoethanolamine, diethanolamine,
triethanolamine, dimethylaminoethanol, and etc.; alkyl amines, such
as phenothiazine, diazacyclohexane, N--N-dimethyldodecylamine,
N,N'-bis(1-methylpropyl)-1,4-phenylenediamine,
aminoethylpiperazine, 1,2-dianilinoethane, diethylenetriamine and
etc.; keto-amines, such as triacetonamine; amino acids, such as 6
amino caproic acid; hydrazide compounds, such as
1,2-diformylhydrazine, carbohydrazide, N-methyl-hydrazide, oxalyl
dihydrazide, chlorobenzhydrazide, aminobenzhydrazide, benzoic
hydrazide, and etc.; hydroxylamine compounds, such as
N,N-diethylhydroxylamine, isopropyl hydroxylamine, hydroxylamine
sulfate, N,N-dialkylhydroxylamine, and etc.; reducing sugars,
hydroxybenzenes, acetoacetate ester compounds, lactams, oxidizers,
such as hydroperoxide, peroxyester, percarbonate compounds and
etc.; and reducer, such as sodium borohydride, sodium (bi)sulfite
and etc. These additional compounds may be present in an amount of
about 1 to about 2,000 ppm by weight relative to the hydrocarbon
stream.
[0025] In another aspect of the invention, novel water soluble or
water dispersible polymers are provided that are useful as deposit
control, scale inhibition and anti-foulant treatments in
hydrocarbon media. As an example, these polymers may be used to
inhibit carbonyl based polymer deposits that may otherwise form in
basic washing systems employed in MTO and olefin cracking
processes. The antifoulant polymers generally have the Formula
VI
E .sub.a G .sub.z F .sub.d Formula VI
wherein a, z, and d are all present. E and F are as previously
defined in conjunction with Formula I. G is VIa, VIb, VIc, or VId
or mixtures thereof, or G is either or both of the repeat unit
moieties of b and c as set forth in Formula I, wherein
VIa is
##STR00011##
[0026] VIb is
##STR00012##
[0027] wherein R.sub.1 is H or lower (C.sub.1-C.sub.4) alkyl,
R.sub.2 is a hydroxy substituted alkyl or alkylene moiety having
from about 1-6 carbon atoms, X is an anionic radical selected from
the group consisting of SO.sub.3, OSO.sub.3, PO.sub.3, OPO.sub.3,
or COO; M is H or hydrogens or any water soluble cationic moiety
that counterbalances the valence of the anionic radical X; Q is
chosen from C.sub.1-C.sub.3 alkylene or carbonyl, m is 0 or 1;
R.sub.3 is CH.sub.2--CH.sub.2--O .sub.n; --CH.sub.2CHCH.sub.3O
.sub.n wherein n=1 to 100; or R.sub.3 is hydroxylated lower
(C.sub.1-C.sub.4) alkylene; and R.sub.4 is H, OH, SO.sub.3M,
OSO.sub.3M, PO.sub.3M, OPO.sub.3M, or CO.sub.2M or mixtures thereof
with M being as previously defined;
VIc is
##STR00013##
[0028] wherein R.sub.1 is as defined above, R.sub.5 is NH or O;
R.sub.6 is lower (C.sub.1-C.sub.4) alkyl or alkylene or lower
(C.sub.1-C.sub.4) hydroxy substituted alkyl or alkylene; X and M
are as defined above; and VId is
##STR00014##
wherein R.sub.7 is CH.sub.2 or benzyl, and X and M are defined
above.
[0029] In Formula VI, the molar ratio of d:a is about 0.1-0.8 moles
of d per 1 mole a; z is present in an amount of a:z of 0.1-100
moles a per 1 mole z with certain embodiments having 1-10 moles a
per 1 mole z.
[0030] Exemplary polymers in accordance with Formula VI include
acrylic acid (AA)/2-acryloylamino-2-methyl-1-propanesulfonic acid
(AMPS)/styrene terpolymers (i.e., Formulae VI and VIc) wherein E is
AA, R.sub.5 is NH, R.sub.6=2-methylpropane, and X is
SO.sub.3.sup.-; F is styrene. Additionally, Formula VI terpolymers
of AA/allysulfonic acid/styrene can be noted wherein R.sub.7 in
Formula VId is CH.sub.2 with X being SO.sub.3.sup.-. Also, in some
embodiments, R.sub.7 can comprise a benzyl moiety with X being
SO.sub.3.sup.-, namely AA/sulfonated styrene/styrene
terpolymers.
[0031] Further, other terpolymeric combinations within the ambit of
Figure VI include AA/AHPSE/styrene terpolymers, AA/lower alkyl
(C.sub.1-C.sub.4) acrylate/styrene terpolymers, AA/hydroxylated
alkyl (C.sub.1-C.sub.4) acrylate/styrene terpolymers, AA/allyl
polyethylene glycol (PEG) ether/styrene terpolymers; AA/allyl
polyethyoxy sulfate (APES)/styrene terpolymers and AA/PEG allyl
ether/APES/styrene polymers.
[0032] The polymers of the invention can be prepared via radical
chain addition polymerization of the requisite monomers. The
reaction may proceed, for example, under conventional solution
polymerization techniques. The requisite monomers may be mixed with
water and alcohol. Polymerization initiators such as the persulfate
initiators, peroxide initiators, etc., may be employed. The
resulting copolymers, terpolymers, quad polymers, etc. (at least
four monomeric repeat units) may be isolated by well known
techniques such as distillation, etc., or the polymer may simply be
used in aqueous solution.
[0033] For example, a terpolymer in accordance with Formula III can
be prepared as follows:
[0034] 1. Charge initial 97.7 g (sodium 1-allyloxy 2-hydroxy propyl
sulfonate) and 50 g DI water into the reactor and set up the
reactor
[0035] 2. Record reactor weight
[0036] 3. Sparge with N.sub.2 for 10 minutes
[0037] 4. Switch to a nitrogen blanket and heat to 90.degree.
C.
[0038] 5. Start a simultaneous co-feed of the following reagents
[0039] 39 g Acrylic Acid over 150 minutes [0040] 5 g Styrene over
60 minutes [0041] 25 g Sodium persulfate (5%) over 150 minutes
[0042] 6. After feed, hold at 90.degree. C. for 90 minutes
[0043] 7. Cool to room temperature and add caustic solution (50%
NaOH solution) and dilution water
[0044] 8. Measure reactor weight and solid content.
[0045] In some aspects of the invention, a water soluble terpolymer
composition is provided that comprises: i) acrylic acid or acrylic
acid salt repeat units, ii) a hydrophobic repeat unit such as
styrene repeat units, and a third repeat unit iii). The third
repeat unit may be selected from the group consisting of acrylamide
repeat units, allyl ether repeat units, lower alkyl
(C.sub.1-C.sub.4) acrylate repeat units, ethoxylated or
protoxylated allyl repeat units, allyl polyethylene glycol ether
repeat units, sulfonated styrene repeat units, and allyl sulfonic
acid repeat units.
[0046] In some cases, the third repeat unit may be
2-acrylamido-2-methyl-1 propane sulfonic acid (AMPS). In other
cases, the third repeat unit may be allyl hydroxypropyl sulfonate
ether (AHPSE). Still, in other aspects, the third repeat unit may
comprise allylpolyethoxy sulfonate (APES). Additionally, the third
repeat unit may, in some aspects of the invention, comprise
hydroxypropyl acrylate (HPA). In other embodiments, this third
repeat unit may comprise AHPSE, and a fourth repeat unit may be
present. This fourth repeat unit may comprise APES.
[0047] These terpolymer comprising repeat units i), ii), and iii)
may comprise monomeric repeat units of about 0.01-0.8 moles ii) per
mole of i). The repeat unit iii) may be present in an amount of
about 0.1-100, including 1-10 moles i) per mole of iii). Molecular
weight of these polymers may range from about 500-500,000 (Mn).
[0048] The invention will be described in conjunction with the
following specific examples which are to be regarded as
illustrative and not as restricting the scope of the invention.
EXAMPLES
Example 1
[0049] In order to simulate carbonyl compound fouling in caustic
towers and to evaluate the dispersion capability and fouling
inhibition of candidate compounds, the following procedure was
employed.
TABLE-US-00001 TABLE 1 Components of simulated carbonyl compound
fouling and treatment Components Concentration NaOH 10% (w/w)
Dispersant/inhibitor 0-1000 ppm Acetaldehyde 2000 ppm
25 ml 10% NaOH and no dispersant (blank)/1000 ppm dispersant were
charged into a 30 ml glass bottle. The bottle was capped and the
solution was mixed. Then 2000 ppm aldehyde was dosed into the
bottles and mixed after the bottle had been capped tightly. After
that, the mixture was incubated in a water bath at 50.degree. C.
for 24 hours. Finally, the mixture appearance of the bottle was
recorded immediately when being taken out of the water bath without
shaking. Thus, the sample untreated and samples tested with the
candidates listed in Table 2 were tested. Results are shown in
Table 3.
[0050] Dispersant/inhibitor candidates were selected. Some of these
included known dispersant/inhibitors that are commonly used to
control carbonyl based fouling. These are designated in Table 2
with the prefix "C" (comparative). Dispersant inhibitor compounds
in accordance with the invention are denoted by the prefix "N".
TABLE-US-00002 TABLE 2 Candidates of inhibitor and dispersant
Candidate Chemical C1 30% Hydroxylamine sulfate C2 45% Naphthalene
sulfonate formaldehyde condensate C3 Poly(AA/AMPS) (43% solid) C4
PAA (50% solid) C5 PMA (50% solid) C6 Sodium Ligninsulfonate (45%
solid) N1 Chemical with Formula II (37% solid) N2 Chemical with
Formula III (37% solid) N3 Chemical with Formula IV (50% solid) N4
Chemical with Formula V (51% solid)
AA=acrylic acid or salt thereof; poly (AA/AMPS)=poly (acrylic
acid/2-acrylamido-2-methylpropane sulfonic acid); PAA=polyacrylic
acid, PMA=poly maleic acid; N.sub.1=poly (acrylic acid/allyl
2-hydroxypropyl sulfonate ether (AA/AHPSE)); N.sub.2=poly (acrylic
acid/AHPSE/styrene) terpolymer; N3=poly (AA/AHPSE/allylpolyethoxy
(10) sulfate (APES)); N4=poly (AA/AHPSE/APES/styrene).
[0051] Carbonyl compound fouling dispersion capability of the
common dispersants in water system was studied. The carbonyl
compound fouling was simulated and treated as Example 1. The
dispersion performance of the candidates in Table 2 was studied
under 1000 ppm product dosage by weight relative to the total
solution. Table 3 shows the test results. From the appearance, we
can conclude that the C1, C3, C4 and C5 did not show any dispersion
capability to the carbonyl compound fouling at 1000 ppm dosage. C2
and C6 possessed some dispersion capability to the formed fouling.
The sample treated with N1 resulted in a homogeneous suspension
with a little precipitation, no flocs observed. This indicates that
N1 possesses good dispersion capability to the polymeric fouling
caused by carbonyl compound, such as aldehyde in caustic tower. N2
showed the best dispersion performance without any flocs or
precipitation. The hydrophobic monomer in N2 enhances its
dispersion capability.
TABLE-US-00003 TABLE 3 Carbonyl compound fouling dispersion test
result Candidate Result Blank Severe flocs C1 Severe flocs C2 Flocs
C3 Severe flocs C4 Severe flocs C5 Severe flocs C6 Moderate Flocs
N1 Homogeneous suspension with a little precipation N2 Homogeneous
suspension N3 Homogenous suspension with a little precipitation N4
Homogenous suspension
Example 2
[0052] The carbonyl compound fouling dispersion performance of C2,
N1 and N2 was studied under dosage from 500 to 1000 ppm. The
carbonyl compound fouling was simulated and treated as Example 1.
Table 4 lists the test result. From the table, it can be observed
that N2 showed the best dispersion capability, 800 ppm dosage was
enough to keep the fouling suspension stable under lab static test
condition.
TABLE-US-00004 TABLE 4 Carbonyl compound fouling dispersion V.S.
dosage Treatment reagent 500 ppm 800 ppm 1000 ppm C2 Severe flocs
Flocs Flocs N1 Severe flocs Flocs Homogeneous suspension with a
little precipation N2 Floc Homogeneous Homogeneous suspension
suspension
Example 3
[0053] The dispersion capability was evaluated with a filtration
method. The carbonyl compound fouling was simulated and treated by
the procedures similar with Example 1. 200 ml 10% NaOH was charged
into 500 ml glass bottle and no treatment (blank) and 1000 ppm
treatment reagents, including C1, C2 and N2 were dosed into the
bottles. The bottles were capped and shaken. Then, 2000 ppm
aldehyde was dosed into the above solution and mixed. After that,
the mixture was incubated in water bath at 50.degree. C. for 24
hours immediately. Finally, the bottle was taken out, mixed and
then the suspension was filtrated with 0.8 .mu.m fiberglass filter.
FIG. 1 shows the filter cakes of the fouling treated with
corresponding chemicals. It can be observed that there was no
fouling substance kept on the surface of the filter after being
treated with N2. It shows that the fouling particle size after
being treated with N2 is smaller than 0.8 .mu.m. This indicates N2
possesses excellent capability to disperse carbonyl compound
fouling into small particles. This kind of capability can prevent
the fouling to flocculate or precipitate, so to eliminate the
jamming or blockage in the caustic tower tray or pipelines during
MTO, ethylene or propylene production process.
[0054] While this invention has been described with respect to
particular embodiments thereof, it is apparent that numerous other
forms and modifications of this invention will be obvious to those
skilled in the art. The appended claims an this invention generally
should be construed to cover all such obvious forms and
modifications which are within the true spirit and scope of the
present invention.
* * * * *