U.S. patent application number 12/055889 was filed with the patent office on 2009-10-01 for oxidative desulfurization of fuel oil.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to John Mathew Bablin, Grigorii Lev Soloveichik.
Application Number | 20090242459 12/055889 |
Document ID | / |
Family ID | 40894028 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090242459 |
Kind Code |
A1 |
Soloveichik; Grigorii Lev ;
et al. |
October 1, 2009 |
OXIDATIVE DESULFURIZATION OF FUEL OIL
Abstract
A method for purifying a sulfur-containing fuel oil comprising
(a) contacting in a first reaction mixture the sulfur-containing
fuel oil with an exogenous binary catalyst, hydrogen peroxide, and
a water-soluble acid at a temperature in a range of from about
25.degree. C. to about 150.degree. C. to provide a first oxidized
mixture; and (b) separating at least one oxidized sulfur compound
from the first oxidized mixture to provide a purified fuel oil. The
first reaction mixture may further comprise a phase transfer
catalyst. Furthermore, the sulfur-containing fuel oil may be
deasphalted prior to contacting with the catalyst, hydrogen
peroxide, and the water-soluble acid.
Inventors: |
Soloveichik; Grigorii Lev;
(Latham, NY) ; Bablin; John Mathew; (Malta,
NY) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY;GLOBAL RESEARCH
PATENT DOCKET RM. BLDG. K1-4A59
NISKAYUNA
NY
12309
US
|
Assignee: |
GENERAL ELECTRIC COMPANY
SCHENECTADY
NY
|
Family ID: |
40894028 |
Appl. No.: |
12/055889 |
Filed: |
March 26, 2008 |
Current U.S.
Class: |
208/213 |
Current CPC
Class: |
C10G 21/003 20130101;
C10G 27/12 20130101; C10G 21/00 20130101 |
Class at
Publication: |
208/213 |
International
Class: |
C10G 45/04 20060101
C10G045/04 |
Claims
1. A method for purifying a sulfur-containing fuel oil, the method
comprising: (a) contacting in a first reaction mixture the
sulfur-containing fuel oil with an exogenous binary catalyst,
hydrogen peroxide and a water-soluble acid, at a temperature in a
range of from about 25.degree. C. to about 120.degree. C. to
provide a first oxidized mixture; and (b) separating at least one
oxidized sulfur compound from the first oxidized mixture to provide
a purified fuel oil.
2. The method according to claim 1, wherein the sulfur-containing
fuel oil comprises less than 5 weight percent sulfur.
3. The method according to claim 1, wherein the sulfur-containing
fuel oil comprises less than 3 weight percent sulfur.
4. The method according to claim 1, wherein the exogenous binary
catalyst comprises a first component selected from the group
consisting of phosphate salts, and oxides, acids and salts of
molybdenum, tungsten, manganese, and combinations thereof, and a
second component selected from the group consisting of oxides and
salts of cerium, iron, vanadium, titanium, manganese, cobalt,
nickel, copper and combinations thereof.
5. The method according to claim 4, wherein the first component
comprises an oxide or a salt of manganese.
6. The method according to claim 4, wherein the second component
comprises an oxide or a salt of cobalt.
7. The method according to claim 4, wherein the second component
comprises an oxide or a salt of cerium.
8. The method according to claim 4, wherein the second component
comprises an oxide or a salt of iron.
9. The method according to claim 4, wherein the exogenous binary
catalyst comprises oxides, acids or salts of molybdenum as the
first component and oxides or salts of cerium as the second
component.
10. The method according to claim 4, wherein the exogenous binary
catalyst comprises oxides or salts of manganese as the first
component and oxides or salts of iron, cobalt, or nickel as the
second component.
11. The method according to claim 4, wherein the exogenous binary
catalyst comprises phosphate salts as the first component and
oxides or salts of iron, cobalt, or nickel as the second
component.
12. The method according to claim 4, wherein the first component
comprises an oxide, an acid or a salt of molybdenum.
13. The method according to claim 12, wherein the first component
comprises a molybdenum isopolyacid or its salt.
14. The method according to claim 1, wherein the sulfur-containing
fuel oil is deasphalted prior to contacting the sulfur-containing
fuel oil with the binary catalyst, hydrogen peroxide and the
water-soluble acid by contacting the sulfur-containing fuel with an
inert diluent.
15. The method according to claim 1, wherein the water-soluble acid
is selected from the group consisting of formic acid, acetic acid,
propionic acid, butyric acid, sulfuric acid, phosphoric acid, and
mixtures of two or more of the foregoing acids.
16. The method according to claim 1, wherein the separating is
carried out using solid-liquid extraction.
17. The method according to claim 1, wherein the separating is
carried out using liquid-liquid extraction.
18. The method according to claim 1, wherein the sulfur-containing
fuel oil comprises benzothiophene, dibenzothiophene, alkyl
substituted benzothiophenes, and alkyl substituted
dibenzothiophenes.
19. The method according to claim 1, further comprising a step of
recovering the binary catalyst.
20. The method according to claim 1, wherein the first reaction
mixture further comprises a phase transfer catalyst.
21. The method according to claim 20, wherein the phase transfer
catalyst comprises a quaternary ammonium salt or a quaternary
phosphonium salt.
22. A method for purifying a sulfur-containing fuel oil, the method
comprising: (a) contacting in a first reaction mixture the
sulfur-containing fuel oil with a hydrocarbon diluent, an exogenous
binary catalyst, hydrogen peroxide, and a water-soluble acid at a
temperature in a range of from about 25.degree. C. to about
110.degree. C. to provide a first oxidized mixture; (b) separating
at least one oxidized sulfur compound from the first oxidized
mixture; and (c) recovering the hydrocarbon diluent to provide a
purified fuel oil.
23. The method according to claim 22, wherein the exogenous binary
catalyst comprises a first component selected from the group
consisting of phosphate salts, and oxides, acids and salts of
molybdenum, tungsten, manganese, and combinations thereof, and a
second component selected from the group consisting of oxides and
salts of cerium, iron, vanadium, titanium, manganese, cobalt,
nickel, copper and combinations thereof.
24. A method for purifying a sulfur-containing fuel oil, the method
comprising: (a) contacting a sulfur-containing fuel oil comprising
benzothiophene, dibenzothiophene, alkyl substituted
benzothiophenes, and alkyl substituted dibenzothiophenes with
petroleum-ether, a exogenous binary catalyst, and oxygen at a
temperature in a range of from about 25.degree. C. to about
120.degree. C., and at a pressure in a range of from about 1
atmosphere to about 150 atmospheres to provide a first oxidized
mixture comprising sulfoxides and sulfones of benzothiophene,
dibenzothiophene, alkyl substituted benzothiophenes, and alkyl
substituted dibenzothiophenes; (b) separating at least one oxidized
sulfur compound from the first oxidized mixture; and (c) recovering
petroleum-ether to provide a purified fuel oil.
25. The method according to claim 24, wherein the exogenous binary
catalyst a first component selected from the group consisting of
phosphate salts, and oxides, acids and salts of molybdenum,
tungsten, manganese, and combinations thereof, and a second
component selected from the group consisting of oxides and salts of
cerium, iron, vanadium, titanium, manganese, cobalt, nickel, copper
and combinations thereof.
Description
BACKGROUND
[0001] The invention includes embodiments that generally relate to
a method for purifying sulfur-containing fuel oil using a catalyst,
a water-soluble acid and a peroxide.
[0002] Raw/fossil fuels, such as fuel oil including a crude oil and
oil distillates and refinery products like gasoline, kerosene,
diesel fuel, naphtha, heavy fuel oil, natural gas, liquefied
natural gas and liquefied petroleum gas, and like hydrocarbons, are
useful for a number of different processes, particularly as a fuel
source, and most particularly for use in a power plant. Virtually
all of these fuels contain relatively high levels of naturally
occurring, organic sulfur compounds, such as, but not limited to,
sulfides, mercaptans and thiophenes. Hydrogen generated in the
presence of such sulfur compounds has a poisoning effect on
catalysts used in many chemical processes, particularly catalysts
used in fuel cell processes, resulting in shortening the life
expectancy of the catalysts. When present in a feed stream in a
fuel cell process, sulfur compounds may also poison the fuel cell
stack itself. Because of the relatively high levels of sulfur
compounds that may be present in many crude fuel feed streams, it
is necessary that these feed streams be desulfurized.
[0003] Furthermore, desulfurization of fuels has become an
important problem due to the upcoming regulatory requirements that
require a reduction in current sulfur emissions. Two major tasks in
the sulfur removal from fuel include (i) the deep desulfurization
of diesel fuel (reducing S content from .about.500 parts per
million to below 15 parts per million) and, (ii) sulfur removal
from crude and heavy fuel oils used for energy production (reducing
S content from 3-4 percent to less than 0.5 percent). Conventional
hydrodesulfurization (HDS) method using hydrogen have not only been
insufficient to effect the deep desulfurization of diesel fuels but
are also relatively expensive for the direct sulfur removal from a
crude and heavy fuel oils due to high cost of hydrogen and the use
of high temperature and pressure. Alternatively oxidative
desulfurization (ODS) methods using oxidants like hydrogen
peroxide, molecular oxygen or ozone, require somewhat less
demanding operating conditions when compared to the operating
conditions employed in HDS methods. Further, where oxygen may be
used as the stoichiometric oxidant, ODS methods may be cost
competitive with HDS methods.
[0004] Thus, there exists a need for efficient and cost effective
ODS methods for sulfur removal from fuel, to provide desulfurized
fuels that meet modern engineering and regulatory standards.
BRIEF DESCRIPTION
[0005] In one embodiment, the present invention provides a method
for purifying a sulfur-containing fuel oil comprising: (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil with an exogenous binary catalyst, hydrogen peroxide, and a
water-soluble acid at a temperature in a range of from about
25.degree. C. to about 150.degree. C.1 to provide a first oxidized
mixture; and (b) separating at least one oxidized sulfur compound
from the first oxidized mixture to provide a purified fuel oil.
[0006] In another embodiment, the present invention provides a
method for purifying a sulfur-containing fuel oil comprising (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil with a hydrocarbon diluent, an exogenous binary catalyst,
hydrogen peroxide, and a water-soluble acid at a temperature in a
range of from about 50.degree. C. to about 150.degree. C. to
provide a first oxidized mixture; and (b) separating at least one
oxidized sulfur compound from the first oxidized mixture; and (c)
recovering the hydrocarbon diluent to provide a purified fuel
oil.
[0007] In yet another embodiment, the present invention provides a
method for purifying a sulfur-containing fuel oil comprising (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil comprising benzothiophene, dibenzothiophene, alkyl substituted
benzothiophenes, and alkyl substituted dibenzothiophenes with
petroleum ether, an exogenous binary catalyst, hydrogen peroxide,
and a water-soluble acid at a temperature in a range of from about
50.degree. C. to about 120.degree. C. to provide a first oxidized
mixture comprising sulfoxides and sulfones of benzothiophene,
dibenzothiophene, alkyl substituted benzothiophenes, and alkyl
substituted dibenzothiophenes; (b) separating at least one oxidized
sulfur compound from the first oxidized mixture; and (c) recovering
petroleum ether to provide a purified fuel oil.
[0008] These and other features, aspects, and advantages of the
present invention may be understood more readily by reference to
the following detailed description.
DETAILED DESCRIPTION
[0009] In the following specification and the claims, which follow,
reference will be made to a number of terms, which shall be defined
to have the following meanings.
[0010] The singular forms "a", "an", and "the" include plural
referents unless the context clearly dictates otherwise. "Optional"
or "optionally" means that the subsequently described event or
circumstance may or may not occur, and that the description
includes instances where the event occurs and instances where it
does not.
[0011] Approximating language, as used herein throughout the
specification and claims, may be applied to modify any quantitative
representation that could permissibly vary without resulting in a
change in the basic function to which it is related. Accordingly, a
value modified by a term or terms, such as "about" and
"substantially", are not to be limited to the precise value
specified. In at least some instances, the approximating language
may correspond to the precision of an instrument for measuring the
value. Here and throughout the specification and claims, range
limitations may be combined and/or interchanged, such ranges are
identified and include all the sub-ranges contained therein unless
context or language indicates otherwise.
[0012] In one embodiment, the present invention provides a method
for purifying a sulfur-containing fuel oil comprising, (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil with an exogenous binary catalyst, hydrogen peroxide, and a
water-soluble acid at a temperature in a range of from about
25.degree. C. to about 150.degree. C. to provide a first oxidized
mixture; and (b) separating at least one oxidized sulfur compound
from the first oxidized mixture to provide a purified fuel oil.
[0013] In one embodiment, the sulfur-containing fuel oil is a crude
oil, for example Saudi sweet crude oil, West Texas Intermediate
crude oil, Dubai crude oil, and Brent crude oil. In an alternate
embodiment, the sulfur-containing fuel oil is a crude oil, which
has been subjected to asphaltene removal. In one embodiment, the
sulfur-containing fuel oil is a distillate or other refinery
products of a crude oil like gasoline, kerosene, diesel fuel,
naphtha, heavy fuel oil, natural gas, liquefied natural gas and
liquefied petroleum gas. In one embodiment, the sulfur-containing
fuel oil comprises dibenzothiophene, benzothiophene, alkyl
substituted dibenzothiophenes, and alkyl substituted
benzothiophenes.
[0014] In one embodiment, the sulfur-containing fuel oil comprises
less than 5 weight percent sulfur based on the weight of
sulfur-containing fuel oil. In another embodiment, the
sulfur-containing fuel oil comprises less than 3 weight percent
sulfur based on the weight of sulfur-containing fuel oil. In
another embodiment, the sulfur-containing fuel oil comprises less
than 2 weight percent sulfur based on the weight of
sulfur-containing fuel oil.
[0015] As used herein the phrase "exogenous binary catalyst" means
an "external binary catalyst" that is combined in a first reaction
mixture with a sulfur-containing fuel oil. In one embodiment, the
exogenous binary catalyst comprises a first component, a catalyst
and a second component, a promoter. In one embodiment, the binary
catalyst comprises a first component selected from the group
consisting of phosphate salts, and oxides, acids and salts of
molybdenum, tungsten, manganese, and combinations thereof, and the
second component is selected from the group consisting of oxides
and salts of cerium, iron, vanadium, titanium, manganese, cobalt,
nickel, copper and combinations thereof In another embodiment, the
first component comprises an oxide or a salt of molybdenum. In
another embodiment, the molybdenum containing first component is a
molybdenum isopolyacid or heteropolyacid or its salt with different
cations, for example, ammonium or alkali metal. The isopolyacid
means a polyacid having a polynuclear structure wherein a single
oxo-acid is condensed. The heteropolyacid means a polyacid having a
polynuclear structure wherein two or more kinds of oxo-acids may be
condensed. The heteropolyacid has a structure comprising a
condensed structure of an acid forming the skeleton (skeleton acid)
and a small number of other kinds of atoms (hetero atom) contained
in the center thereof and the like. In yet another embodiment, the
first component comprises an oxide or a salt of manganese. In
another embodiment, the second component comprises an oxide or a
salt of cobalt. In yet another embodiment, the second component
comprises an oxide or a salt of cerium. In still yet another
embodiment, the second component comprises an oxide or a salt of
iron.
[0016] In one embodiment, the exogenous binary catalyst may
comprise oxides or salts of molybdenum as the first component and
oxides or salts of cerium as the second component. In another
embodiment, the binary catalyst may comprise oxides or salts of
manganese as the first component and oxides or salts of iron,
cobalt, or nickel as the second component. In yet another
embodiment, the binary catalyst may comprise a phosphate salt, for
example ammonium hydrophosphate as the first component and oxides
or salts of iron, cobalt, or nickel as the second component.
[0017] In one embodiment, the total amount of the first component
and the second component used in the first reaction mixture is in a
range of from about 0.5 weight percent to about 10 weight percent
based on the amount of sulfur-containing fuel oil. In another
embodiment, the total amount of the first component and the second
component used in the first reaction mixture is in a range of from
about 0.5 weight percent to about 5 weight percent based on the
amount of sulfur-containing fuel oil. In yet another embodiment,
the total amount of the first component and the second component
used in the first reaction mixture is in a range of from about 1
weight percent to about 3 weight percent based on the amount of
sulfur-containing fuel oil.
[0018] In one embodiment, the atomic ratio of the first component
to the second component is 6:1. In another embodiment, the atomic
ratio of the first component is 9:1. In yet another embodiment, the
atomic ratio of the first component to the second component is
12:1. In one embodiment, a physical mixture of the first and the
second components may be used as the binary catalyst. In another
embodiment, a pre-synthesized complex compound comprising the first
and the second components, for example a heteropolyanion salt may
be used as the exogenous binary catalyst.
[0019] In one embodiment, the water-soluble acid may be selected
from the group consisting of formic acid, acetic acid, propionic
acid, butyric acid, sulfuric acid, phosphoric acid, and mixtures of
two or more of the foregoing acids. In one embodiment, the acid is
acetic acid. In another embodiment, the acid is formic acid. In yet
another embodiment, the acid is sulfuric acid. In one embodiment,
acetic acid anhydride may be used to generate acetic acid in situ
in the first reaction mixture.
[0020] In one embodiment, the amount of water-soluble acid employed
in the oxidation reaction is in a range of from about 15 volume
percent to about 40 volume percent based on the amount of the
sulfur-containing fuel oil. In another embodiment, the amount of
water-soluble acid employed in the oxidation reaction is in a range
of from about 20 volume percent to about 35 volume percent based on
the amount of the sulfur-containing fuel oil. In another
embodiment, the amount of water-soluble acid employed in the
oxidation reaction is in a range of from about 25 volume percent to
about 30 volume percent based on the amount of the
sulfur-containing fuel oil.
[0021] In one embodiment, the amount of hydrogen peroxide
(calculated as 100 percent) employed in the oxidation reaction is
in a range of from about 4 weight percent to about 20 weight
percent based on the amount of the sulfur-containing fuel oil. In
another embodiment, the amount of hydrogen peroxide employed in the
oxidation reaction is in a range of from about 5 weight percent to
about 15 weight percent based on the amount of the
sulfur-containing fuel oil. In yet another embodiment, the amount
of hydrogen peroxide employed in the oxidation reaction is in a
range of from about 6 weight percent to about 10 weight percent
based on the amount of the sulfur-containing fuel oil. In one
embodiment, hydrogen peroxide may be added as an aqueous solution
having a concentration in a range of from about 15 weight percent
to about 30 weight percent. In various embodiments, hydrogen
peroxide may be added to the first reaction mixture using methods
known to one skilled in the art, such as for example, in a
continuous manner or in portions.
[0022] In one embodiment, the at least one oxidized sulfur compound
may be separated from the first oxidized mixture using a
solid-liquid extraction process, for example an adsorption process,
to provide the purified fuel oil. In one embodiment, the at least
one oxidized sulfur compound may be separated from the first
oxidized mixture using a liquid-liquid extraction process, to
provide the purified fuel oil. One skilled in the art can easily
determine the process and the conditions required to achieve
satisfactory separation.
[0023] In one embodiment, the method for purifying the
sulfur-containing fuel oil further comprises a step of recovering
the binary catalyst. In one embodiment, the binary catalyst is
recovered from the first oxidized mixture by filtration or
centrifuging/decantation, using methods known to one skilled in the
art.
[0024] In one embodiment, the first oxidized mixture is contacted
with a porous silica adsorbent material, wherein the adsorbent
material is characterized by a Brunauer-Emmett-Teller (BET) surface
area value (total) of at least about 15 m.sup.2/g; and a
Barrett-Joyner-Halenda (BJH) pore volume (total) of at least about
0.5 cc/g. Such porous adsorbent materials and their use are
described in copending U.S. patent application Ser. No. 11/934298
filed Nov. 2, 2007 which is incorporated herein by reference in its
entirety. In instances wherein the sulfur-containing fuel oil
comprises other metallic impurities such as vanadium compounds,
such contact results in removal of these other metallic impurities
or their oxidation products from the first oxidized mixture.
[0025] In another embodiment, the first reaction mixture further
comprises a phase transfer catalyst. In one embodiment, the phase
transfer catalyst comprises a quaternary ammonium salt or a
phosphonium salt. Non-limiting examples of suitable phase transfer
catalysts may be selected from the group consisting of
methyltrioctylammonium chloride (Aliquat 336.TM.),
tetraalkylammonium bromide, trialkylmethylammonium bromide, and
hexaethylguanidium bromide. In another embodiment, the phase
transfer catalyst comprises a quaternary ammonium or a phosphonium
salt comprising an heteropolyanion
M.sup.1.sub.nM.sup.2.sub.mO.sup.q.sub.p, wherein M.sup.1 is
selected from the group consisting of phosphorus, cerium, vanadium,
manganese, iron, and cobalt, M.sup.2 is selected from the group
consisting of molybdenum, tungsten and vanadium or their mixture,
"n" is an integer having a value 1 to 2, "m" is an integer having a
value 6 to 18, "p" is an integer having a value 24 to 62, and "q"
is an integer having a value 3 to 6.
[0026] In one embodiment, the amount of phase transfer catalyst
used is in a range of from about 0.1 weight percent to about 10
weight percent based on the amount of sulfur-containing fuel oil.
In another embodiment, the amount of phase transfer catalyst used
is in a range of from about 0.5 weight percent to about 1 weight
percent based on the amount of sulfur-containing fuel oil. In yet
another embodiment, the amount of phase transfer catalyst used is
in a range of from about 1 weight percent to about 3 weight percent
based on the amount of sulfur-containing fuel oil.
[0027] In one embodiment, the temperature at which the oxidation
(also referred to as contacting the fuel oil with an exogenous
binary catalyst, hydrogen peroxide, and an acid at a temperature in
a range of from about 25.degree. C. to about 150.degree. C., to
provide a first oxidized mixture) is carried out is in a range of
from about 25.degree. C. to about 110.degree. C. In another
embodiment, the temperature at which the oxidation is carried out
is in a range of from about 55.degree. C. to about 95.degree. C. In
yet another embodiment, the temperature at which the oxidation is
carried out is in a range of from about 60.degree. C. to about
90.degree. C.
[0028] In another embodiment, the sulfur-containing fuel oil is
deasphalted prior to contacting the sulfur-containing fuel oil with
the binary catalyst and oxygen. Deasphalting of the
sulfur-containing fuel oil may be carried out by methods known to
one skilled in the art. Typically, deasphalting is carried out by
contacting the sulfur-containing fuel oil with an inert diluent and
filtering or centrifuging the resultant mixture to separate the
fuel oil from the insoluble asphaltenes to provide a deasphalted
fuel oil. In one embodiment, the inert diluent is selected from the
group consisting of liquid saturated hydrocarbons, liquid cyclic
hydrocarbons, and mixtures of at least two of the foregoing inert
diluents. Suitable non-limiting examples of liquid cyclic
hydrocarbons include cyclohexane, cycloheptane, and decalin.
Suitable non-limiting examples of liquid saturated hydrocarbons
include propane, butane, and petroleum ether. In one embodiment,
the method for purifying the sulfur-containing fuel oil further
comprises a step of recovering the inert diluent. In one
embodiment, the inert diluent is recovered from the first oxidized
mixture by distillation, using methods known to one skilled in the
art.
[0029] In another embodiment, the present invention provides a
method for purifying a sulfur-containing fuel oil comprising (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil with a hydrocarbon diluent, an exogenous binary catalyst,
hydrogen peroxide, and a water-soluble acid at a temperature in a
range of from about 25.degree. C. to about 150.degree. C. to
provide a first oxidized mixture; and (b) separating at least one
oxidized sulfur compound from the first oxidized mixture; and (c)
recovering the hydrocarbon diluent to provide a purified fuel
oil.
[0030] In yet another embodiment, the present invention provides a
method for purifying a sulfur-containing fuel oil comprising (a)
contacting in a first reaction mixture the sulfur-containing fuel
oil comprising benzothiophene, dibenzothiophene, alkyl substituted
benzothiophenes, and alkyl substituted dibenzothiophenes with
petroleum-ether, an exogenous binary catalyst, hydrogen peroxide,
and a water-soluble acid at a temperature in a range of from about
25.degree. C. to about 120.degree. C. to provide a first oxidized
mixture comprising sulfoxides and sulfones of benzothiophene,
dibenzothiophene, alkyl substituted benzothiophene, and alkyl
substituted dibenzothiophene; (b) separating at least one oxidized
sulfur compound from the first oxidized mixture; and (c) recovering
petroleum-ether to provide a purified fuel oil.
[0031] The following examples are intended only to illustrate
methods and embodiments in accordance with the invention, and as
such should not be construed as imposing limitations upon the
claims.
EXAMPLES
[0032] Reagents and catalysts employed herein were obtained from
Aldrich Chemical Company.
Examples 1 to 21 and Comparative Examples CE-1 to CE-11
Effect Of Oxidative Desulfurization On A Sulfur-Containing Fuel Oil
Model Mixture
[0033] Two model mixtures were prepared as described below. The
first model mixture was prepared from tetralin and benzothiophene
(BT), and dibenzothiophene (DBT) wherein the sulfur-containing
compounds were present in a 1:2 weight ratio (mixture #1). The
second model mixture was prepared from tetralin and dioctylsulfide
(DOS), BT, and DBT wherein the sulfur-containing compounds were
present in a 2:2:3 weight ratio (mixture #2). The mixture #1 was
used in Examples 1 to 16 and Comparative examples 1 to 7. The
mixture #2 was used in Examples 17 to 19 and Comparative examples 8
to 9. The model mixtures were shown to comprise about 3 weight
percent sulfur, when tested using a Varian Saturn 2000 GCMS.
[0034] 5 milliliters (ml) of a model mixture, sulfuric acid 0.6
grams (g), a catalyst 50 milligrams (mg) and a co-catalyst 5 to 25
mg; or a combination of 5 ml of model mixture, acetic acid 0.6 g, a
cataylst 50 mg, and a co-catalyst 5 to 25 mg; or a combination of 5
ml of model mixture, an acid 0.6 g, a catalyst 50 mg, a co-catalyst
5 to 25 mg, and 100 mg of a phase transfer catalyst Aliquat 336.TM.
were placed in two-dram vials equipped with magnetic cross-like
stirbars. Hydrogen peroxide (30 weight percent, 2 ml) was then
added to each of the vials and the vials were placed in a
Thermoline dry block heater and stirrer. The reaction mixture was
stirred for about 30 minutes. The vials were removed and cooled in
an ice bath. The cooled mixture was filtered through a filter
device (Whatman autovial 0.45 micron PTFE). The filtrate was
collected in a fresh vial. On standing, the filtrate separated into
a top oil layer and a bottom aqueous layer. For analysis, the top
oil layer 0.25 ml was diluted with 2.25 ml of acetonitrile
containing 0.35 weight percent of biphenyl (internal standard). The
diluted oil layer was analyzed on the Varian Saturn 2000 GCMS. The
results are provided in Table 1, Table 2, and Table 3 below.
TABLE-US-00001 TABLE 1 Conversion of BT and DBT in the reaction of
oxidation with hydrogen peroxide in the presence of exogenous
binary calaysts and sulfuric acid. Co-Catalyst Catalyst-Co-
Conversion Percentage Example Catalyst Formula mg Catalyst molar
ratio DBT DOS 1 Na.sub.2WO.sub.4 Ce(NO.sub.3).sub.3 7 11.9 43.2
82.0 2 Na.sub.2WO.sub.4 (NH.sub.4)Fe(SO.sub.4).sub.2 12 6.1 40.9
65.9 3 Na.sub.2WO.sub.4 NiSO.sub.4 7 5.7 47.7 81.4 4
Na.sub.2WO.sub.4 Co(OAc).sub.2 8 4.7 44.8 80.5 5
(NH.sub.4).sub.6Mo.sub.7O.sub.24 Ce(NO.sub.3).sub.3 13 11.9 65.0
92.9 6 (NH.sub.4).sub.6Mo.sub.7O.sub.24 CoSO4 7 6.3 30.2 98.1 7
MnSO.sub.4 (NH.sub.4)Fe(SO.sub.4).sub.2 24 5.9 80.0 73.7 8
MnSO.sub.4 NiSO.sub.4 9 8.6 40.4 24.3 9 MnSO.sub.4 Co(OAc).sub.2 15
4.9 87.6 70.7 10 MnSO.sub.4 Ce(NO.sub.3).sub.3 14 11.6 87.5 38.4 11
MnSO.sub.4 KMnO.sub.4 5 9.3 47.3 43.6 12 NH.sub.4H.sub.2PO.sub.4
CoSO.sub.4 7 4.8 40.3 55.8 CE-1 Na.sub.2WO.sub.4 None -- -- 35.0
55.7 CE-2 (NH.sub.4).sub.6Mo.sub.7O.sub.24 None -- -- 56.3 98.6
CE-3 MnSO.sub.4 None -- -- 21.6 27.3 CE-4 NH.sub.4H.sub.2PO.sub.4
None -- -- 19.4 15.4
TABLE-US-00002 TABLE 2 Conversion of BT and DBT in the reaction of
oxidation with hydrogen peroxide in the presence of exogenous
binary catalysts and acetic acid. Co-Catalyst Catalyst-Co-Catalyst
Conversion Percentage Example Catalyst Formula mg molar ratio DBT
DOS 13 MoO.sub.3 (NH.sub.4)Fe(SO.sub.4).sub.2 5 33.1 69.8 67.8 14
NH.sub.4H.sub.2PO.sub.4 CoSO.sub.4 5 13.5 87.9 17.2 15
NH.sub.4H.sub.2PO.sub.4 NiSO.sub.4 12 9.5 88.4 25.3 16
(NH.sub.4).sub.6Mo.sub.7O.sub.24 Ce(NO.sub.3).sub.3 13 11.9 48.5
54.4 CE-5 MoO.sub.3 None -- -- 13.9 16.2 CE-6
NH.sub.4H.sub.2PO.sub.4 None -- -- 10.8 8.0 CE-7
(NH.sub.4).sub.6Mo.sub.7O.sub.24 None -- -- 34.2 45.6
TABLE-US-00003 TABLE 3 Conversion of BT and DBT in the reaction of
the oxidation with hydrogen peroxide in the presence of binary
catalysts, an acid, and a phase transfer catalyst. Phase
Co-Catalyst transfer Conversion Percentage Example Catalyst Formula
mg Acid catalyst BT DBT DOS 17 (NH.sub.4).sub.6Mo.sub.7O.sub.24
KMnO.sub.4 5 Sulfuric Yes 69.8 67.8 100 18
(NH.sub.4).sub.6Mo.sub.7O.sub.24 KMnO.sub.4 5 Acetic Yes 87.9 17.2
100 19 (NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 6 Sulfuric Yes
83.0 99.7 100 20 (NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 6
Acetic Yes 81.0 99.8 100 21 (NH.sub.4)Fe(SO.sub.4).sub.2 CoSO.sub.4
9 Acetic Yes 88.4 25.3 87.5 CE-8 (NH.sub.4).sub.6Mo.sub.7O.sub.24
KMnO.sub.4 5 Sulfuric No 48.5 54.4 14.6 CE-9
(NH.sub.4).sub.6Mo.sub.7O.sub.24 KMnO.sub.4 5 Acetic No 16.0 4.4
8.3 CE-10 (NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 6 Sulfuric No
56.4 86.9 99.8 CE-11 (NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 6
Acetic No 30.0 50.1 99.7
[0035] Examples 1 to 21 demonstrate that the process disclosed
herein, generally affords satisfactory sulfur removal of greater
than about 85 percent. Further, catalyst activity appears to be
dependent on the molecular structure of the catalyst. On comparing
the conversion efficiency of catalysts in Tables 1 and 2, it can be
seen that the binary catalysts having the following combinations
Mo/Fe, P/Co, and P/Ni demonstrate good catalytic activity in the
presence of acetic acid, while binary catalysts having the
following combinations Mo/Ce, Mo/Ni, and Mn/Co demonstrate good
catalytic activity in the presence of sulfuric acid. Furthermore,
at least as seen in Examples 9 and 10 and Comparative examples CE-2
the use of binary catalysts significantly improves the conversion
of the most difficult to oxidize sulfur-containing compound BT from
about 56 percent in the absence of the catalyst to about 87 percent
in the presence of the catalyst. Also, as seen in Table 3, Examples
17 to 21, use of a phase transfer catalyst demonstrates significant
improvement in the conversion of all the sulfur compounds used to
prepare the model fuel mixtures.
Examples 22 to 26 and Comparative Examples CE-12 to CE-13
Effect Of Oxidative Desulfurization On A Sulfur-Containing
Distillate Fuel Oil
[0036] 25 ml of Saudi Crude atmospheric distillate fraction
600-700.degree. F. (315-370.degree. C.), containing 2.255 weight
percent sulfur, is first mixed with sulfuric or acetic acid and a
binary catalyst consisting of about 250 mg of the first component
and about 50 mg of the second component and placed into a reaction
flask. Hydrogen peroxide (30 weight percent) is then added
sequentially in three portions by 3 ml to the flask under stirring.
The reaction mixture is stirred for about 30 minutes. The mixture
is centrifuged and the oil layer is separated from the aqueous one.
The oil layer is washed with 10 ml of acetonitrile to remove
oxidized products. The oil layer is analyzed on the Spectro Phoenix
II XRF analyzer. The results are provided in Table 4 below. In
general, the oxidized sulfur compounds may be separated from the
crude oil containing reaction mixture (first oxidized mixture)
using any of the techniques disclosed herein as being effective for
that purpose.
TABLE-US-00004 TABLE 4 Sulfur removal from distillate fuel oil and
oil yield in the reaction of the oxidation with hydrogen peroxide
in the presence of binary catalyst, an acid, and a phase transfer
catalyst. Sulfur in Phase treated Sulfur Oil Co-Catalyst transfer
oil, removal, yield, Example Catalyst Formula mg Acid catalyst
perent percent percent 22 MnSO.sub.4 Co(OAc).sub.2 53 Sulfuric No
0.49 78.2 59.1 23 (NH.sub.4).sub.6Mo.sub.7O.sub.24
Ce(NO.sub.3).sub.3 51 Sulfuric No 0.40 82.3 83.5 24
(NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 52 Acetic No 1.47 34.8
86.0 25 (NH.sub.4).sub.6Mo.sub.7O.sub.24 MnSO.sub.4 52 Acetic Yes
1.29 42.8 84.0 CE-12 MnSO.sub.4 None -- Sulfuric No 1.03 54.3 85.1
CE-13 (NH.sub.4).sub.6Mo.sub.7O.sub.24 None -- Sulfuric No 0.41
81.8 50.4
[0037] Examples 22 to 25 also demonstrate that the process
disclosed herein, generally applicable to real oil distillates and
affords satisfactory sulfur removal of greater than about 80
percent at satisfactory fuel oil yield. On comparing the ODS
process efficiency of binary catalysts in examples 22 and 23 and
single component catalysts in comparative examples CE-12 and CE-13,
it can be seen that the binary catalyst having the combination
Mn/Co demonstrates noticeable improvement in sulfur removal, while
binary catalyst having the combination Mo/Ce demonstrates
significant improvement of the process selectivity and the fuel oil
yield. Furthermore, as seen in comparing Examples 24 and 25, the
use of a phase transfer catalyst significantly improves the sulfur
removal from a fuel oil at about the same oil yield in that is
obtained in the presence of acetic acid. It should be noted that
the experiments conducted as part of this study were not optimized
in all cases. Thus it is believed that much higher conversion of
sulfur compounds that those shown in Table 1, 2, 3 and 4 are
achievable, by adjusting various reaction parameters which are
known to those skilled in the art. Such optimization falls within
the scope of the instant invention.
[0038] In each of Examples 1 to 25 the oxidized sulfur compounds
may be separated from the reaction mixture (first oxidized mixture)
using any of the techniques disclosed herein as being effective for
that purpose. In one embodiment, the reaction mixture of Example 1
is filtered through a pad of silica gel to remove both the oxidized
sulfur compounds and the exogenous binary catalyst which may be
recovered therefrom.
[0039] The foregoing examples are merely illustrative, serving to
illustrate only some of the features of the invention. The appended
claims are intended to claim the invention as broadly as it has
been conceived and the examples herein presented are illustrative
of selected embodiments from a manifold of all possible
embodiments. Accordingly, it is Applicants' intention that the
appended claims are not to be limited by the choice of examples
utilized to illustrate features of the present invention. As used
in the claims, the word "comprises" and its grammatical variants
logically also subtend and include phrases of varying and differing
extent such as for example, but not limited thereto, "consisting
essentially of" and "consisting of." Where necessary, ranges have
been supplied, those ranges are inclusive of all sub-ranges there
between. It is to be expected that variations in these ranges will
suggest themselves to a practitioner having ordinary skill in the
art and where not already dedicated to the public, those variations
should where possible be construed to be covered by the appended
claims. It is also anticipated that advances in science and
technology will make equivalents and substitutions possible that
are not now contemplated by reason of the imprecision of language
and these variations should also be construed where possible to be
covered by the appended claims.
* * * * *