Process for reducing the sulfur content from oxidized sulfur-containing hydrocarbons

Abstract

A process and system for reducing the sulfur content from a mixture of hydrocarbons and oxidized sulfur-containing hydrocarbons is provided by electrochemical decomposition. The electrochemical reactions occur under electrical potential and in the presence of an electrolyte solution that is effective promote decomposition of a portion of the oxidized sulfur compounds, to recover a hydrocarbon product having a reduced sulfur content while minimizing loss of hydrocarbon.

Claims

1. A process for reducing the sulfur content from an oxidation reactor effluent including a mixture of liquid hydrocarbons and oxidized sulfur-containing hydrocarbon compounds, the process comprising: electrochemically reacting the oxidation reactor effluent in an electrochemical reactor in the presence of an effective amount of electrolyte solution, the electrochemical reaction occurring under an electrical potential effective to promote decomposition of at least a portion of the oxidized sulfur-containing hydrocarbon compounds into a mixture of sulfur-free hydrocarbons and sulfur byproducts, mixing the mixture of sulfur-free hydrocarbons and sulfur byproducts with water; and separating the mixture of sulfur-free hydrocarbons and sulfur byproducts into sulfur-free hydrocarbons and a water/salt stream containing sulfur byproduct, wherein the electrochemical reaction occurs at a temperature from about 20 C. to about 350 C., at a pressure of about 3 kg/cm.sup.2 to about 30 kg/cm.sup.2, and at a liquid hourly space velocity of about 0.05 h.sup.1 to about 4.0 h.sup.1, wherein the electrolyte solution comprises an electrolyte salt in an organic solvent, and wherein the organic solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, nitrobenzene, benzonitrile, N-formyl morpholine, sulfolane and mixtures including at least one of the foregoing solvents.

2. The process according to claim 1 wherein the mixture of sulfur-free hydrocarbons and sulfur byproducts further comprises electrolyte and wherein the water/salt stream further contains electrolyte.

3. The process according to claim 1, wherein the overall cell potential of the electrochemical reactor is generally about 1.0 to about 2.5 V as measured against an Ag/AgCl reference electrode.

4. The process according to claim 3, wherein the electrochemical reactor comprises cathode(s) formed of a material selected from the group consisting of platinum, stainless steel and graphite and anode(s) formed of a material selected from the group consisting of platinum, stainless steel, nickel and graphite.

5. The process according to claim 1 wherein the electrolyte salt is a tetraalkylammonium salt.

6. The process according to claim 5 wherein the tetraalkylammonium salt is selected from the group consisting of tetra-ethylammonium perchlorate, tetrabutylammonium perchlorate, tetraethyl-ammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethyl-ammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, tetraethylammonium paratoluene sulfonate, tetrabutylammonium chloride, tetrabutylammonium bromide and mixtures including at least one of the foregoing salts.

7. The process according to claim 5 wherein the tetraalkylammonium salt is present in the organic solvent in a concentration of at least about 0.05 molar.

8. The process according to claim 5 wherein the tetraalkylammonium salt is present in the organic solvent in a concentration of at least about 0.1 molar.

9. The process according to claim 5 wherein the tetraalkylammonium salt is present in the organic solvent in a concentration of at least about 0.5 molar.

10. The process as in claim 1, wherein the oxidized sulfur-containing hydrocarbon compounds include sulfones and/or sulfoxides.

11. The process according to claim 1, wherein the oxidized sulfur-containing hydrocarbon compounds is derived from a gasoline, diesel fuel, or kerosene fraction.

12. The process according to claim 1, wherein the oxidized sulfur-containing hydrocarbon compounds include DBT sulfone and one or more alkyl substituted DBT sulfones selected from 4-MDBT sulfone, 4,6-DMDBT sulfone, 1,4-DMDBT sulfone, 1,3-DMDBT sulfone, TriMDBT sulfone, TriEDBT sulfone, or C3DBT sulfone.

13. The process according to claim 1, wherein the oxidation reactor effluent is from an oxidation process of a feedstock derived from naturally occurring fossil fuels such as crude oil, shale oils, coal liquids, intermediate refinery products or their distillation fractions such as naphtha, gas oil, vacuum gas oil or vacuum residue or combination thereof.

14. The process according to claim 1, wherein the oxidation reactor effluent is from an oxidation process of a hydrodesulfurization zone effluent boiling above a cut point in the range of from 320-360 C.

15. A process for desulfurization of a hydrocarbon feedstock comprising: a. supplying a hydrocarbon feedstock to an oxidation reactor, the hydrocarbon feedstock comprising a mixture of hydrocarbon compounds and a mixture of sulfur-containing hydrocarbon compounds; b. contacting the hydrocarbon feedstock with an oxidant in the presence of a catalyst in the oxidation reactor under conditions sufficient to selectively oxidize sulfur-containing hydrocarbon compounds present in the hydrocarbon feedstock to produce an oxidation reactor effluent including the mixture of hydrocarbon compounds and a mixture of oxidized sulfur-containing hydrocarbon compounds; c. passing the oxidation reactor effluent to an extraction zone for contacted with an extraction solvent to produce a desulfurized hydrocarbon product stream and an oxidized sulfur-containing hydrocarbon stream; d. electrochemically reacting the oxidized sulfur-containing hydrocarbon stream in an electrochemical reactor in the presence of an effective amount electrolyte solution, the electrochemical reaction occurring under an electrical potential effective to promote decomposition of at least a portion of the oxidized sulfur-containing hydrocarbon compounds into a desulfurized effluent containing a mixture of sulfur-free hydrocarbons and sulfur byproduct, wherein the electrochemical reaction occurs at a temperature from about 20 C. to about 350 C., at a pressure of about 3 kg/cm.sup.2 to about 30 kg/cm.sup.2, and at a liquid hourly space velocity of about 0.05 h.sup.1 to about 4.0 h.sup.1, and wherein the electrolyte solution comprises an electrolyte salt in an organic solvent, and wherein the organic solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, nitrobenzene, benzonitrile, N-formyl morpholine, sulfolane and mixtures including at least one of the foregoing solvents; e. mixing the desulfurized effluent with water; and f. separating the mixture water and desulfurized effluent into sulfur-free hydrocarbons and a water/salt stream containing sulfur byproduct.

16. The process as in claim 15, wherein the oxidized sulfur-containing hydrocarbon compounds include sulfones and/or sulfoxides.

17. The process according to claim 15, wherein the hydrocarbon feedstock is a gasoline, diesel fuel, or kerosene fraction.

18. The process according to claim 15, wherein the oxidized sulfur-containing hydrocarbon compounds include DBT sulfone and one or more alkyl substituted DBT sulfones selected from 4-MDBT sulfone, 4,6-DMDBT sulfone, 1,4-DMDBT sulfone, 1,3-DMDBT sulfone, TriMDBT sulfone, TriEDBT sulfone, or C3DBT sulfone.

19. The process according to claim 15, wherein the hydrocarbon feedstock is derived from naturally occurring fossil fuels such as crude oil, shale oils, coal liquids, intermediate refinery products or their distillation fractions such as naphtha, gas oil, vacuum gas oil or vacuum residue or combination thereof.

20. The process according to claim 15, wherein the hydrocarbon feedstock is a fraction of an oxidized effluent from a hydrodesulfurization zone boiling above a cut point in the range of from 320-360 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing summary as well as the following detailed description of preferred embodiments of the invention will be best understood when read in conjunction with the attached drawings. For the purpose of illustrating the invention, there are shown in the embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and apparatus shown. In the drawings the same or similar reference numerals are used to refer to the same or similar elements, in which:

(2) FIG. 1 is a schematic process flow diagram of an integrated desulfurization system and process for removal of oxidized sulfur-containing hydrocarbon compounds formed by oxidative desulfurization; and

(3) FIG. 2 is a schematic process flow diagram of another embodiment of an integrated desulfurization system and process for removal of oxidized sulfur-containing hydrocarbon compounds formed by oxidative desulfurization.

DETAILED DESCRIPTION OF THE INVENTION

(4) The present process is concerned with reducing the concentration of oxidized sulfur-containing hydrocarbon compounds from a mixture of liquid hydrocarbons and oxidized sulfur-containing hydrocarbon, typically resulting from oxidative desulfurization of liquid hydrocarbons. In general, the oxidized sulfur-containing hydrocarbon are admixed with an electrolyte composition and subjected to an applied electric potential and under conditions effective to decompose intermediate products from an oxidative desulfurization process.

(5) FIG. 1 is a schematic process flow diagram of an integrated system 8 for carrying out oxidative desulfurization of a hydrocarbon feed and electrochemical decomposition of the oxidized sulfur-containing hydrocarbon intermediate products, including sulfones. Apparatus 8 generally includes an oxidative desulfurization zone 10 to convert sulfur-containing hydrocarbons to oxidized sulfur-containing hydrocarbons, an electrochemical reaction zone 40 to decompose oxidized sulfur-containing hydrocarbons, and a separation zone 60 for recovery of hydrocarbon product and removal of electrolyte and sulfur compounds derived from the oxidized sulfur-containing hydrocarbons.

(6) Oxidative desulfurization zone 10 generally includes a feed inlet for receiving a hydrocarbon feed 12 to be desulfurized, one or more inlets for receiving an oxidizing agent 14 and an oxidizing catalyst 16, and an oxidized effluent outlet for discharging the mixture 18 of desulfurized hydrocarbons and oxidized sulfur-containing hydrocarbon compounds. Note that while separate streams are shown for the oxidant and catalyst that are introduced to the oxidative desulfurization zone 10, a person having ordinary skill in the art will appreciate that these can be combined as a single stream to the oxidative desulfurization zone 10 and/or combined with the feed 12 prior to introduction into the oxidative desulfurization zone 10.

(7) The electrochemical reaction zone 40 generally includes an inlet in fluid communication with the source of a mixture 34 of the oxidized sulfur-containing hydrocarbons 18 (directly or after an optional intermediate step to recover desulfurized hydrocarbons described further herein) and electrolyte solution 36, and an outlet for discharging an intermediate hydrocarbon mixture 46 containing desulfurized hydrocarbons, electrolyte and sulfur compounds.

(8) Separation zone 60 generally includes an inlet in fluid communication with electrochemical reaction zone 40 to receive intermediate hydrocarbon products 46, an outlet for discharging a mixture 54 of electrolyte solution and sulfur byproducts, and an outlet for recovering the desulfurized hydrocarbon product 52. In certain embodiments electrolyte solution can be recycled from stream 54 after removal of water and sulfur byproducts (not shown).

(9) In an integrated process carried out using system 8 described with respect to FIG. 1, a hydrocarbon feedstock 12, along with effective quantities of oxidizing agent and oxidizing catalyst, is introduced to the oxidative desulfurization zone 10 operating under conditions which facilitate oxidative desulfurization reactions, i.e., conversion of sulfur-containing hydrocarbon compounds into their respective oxides, including sulfones and sulfoxides. In certain embodiments the oxidizing agent, oxidizing catalyst and/or operating conditions are tailored to promote sulfone formation.

(10) The effluent of oxidative desulfurization zone 10, mixture 18 containing desulfurized hydrocarbons and oxidized sulfur-containing hydrocarbon compounds, is discharged and combined with an electrolyte solution 36 conveyed, and the resulting mixture 34 is conveyed to the electrochemical reaction zone 40. In certain embodiments, the mixture 18 can be subjected to extraction in an extractor 20 to recover desulfurized hydrocarbon products 26 and concentrate the oxidized sulfur-containing hydrocarbon compounds in a stream 22, which is mixed with the electrolyte solution 36.

(11) The hydrocarbon stream that is subjected to oxidative desulfurization can be derived from naturally occurring fossil fuels such as crude oil, shale oils, coal liquids, intermediate refinery products or their distillation fractions such as naphtha, gas oil, vacuum gas oil or vacuum residue or combination thereof. A suitable feedstock can be characterized by a boiling point within the range of about 150 C. to about 1500 C., although one of ordinary skill in the art will appreciated that certain other hydrocarbon streams can benefit from the practice of the system and method described herein.

(12) The hydrocarbon feedstream subjected to oxidation in oxidative desulfurization zone can also be an effluent from a hydrodesulfurization zone. In such case, the oxidized effluent from the oxidative desulfurization zone can be fractioned to remove the portion not containing oxidation products, e.g., a fraction boiling below cut point in the range of about 320-360 C., thereby reducing the requisite flow capacity of the electrochemical reactor. In such systems, the feed can be contacted with a hydrodesulfurization catalyst in a hydrodesulfurization reaction zone, for instance, under mild conditions (e.g., 20-40 kg/cm.sup.2 hydrogen partial pressure, 300-360 C. and a liquid hourly space velocity of 1-8 h.sup.1) to reduce the sulfur level to a relatively low level (e.g., 500-3000 ppmw). The hydrotreated feedstock is then contacted with an oxidizing agent and a catalyst in the oxidation reaction zone under mild conditions to convert the sulfur-containing hydrocarbons into their oxidation products.

(13) The oxidizing agent for use during oxidative desulfurization can be selected from liquid hydrogen peroxide and organic peroxides selected from the group consisting of alkyl or aryl hydroperoxides and dialkyl and diaryl peroxides, wherein the alkyl and aryl groups of the respective dialkyl and diaryl peroxides are the same or different. An effective quantity of oxidizing agent is used, which varies with the selected compound(s). For instance, a molar ratio of hydrogen peroxide-to-sulfur is typically at least 4:1 to effectively oxidize organosulfur compounds into their respective oxidized sulfur compounds. In certain embodiment, the quantity of oxidizing agent is selected so that the respective oxidized sulfur compounds are primarily sulfones. Gaseous oxidants, such as air, oxygen, or nitrous oxide can also be used in certain embodiments.

(14) The oxidation catalysts can be homogeneous transition metal catalysts, active species of Mo(VI), W(VI), V(V), Ti(IV), or a combination thereof possessing high Lewis acidity with weak oxidation potential. For homogeneous catalysts, metal salts are dissolved in aqueous solutions and added to the reactant mixture in solution as catalyst.

(15) In embodiments using liquid oxidants, the oxidative desulfurization zone 10 can operate at atmospheric pressure, and at a temperature in the range of from about 80-140 C. and in certain embodiments 80-100 C. In embodiments using gaseous oxidant the oxidative desulfurization zone 10 can operate at a pressure range of from about 10-100 kg/cm.sup.2, in certain embodiments of from about 10-50 kg/cm.sup.2 and in further embodiments of from about 10-30 kg/cm.sup.2, and a temperature in the range of from about 250-350 C.

(16) The electrochemical reactor 40 can be in any suitable configuration that promotes for electrochemical decomposition of oxidized sulfur-containing hydrocarbons. For instance, FIG. 1 shows a schematic of an electrochemical reactor 40 which includes an anode 42 and one or more cathodes 44 to which are applied a source of DC current (not shown). The design of the reactor vessel 40 and the electrodes 42, 44 provide for intimate contact between the moving solution from stream 34, containing the oxidized sulfur-containing hydrocarbons and the electrolyte solution, and the electrode surface, so as to promote the reactions that lead to decomposition of the oxidized sulfur-containing hydrocarbons into sulfur-free hydrocarbons and sulfur byproducts. While not wishing to be bound by theory, it is believed that the sulfur compounds in the oxidized sulfur-containing hydrocarbons form salts that are removed in the separation zone 60.

(17) In general, the cathode(s) 44 of the electrochemical cell reactor 40 are formed of a material selected from the group consisting of platinum, stainless steel and graphite. Anode(s) 42 of the electrochemical cell reactor 40 are formed of a suitable material selected from the group consisting of platinum, stainless steel, nickel and graphite. The cathode and anode are connected to a suitable voltage source that applies a current across the electrodes. The overall cell potential of the electrochemical reactor can be about 1.0 to about 2.5 V (measured against an Ag/AgCl reference electrode.)

(18) The electrochemical reactor can operate at a reaction temperature of from about 20 C. to about 350 C., a reaction pressure of from about 3 kg/cm.sup.2 to about 30 kg/cm.sup.2, and a liquid hourly space velocity of from about 0.05 h.sup.1 to about 4.0 h.sup.1.

(19) The oxidized sulfur-containing hydrocarbons are converted in the electrochemical reactor, under the applied electric potential and in the presence of an electrolyte solution including electrolyte and solvent, into desulfurized hydrocarbons and sulfur compounds that are in an aqueous phase and removed in the separation zone 60. Organic solvents effective for the process herein can be selected from the group consisting of ethylene carbonate, propylene carbonate, nitrobenzene, benzonitrile, N-formyl morpholine, sulfolane and mixtures including at least one of the foregoing solvents. Solvents vary by chemical type, polarity, efficacy and stability, and persons of ordinary skill in the art can readily establish the useful and effective ratios of solvent for a given feedstream and sulfur speciation.

(20) Suitable electrolytes effective for the process herein include tetraalkylammonium salts selected from the group consisting of such as tetra-ethylammonium perchlorate, tetrabutylammonium perchlorate, tetraethyl-ammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethyl-ammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, tetraethylammonium paratoluene sulfonate, tetrabutylammonium chloride, tetrabutylammonium bromide and mixtures including at least one of the foregoing salts. These electrolytes are present in an effective concentration, which can be measured based on the solubility of the selected electrolyte in the selected solvent. In general, the electrolytes are soluble in the organic solvent to a concentration of at least about 0.05 molar, in certain embodiments at least about 0.1 molar and in further embodiments at least about 0.5 molar.

(21) There is no catalyst required for the electrochemical decomposition reactions of oxides of sulfur compounds.

(22) The electrochemical reaction effluents 46 are separated in the separation zone 60. Water 62 is added to the reaction effluent to remove the sulfur compounds and electrolyte components in salt form. Separation zone 60 generally operations as a phase separator in which an aqueous phase 54 includes electrolyte salts and decomposed sulfur byproducts, and an oil phase 52 includes the desulfurized hydrocarbon product and a minor amount of the solvent or electrolyte solution.

(23) FIG. 2 shows a process similar to that of FIG. 1 with an extraction zone 120 for recovery of desulfurized product prior to electrochemical reaction for sulfone decomposition, and a separation zone 130 for removal of aqueous salt solutions derived from a homogeneous catalyst used in aqueous phase in the oxidative desulfurization process. In an integrated process carried out using system 108 shown with respect to FIG. 2, a hydrocarbon feedstock 112, along with effective quantities of oxidizing agent 114 and aqueous phase homogeneous oxidizing catalyst 116, is introduced to the oxidative desulfurization zone 110. The effluent of oxidative desulfurization zone 110, mixture 132 containing desulfurized hydrocarbons, oxidized sulfur-containing hydrocarbon compounds and an aqueous phase, is passed to a separator 130 for removal of an aqueous phase 134 and recovery of a non-aqueous oil phase 118, a mixture containing desulfurized hydrocarbons and oxidized sulfur-containing hydrocarbon compounds.

(24) The non-aqueous oxidized effluent 118 is supplied to the extraction vessel 120 where it is contacted with a stream of recycled extraction solvent 174 and make-up extraction solvent 172. The extraction solvent can be a polar solvent, and in certain embodiments, can have a Hildebrandt solubility value of greater than about 19. In certain embodiments, when selecting the particular polar solvent for use in extracting oxidized sulfur and nitrogen containing species, selection may be based upon, in part, solvent density, boiling point, freezing point, viscosity, and surface tension. Exemplary polar solvents suitable for use in the extraction step can include acetone (Hildebrand value of 19.7), carbon disulfide (20.5), pyridine (21.7), dimethyl sulfoxide (DMSO) (26.4), n-propanol (24.9), ethanol (26.2), n-butyl alcohol (28.7), propylene glycol (30.7), ethylene glycol (34.9), dimethylformamide (DMF) (24.7), acetonitrile (30), methanol (29.7), and the like. In certain embodiments, acetonitrile and methanol, due to their low cost, volatility, and polarity, are preferred. In certain embodiments, solvents that include sulfur, nitrogen, or phosphorous, preferably have a relatively high volatility to ensure adequate stripping of the solvent from the hydrocarbon feedstock. Extraction zone 120 can be operated at a temperature of between about 20 C. and 60 C., in certain embodiments between about 25 C. and 45 C., and in further embodiments between about 25 C. and 35 C. Extraction zone 120 can operate at a pressure of between about 1 and 10 bars, in certain embodiments between about 1 and 5 bars, and in further embodiments between about 1 and 2 bars. In certain embodiments, extraction zone 120 operates at a pressure of between about 2 and 6 bars. The ratio of the extraction solvent to non-aqueous oxidized effluent 118 can be between about 1:3 and 3:1, in certain embodiments between about 1:2 and 2:1, and in further embodiments about 1:1. Contact time between the extraction solvent and non-aqueous oxidized effluent 118 can be between about 1 second and 60 minutes, in certain embodiments less than about 15 minutes. In certain embodiments, extraction zone 120 can include various means for increasing the contact time between the extraction solvent and the non-aqueous oxidized effluent 118, or for increasing the degree of mixing of the two solvents. Means for mixing can include mechanical stirrers, agitators, trays, or like means.

(25) A desulfurized hydrocarbon product 126 and a stream of sulfones and sulfoxides 122 are produced from the extraction zone 120. While the desulfurized hydrocarbon product 126 is recovered the sulfones and sulfoxides stream 122 is admixed with electrolyte solution 136 and the mixture is conveyed to the electrochemical reaction zone 140. As described with respect to FIG. 1 oxidized sulfur-containing hydrocarbons are converted in the electrochemical reactor, under the applied electric potential and in the presence of an electrolyte solution including electrolyte and solvent, into desulfurized hydrocarbons and sulfur compounds that are in an aqueous phase.

(26) Upon completion of sulfone decomposition in electrochemical reaction zone 140, a desulfurized effluent 146 exits therefrom and is mixed with water stream 162 and sent to the separation zone 160 to remove reaction by-products with a stream of salt, resulting in a water/salt stream 154 including electrolyte and sulfur byproducts. A stream of recovered desulfurized hydrocarbons 152 is recovered.

(27) In further embodiments, an adsorption zone (not shown) can be incorporated in fluid communication with the desulfurized hydrocarbon 126 and/or 152 for further desulfurization. Exemplary adsorbents can include activated carbon, silica gel, alumina, natural clays and other inorganic adsorbents. It can also include polar polymers that have been applied to silica gel, activated carbon and alumina. The adsorption zone can be a column operated at effective temperature and pressure ranges, and adsorbent to oil ratios, to achieve the desired degree of final desulfurization.

(28) Accordingly, a system and process is described herein which is capable of efficiently and cost-effectively reducing the sulfur content of hydrocarbon fuels while minimizing loss of hydrocarbons. Deep desulfurization of hydrocarbon fuels according to the present process effectively optimizes use of integrated apparatus and processes, combining oxidative desulfurization and sulfone electrochemical decomposition. Using the system and process of the present invention, refiners can incorporate oxidative desulfurization into sulfur removal schemes, and existing hydrodesulfurization equipment can be used and run under relatively mild operating conditions. Accordingly hydrocarbon fuels can be economically desulfurized to an ultra-low level and hydrocarbon product recovery can be maximized since a portion of organosulfur compounds are converted to sulfur-free hydrocarbons and separable sulfur byproducts.

EXAMPLE

(29) A hydrotreated straight run diesel containing 500 ppmw of elemental sulfur 0.28 W % of organic sulfur density of 0.85 Kg/L was subjected to oxidative desulfurization under the following reaction conditions: oxidant (Hydrogen peroxide) to sulfur molar ration of 4:1; Mo(IV) oxidation catalyst; a reaction time of 30 minutes; and reaction temperature of 80 C.; and a reaction pressure of 1 Kg/cm.sup.2.

(30) The below mass balance tables show reference number streams corresponding with the schematic process flow diagram in FIG. 2, and do not include the non-reactive components to the electrochemical reaction zone, electrolyte and solvent.

(31) TABLE-US-00002 TABLE 2 Oxidative Desulfurization Diesel Stream Name Diesel Oxidant Catalyst Catalyst Oxidized Stream Type Feed Oxidant Catalyst Waste Product Stream Unit 112 114 116 134 118 Phase Oil Aqueous Aqueous Aqueous Oil Diesel Kg 1000 3 995 Diesel Reject Kg Acetic Acid Kg 0 136 34 86 H.sub.2O.sub.2 Kg 2 0 H.sub.2O Kg 0 4 4 3 0 Na.sub.2WO.sub.4 Kg 1 1 1 Total Kg 1000 6 141 41 1082

(32) TABLE-US-00003 TABLE 3 Extraction Diesel Desulfurized Stream Name Oxidized CH3OH Oil Sulfones Stream Type Feed Solvent Product Product Stream Unit 118 172 126 122 Phase Oil Solvent Oil Oil Diesel Kg 995 879 Diesel Reject Kg 93 Acetic Acid Kg 86 H.sub.2O.sub.2 Kg H.sub.2O Kg 0 0 Na.sub.2WO.sub.4 Kg Methanol Kg 1082 7 Total Kg 1082 1082 886 93

(33) TABLE-US-00004 TABLE 4 Sulfone Decomposition Recovered Stream Name Sulfones Hydrocarbons Stream Type Feed Product Stream Unit 122 152 Phase Oil Sulfones Kg 93 Recovered Kg 87 Hydrocarbons Total Kg 93 87

(34) The method and system of the present invention have been described above and in the attached drawings; however, modifications will be apparent to those of ordinary skill in the art and the scope of protection for the invention is to be defined by the claims that follow.