MEMBRANE DESULFURIZATION OF LIQUID HYDROCARBONS USING AN EXTRACTIVE LIQUID MEMBRANE CONTACTOR SYSTEM AND METHOD

• US 20110000823A1
• Filed: 06/29/2010
• Published: 01/06/2011
• Est. Priority Date: 07/01/2009
• Status: Abandoned Application

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Ramakrishna, Tammana Veera Venkata, Hamad, Esam Z., Hamad, Feras, Bahamdan, Ahmed, Yahaya, Garba O.
• Application Number:
  US12/826,019
• Publication Number:
  US 20110000823A1
• Time in Patent Office: Days
• US Class Current: 208/236
• CPC Class Codes: C10G 21/12 Organic compounds only
• CPC Class Codes: C10G 31/11 by dialysis

Abstract

The process of the present invention is directed to the desulfurization of a sulfur-containing hydrocarbon stream with a membrane contactor, where sulfur compounds are concentrated in a sulfur-rich stream on a permeate side of the membrane using an extractive liquid, and a sulfur-lean stream is recovered as a retentate. The sulfur-rich stream, which has a small volume relative to the original hydrocarbon stream, is conveyed to a recovery zone to recover extractive liquid, and the remaining hydrocarbon stream having an increased concentration of sulfur compounds is passed to a downstream desulfurization apparatus or system, such as a hydrotreating system, to recover the hydrocarbons associated with the organosulfur compounds.

Claims

1. A method of reducing the sulfur content of a sulfur-containing hydrocarbon feedstream comprising:

passing the feedstream in contact with a membrane on a retentate side of a membrane separation unit;

passing an extractive liquid in contact with the membrane on a permeate side of the membrane separation unit under conditions in which the extractive liquid contacts the feedstream;

concentrating sulfur compounds in the extractive liquid in a permeate stream of the membrane separation unit;

recovering as a retentate stream a first hydrocarbon product stream of reduced sulfur content;

recovering and subjecting the permeate stream to a fractionation process step for recovery of at least a portion of the extractive liquid; and

recovering a resulting sulfur-rich hydrocarbon stream from the fractionation process step.

2. The method of claim 1, wherein the sulfur-rich hydrocarbon stream is subjected to a hydrodesulfurization process step, and recovering a second hydrocarbon product stream of reduced sulfur content.

3. The method of claim 1, further comprising mixing the first and second hydrocarbon product streams to provide a final product stream of reduced sulfur content.

4. The method of claim 1, wherein the feedstream contains a plurality of different sulfur-containing compounds and at least certain of the sulfur-containing compounds are soluble in the extractive liquid.

5. The method of claim 4, wherein the extractive liquid is selected from the group consisting of fumaronitrile;

maleonitrile;

glyoxal;

2-nitrofuran;

acetonitrile;

acrylonitrile;

nitramine;

isoxazole;

furfural;

5-methylfurfural;

benzoylacetonitrile;

vinyl formate;

methyl formate;

oxazole;

sulfuric acid;

diketene;

benzonitrile;

acrolein;

dimethyl-oxalate;

furan;

benzaldehyde;

acetic anhydride;

methacrylonitrile;

dimethyl sulfide;

lactic acid;

acetic acid;

dimethyl formamide;

dimethyl sulfoxide;

aqueous potassium hydroxide;

furfuryl alcohol;

vinylacetylene;

nicotinonitrile;

pyridazine;

methylmaleic anhydride;

acetaldehyde;

cis-crotonitrie;

3-nitrobenzotrifluoride;

methyl phenyl ketone;

vinyl acetate;

p-tolualdehyde;

m-tolualdehyde;

o-tolualdehyde;

propylene-carbonate;

methanol;

methanol and aqueous sodium hydroxide;

dimethylsulfoxide and methanol;

1-ethyl, 3-methylimidazolium ethyl sulfate;

1-ethyl, 3-methylimidazolium methyl sulfate;

1-ethyl, 3-methylimidazolium hexafluorophosphate;

1-butyl, 3-methylimidazolium tetrafluoroborate;

1-ethyl, 3-methylimidazolium bis(trifluoromethanesulfonyl)imidate;

1-n-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate;

1-n-butyl-3-methylimidazolium;

1-n-butyl-3-methylimidazolium trifluorotris(pentafluoroethyl)phosphate;

1-n-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate; and

1-n-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate.

6. The method of claim 1, wherein target sulfur compounds comprise aliphatic sulfur molecules, and the extractive liquid is selected from the group consisting of acetonitrile;

dimethyl sulfoxide;

acrylonitrile;

benzonitrile;

dimethyl formamide;

aqueous sodium hydroxide;

aqueous potassium hydroxide;

furfuryl alcohol;

vinylacetylene;

sulfuric acid;

dimethylsulfoxide and methanol;

furfural; and

5-methylfurfural.

7. The method of claim 1, wherein target sulfur compounds comprise aromatic sulfur compounds including thiophenes, benzothiophenes and dibenzothiophenes, and the extractive liquid is selected from the group consisting of acetonitrile;

furfural;

benzonitrile;

dimethyl sulfide;

dimethyl formamide;

methanol;

lactic acid;

propylene-carbonate;

5-methylfurfural;

methyl formate;

1-ethyl, 3-methylimidazolium ethyl sulfate;

1-ethyl, 3-methylimidazolium methyl sulfate;

1-ethyl, 3-methylimidazolium hexafluorophosphate;

1-butyl, 3-methylimidazolium tetrafluoroborate;

1-ethyl, 3-methylimidazolium bis(trifluoromethanesulfonyl)imidate;

1-n-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate;

1-n-butyl-3-methylimidazolium trifluorotris(pentafluoroethyl)phosphate; and

1-n-butyl-3-methylimidazolium.

8. The method of claim 1, wherein target sulfur compounds comprise alkyl derivatives of aromatic sulfur molecules including 4,6-dimethyl-dibenzothiophenes, and the extractive liquid is selected from the group consisting of acetonitrile;

acrylonitrile;

furfural;

5-methylfurfural;

benzoylacetonitrile;

vinyl formate;

diketene;

benzonitrile;

acrolein;

dimethyl-oxalate;

benzaldehyde;

acetic anhydride;

methacrylonitrile;

acetic acid;

dimethyl formamide;

dimethyl sulfoxide;

aqueous potassium hydroxide;

furfuryl alcohol;

1-ethyl, 3-methylimidazolium ethyl sulfate;

1-ethyl, 3-methylimidazolium methyl sulfate;

1-ethyl, 3-methylimidazolium hexafluorophosphate;

1-butyl, 3-methylimidazolium tetrafluoroborate; and

1-ethyl, 3-methylimidazolium bis(trifluoromethanesulfonyl)imidate.

9. The method of claim 1, wherein the membrane is a porous membrane.

10. The method of claim 9, wherein the porous membrane constitutes a controlled interface for contact between the hydrocarbon feedstream and the extractive liquid.

11. The method of claim 9, wherein the porous membrane constitutes a non-dispersive contact interface between the extractive liquid and the hydrocarbon feedstream.

12. The method of claim 9, wherein the porous membrane comprises a material which is insoluble in the hydrocarbon and the extractive liquid.

13. The method of claim 9, wherein the porous membrane comprises a material which undergoes minimal swelling in the hydrocarbon and the extractive liquid.

14. A liquid hydrocarbon desulfurization system comprising:

a source of extractive liquid;

a membrane housing including

a porous membrane having a retentate side and a permeate side,

a retentate portion configured and dimensioned for maximizing contact between a liquid hydrocarbon feedstream and the retentate side of the membrane, and

a permeate portion configured and dimensioned for maximizing contact between the extractive liquid and the retentate side of the membrane.