Process for Oxidative Desulfurization and Sulfone Disposal Using Solvent Deasphalting

• US 20120055843A1
• Filed: 09/07/2010
• Published: 03/08/2012
• Est. Priority Date: 09/07/2010
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Bourane, Abdennour, Koseoglu, Omer Refa, Kressmann, Stephane Cyrille
• Granted Patent: US 9,598,647 B2
• Time in Patent Office: Days
• US Class Current: 208/45
• CPC Class Codes: C10G 21/003 Solvent de-asphalting
• CPC Class Codes: C10G 21/06 characterised by the solvent used
• CPC Class Codes: C10G 21/12 Organic compounds only
• CPC Class Codes: C10G 21/16 Oxygen-containing compounds
• CPC Class Codes: C10G 21/22 Compounds containing sulfur, selenium, or tellurium
• CPC Class Codes: C10G 21/28 Recovery of used solvent
• CPC Class Codes: C10G 2300/202 Heteroatoms content, i.e. S, N, O, P
• CPC Class Codes: C10G 2300/206 Asphaltenes
• CPC Class Codes: C10G 2300/44 Solvents
• CPC Class Codes: C10G 25/003 Specific sorbent material, not covered by C10G25/02 or C10G25/03
• CPC Class Codes: C10G 27/04 with oxygen or compounds generating oxygen
• CPC Class Codes: C10G 27/12 with oxygen-generating compounds, e.g. per-compounds, chromic acid, chromates plumbites or plumbates C10G19/06
• CPC Class Codes: C10G 53/04 including at least one extraction step
• CPC Class Codes: C10G 53/08 including at least one sorption step
• CPC Class Codes: C10G 53/14 including at least one oxidation step

Abstract

A method and apparatus for upgrading a hydrocarbon feedstock is provided. The method includes the steps of (a) supplying a hydrocarbon feedstock to an oxidation reactor, wherein the hydrocarbon feedstock is oxidized in the presence of a catalyst under conditions sufficient to selectively oxidize sulfur compounds present in the hydrocarbon feedstock; (c) separating the hydrocarbons and the oxidized sulfur compounds by solvent extraction; (d) collecting a residue stream that includes the oxidized sulfur compounds; and (e) supplying the residue stream to a deasphalting unit.

Claims

1. A method of upgrading a hydrocarbon feedstock, the method comprising the steps of:

supplying the hydrocarbon feedstock to an oxidation reactor, the hydrocarbon feedstock comprising sulfur containing compounds;

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 compounds present in the hydrocarbon feedstock to produce an oxidized hydrocarbon stream that comprises hydrocarbons and oxidized sulfur containing compounds;

separating the hydrocarbons and the oxidized sulfur compounds in the oxidized hydrocarbon stream by solvent extraction with a polar solvent to produce an extracted hydrocarbon stream and a mixed stream, the mixed stream comprising the polar solvent and the oxidized sulfur containing compounds, wherein the extracted hydrocarbon stream has a lower concentration of sulfur than the hydrocarbon feedstock;

separating the mixed stream into a first recovered polar solvent stream and a first residue stream; and

supplying the first residue stream to a deasphalting unit to produce a deasphalted oil stream and a pitch stream, wherein said pitch stream includes a substantial portion of the oxidized sulfur containing compounds removed from the hydrocarbon feedstock.

2. The method of claim 1, wherein the oxidant is selected from the group consisting of air, oxygen, oxides of nitrogen, peroxides, hydroperoxidies, organic peracids, and combinations thereof.

3. The method of claim 1, wherein the catalyst is a metal oxide having the formula M_xO_y, wherein M is an element selected from Groups IVB, VB, and VIB of the periodic table.

4. The method of claim 1, wherein the oxidation reactor is maintained at a temperature of between about 20 and 150°

C. and at a pressure of between about 1-10 bars.

5. The method of claim 1, wherein the ratio of the oxidant to sulfur containing compounds present in the hydrocarbon feedstock is between about 4:

1 and 10;

1.

6. The method of claim 1, wherein the polar solvent has a Hildebrandt value of greater than about 19.

7. The method of claim 1, wherein the polar solvent is selected from the group consisting of acetone, carbon disulfide, pyridine, dimethyl sulfoxide, n-propanol, ethanol, n-butanol, propylene glycol, ethylene glycol, dimethlyformamide, acetonitrile, methanol and combinations of the same.

8. The method of claim 1, wherein the polar solvent is acetonitrile.

9. The method of claim 1, wherein the polar solvent is methanol.

10. The method of claim 1, wherein the solvent extraction is conducted at a temperature of between about 20°

C. and 60°

C. and at a pressure of between about 1-10 bars.

11. The method of claim 1, further comprising the step of supplying the extracted hydrocarbon stream to a stripper to produce a second recovered polar solvent stream and a stripped hydrocarbon stream.

12. The method of claim 1, further comprising the step of supplying the extracted hydrocarbon stream to an adsorption column, the adsorption column being charged with an adsorbent suitable for the removal of oxidized compounds present in the extracted hydrocarbon stream, the adsorption column producing a high purity hydrocarbon product stream and a second residue stream, the second residue stream containing a portion of the oxidized sulfur containing compounds and oxidized nitrogen containing compounds.

13. The method of claim 12, further comprising supplying the second residue stream to the deasphalting unit.

14. The method of claim 12, wherein the adsorbent is selected from the group consisting of activated carbon, silica gel, alumina, natural clays and combinations of the same.

15. The method of claim 12, wherein the adsorbent is a polymer coated support, wherein the support has a high surface area and is selected from the group consisting of silica gel, alumina, and activated carbon, and the polymer is selected from the group consisting of polysulfone, polyacrylonitrile, polystyrene, polyester terephthalate, polyurethane and combinations of the same.

16. The method of claim 1, wherein the step of supplying the first residue stream to the deasphalting unit further comprises supplying a deasphalting solvent selected from a paraffinic solvent having between 3 and 7 carbon atoms to the deasphalting unit and extracting the first residue stream with the deasphalting solvent at a temperature and pressure at or below the critical temperature and pressure of the paraffinic solvent, wherein the deasphalted oil stream includes a major fraction of the paraffinic solvent.

17. A method of upgrading a hydrocarbon feedstock, the method comprising the steps of:

supplying the hydrocarbon feedstock to an oxidation reactor, the hydrocarbon feedstock comprising sulfur containing compounds;

catalytically oxidizing the sulfur containing compounds in the hydrocarbon feedstock in the oxidation reactor with an oxidant in the presence of a catalyst under conditions sufficient to selectively oxidize the sulfur containing compounds present in the hydrocarbon feedstock to sulfones and produce a treated hydrocarbon stream comprising hydrocarbons and sulfones;

extracting the treated hydrocarbon stream with a polar organic solvent to produce an extracted hydrocarbon stream and a mixed stream, the mixed stream comprising the polar organic solvent and the sulfones, wherein the extracted hydrocarbon stream has a lower sulfur concentration than the hydrocarbon feedstock;

separating the mixed stream into a first recovered polar solvent stream and a first residue stream comprising sulfones;

supplying the extracted hydrocarbon stream to a stripper, the stripper operable to separate the extracted hydrocarbon stream into a stripped oil stream and a second recovered polar solvent stream;

supplying the first recovered polar solvent stream and second recovered polar solvent stream to the extraction step; and

supplying the residue stream comprising sulfones to a deasphalting unit and extracting the residue stream with a paraffinic solvent having between 3 and 7 carbon atoms to produce a deasphalted oil stream and a pitch stream, wherein said extraction of the residue stream is conducted a temperature and pressure that is at or below the supercritical temperature and pressure of the paraffinic solvent.

18. The method of claim 17 wherein the oxidation reactor is maintained at a temperature of between about 20 and 150°

C. and at a pressure of between about 1-10 bars and the solvent extraction is conducted at a temperature of between about 20°

C. and 60°

C. and at a pressure of between about 1-10 bars.

19. The method of claim 17 wherein the polar solvent has a Hildebrandt value of greater than about 19.

20. The method of claim 17 wherein the polar solvent is methanol.

21. The method of claim 17 wherein the polar solvent is acetonitrile.

22. The method of claim 17, further comprising the step of supplying the extracted hydrocarbon stream to an adsorption column, the adsorption column being charged with an adsorbent suitable for the removal of oxidized compounds present in the extracted hydrocarbon stream, the adsorption column producing a high purity hydrocarbon product stream and a second residue stream, the second residue stream containing a portion of the oxidized compounds.

23. The method of claim 17, further comprising supplying the second residue stream to the deasphalting unit.

24. An apparatus for upgrading a hydrocarbon feedstock comprising sulfur containing compounds, the apparatus comprising:

an oxidation vessel, said oxidation vessel comprising input lines for supplying the hydrocarbon feedstock, a catalyst, and an oxidant to the oxidation vessel, and an output line for withdrawing a treated hydrocarbon stream comprising oxidized sulfur containing compounds;

an extraction vessel for contacting the treated hydrocarbon stream comprising oxidized sulfur containing compounds with a solvent stream, said extraction vessel comprising inputs for supplying the treated hydrocarbon stream and the polar solvent, and further comprising outputs for removal of an extracted hydrocarbon stream and a mixed stream that includes the extraction solvent and oxidized sulfur compounds;

a distillation column for separating the mixed stream into a solvent recycle stream and a residue stream comprising oxidized sulfur compounds, the distillation column comprising an input for supplying the mixed stream and outputs for the removal of the solvent recycle stream and the residue stream; and

a solvent deasphalter, the solvent deasphalter comprising at least one input for receiving the residue stream, a paraffinic solvent, and a pitch stream, and an output for the removal of a deasphalted oil stream.