HYDROGEN RECYCLE AND HYDROGEN CLORIDE RECOVERY IN AN ALKYLATION PROCESS

• US 20140039231A1
• Filed: 07/31/2012
• Published: 02/06/2014
• Est. Priority Date: 07/31/2012
• Status: Active Grant

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Timken, Hye Kyung Cho, Cleverdon, Robert Fletcher, Chang, Bong-Kyu, Phillips, Christine Marie, Mohr, Donald Henry
• Granted Patent: US 9,233,316 B2
• Time in Patent Office: Days
• US Class Current: 585/251
• CPC Class Codes: B01D 3/009 in combination with chemical reactions
• CPC Class Codes: B01J 2231/32 Addition reactions to C=C or C-C triple bonds
• CPC Class Codes: B01J 31/0277 comprising ionic liquids, as components in catalyst systems or catalysts per se, the ionic liquid compounds being used in the molten state at the respective reaction temperature
• CPC Class Codes: B01J 31/0281 the nitrogen being a ring member
• CPC Class Codes: C07C 2/58 Catalytic processes
• CPC Class Codes: C07C 5/02 by hydrogenation simultaneous hydrogenation and dehydrogenation C07C5/52
• CPC Class Codes: C10G 29/205 by reaction with hydrocarbons added to the hydrocarbon oil
• CPC Class Codes: Y02P 20/584 Recycling of catalysts

Abstract

We provide an alkylation process, comprising: separating and recycling a hydrogen gas and a hydrogen chloride from an offgas of a hydrogenation reactor; wherein the hydrogen gas is recycled to the hydrogenation reactor; and wherein the hydrogen chloride is recycled to an alkylation reactor. We also provide an alkylation process unit for performing this process.

Claims

1. An alkylation process, comprising:

alkylating reactants in an alkylation reactor (300);

separating and recycling a hydrogen gas and a hydrogen chloride from an offgas (50) of a hydrogenation reactor (100);

wherein the hydrogen gas is recycled to the hydrogenation reactor (100); and

wherein the hydrogen chloride is recycled to the alkylation reactor (300).

2. The alkylation process of claim 1, wherein the hydrogen chloride is extracted from the offgas (50) of the hydrogenation reactor (100) using a hydrocarbon extraction solvent (25).

3. The alkylation process of claim 2, wherein the hydrocarbon extraction solvent (25) comprises an isomerized olefin.

4. The alkylation process of claim 1, wherein the alkylation reactor (300) uses an alkylation catalyst comprising a chloride.

5. The alkylation process of claim 4, wherein the alkylation catalyst is an ionic liquid catalyst.

6. The alkylation process of claim 5, wherein a hydrocarbon extraction solvent (25) is fed into a stream selected from the group consisting of a hydrogenated effluent (10), the offgas (50) of the hydrogenation reactor (100) that was separated in a separator (400), and a combination thereof.

7. The alkylation process of claim 6, wherein the hydrocarbon extraction solvent (25) is fed at a vol/vol ratio of the hydrocarbon extraction solvent (25) to the ionic liquid catalyst from 1.0 to 100.

8. The alkylation process of claim 6, wherein a vol/vol ratio of the hydrocarbon extraction solvent (25) to the ionic liquid catalyst is selected to provide a level of hydrogen chloride less than 600 wppm in a gas fraction comprising the hydrogen (20).

9. The alkylation process of claim 6, wherein a vol/vol ratio of the hydrocarbon extraction solvent (25) to the ionic liquid catalyst is selected to provide at least 85 wt % of the hydrogen chloride produced in the hydrogenation reactor (100), which is recovered and recycled to the alkylation reactor (300).

10. The alkylation process of claim 1, wherein the hydrogenation reactor (100) is used to regenerate a used alkylation catalyst.

11. The alkylation process of claim 1, wherein the separating is done in a fractionation unit (200) that is a distillation column.

12. The alkylation process of claim 1, wherein a hydrocarbon extraction solvent (25) is fed into a fractionation unit (200), used for the separating, at a location above where the offgas (50) of the hydrogenation reactor (100) is fed into the fractionation unit (200).

13. The alkylation process of claim 12, wherein the hydrocarbon extraction solvent (25) comprises an olefin and an isoparaffin to be alkylated to make an alkylate gasoline blending component.

14. The alkylation process of claim 13, wherein the olefin contains greater than 10 wt % 2-butene and the isoparaffin is isobutane.

15. The alkylation process of claim 1, additionally comprising separating an extracted conjunct polymer naphtha (45) from the effluent (10) of the hydrogenation reactor (100) and blending the extracted conjunct polymer naphtha (45) into an alkylate gasoline.

16. An alkylation process unit, comprising:

a. a fractionation unit (200) for separating a hydrogen gas and a hydrogen chloride from an offgas (50) of a hydrogenation reactor (100) that regenerates a used ionic liquid catalyst; and

b. a first connection between the fractionation unit (200) and the hydrogenation reactor (100) for transmitting at least a portion comprising the hydrogen gas to the hydrogenation reactor (100); and

c. a second connection between the fractionation unit (200) and an alkylation reactor (300) to transmit at least a second portion comprising the hydrogen chloride to the alkylation reactor (300).

17. The alkylation process unit of claim 16, wherein the fractionation unit (200) is a distillation column.

18. The alkylation process unit of claim 16, additionally comprising an inlet wherein a hydrocarbon extraction solvent (25) is fed to the fractionation unit (200) or to a separator (400) that is located between the hydrogenation reactor (100) and the fractionation unit (200).

19. The alkylation process unit of claim 18, wherein the inlet is at a location above where the hydrogen gas and the hydrogen chloride are fed to the fractionation unit (200).

20. The alkylation process unit of claim 16, additionally comprising a separator (400) between the hydrogenation reactor (100) and the fractionation unit (200).

21. The alkylation process unit of claim 16, wherein the hydrogenation reactor (100) comprises a hydrogenation catalyst containing Pt and Pd.

22. The alkylation process unit of claim 16, wherein the used ionic liquid catalyst is a chloroaluminate ionic liquid catalyst.

23. The alkylation process unit of claim 16, additionally comprising an ionic liquid catalyst and hydrocarbon separator (500) which separates the offgas (50) into a light hydrocarbon fraction comprising the hydrogen chloride (30), an extracted conjunct polymer naphtha (45), and an ionic liquid catalyst stream (60).

24. The alkylation process unit of claim 16, additionally comprising a third connection between a product treatment unit and the second connection, wherein the second portion is mixed with a recycled stream, from the product treatment unit, comprising a mixture of a gaseous hydrogen chloride and a propane.