Separations with ionic liquid solvents

Patent metadata

Field	Value
Publication number	US-9732016-B2
Application number	US-201514966208-A
Country	US
Kind code	B2
Filing date	Dec 11, 2015
Priority date	Jul 23, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Disclosed are systems and methods which provide a process stream comprising a gaseous component, capture the gaseous component from the process stream by an ionic liquid solvent of a separator, and recover a captured gaseous component from the ionic liquid solvent in a regenerator. A second gaseous component from the process stream may be captured by the ionic liquid solvent of the separator, and the second gaseous component may be recovered from the ionic liquid solvent in the regenerator. Alternatively, the second gaseous component from the process stream may be uncaptured by the ionic liquid solvent, and the uncaptured second gaseous component may be recovered from a membrane unit.

First claim

We claim:

1. A method comprising:
providing a process stream comprising an olefin;
capturing at least a portion of the olefin from the process stream by an ionic liquid solvent, wherein the capturing is performed at a liquid-to-gas mass flow ratio from about 1 to about 350; and
recovering at least a portion of a captured olefin from the ionic liquid solvent.

2. The method of claim 1 , wherein the ionic liquid solvent comprises a cation and an anion; wherein the cation comprises an ethylmethylimidazolium cation, a butylmethylimidazolium cation, a butylmethylpyridinium cation, or combinations thereof; wherein the anion comprises a bis(trifluoromethanesulfonyl)amide anion, a hexafluorophosphate anion, a trifluoromethanesulfonate anion, a dicyanamide anion, a tetrafluoroborate anion, a thiocyanate anion, a nitrate anion, a sulfonate anion, a methylsulfate anion, or combinations thereof.

3. The method of claim 1 , wherein the ionic liquid solvent comprises a Ag(I) salt, a Cu(I) salt, or combinations thereof.

4. The method of claim 3 , wherein the Ag(I) salt comprises silver(I) bis(trifluoromethanesulfonyl)amide, silver(I) trifluoromethanesulfonate, silver(I) nitrate, or combinations thereof.

5. The method of claim 3 , wherein the Cu(I) salt comprises copper(I) chloride, copper(I) bromide, cuprous trifluoroacetate, copper(I) nitrate, or combinations thereof.

6. The method of claim 3 , wherein a concentration of silver, copper, or both, in the ionic liquid solvent is from about 0.1 N to about 5 N.

7. The method of claim 6 , wherein the concentration of silver, copper, or both, in the ionic liquid is from about 0.45 N to about 1.8 N.

8. The method of claim 1 , further comprising:
flowing the ionic liquid solvent at a mass flow rate from about 1,000 pounds per hour to about 300,000 pounds per hour.

9. The method of claim 1 , wherein the process stream further comprises an alkane.

10. The method of claim 9 , wherein the capturing is performed at a liquid-to-gas mass flow ratio such that at least a portion of the alkane is captured by the ionic liquid solvent in addition to the capture of at least a portion of the olefin.

11. The method of claim 10 , wherein at least a portion of the alkane is captured by absorption, dissolution, adsorption, complexation, or combinations thereof.

12. The method of claim 10 , further comprising:
recovering at least a portion of a captured alkane from the ionic liquid solvent.

13. The method of claim 12 , wherein recovering at least a portion of a captured alkane is performed at a temperature greater than the temperature at which the alkane is captured and at a pressure less than the pressure at which the alkane is captured.

14. The method of claim 9 , wherein said capturing is performed at a liquid-to-gas mass flow ratio such that at least a portion of the alkane from the process stream is not captured by the ionic liquid solvent.

15. The method of claim 14 , further comprising:
flowing an uncaptured portion of the alkane to a membrane unit; and
recovering at least a portion of the uncaptured portion of the alkane from the membrane unit.

16. The method of claim 9 , wherein the alkane comprises isobutane, wherein the olefin comprises ethylene.

17. The method of claim 1 , wherein the olefin comprises ethylene.

18. The method of claim 1 , wherein the olefin is captured by the ionic liquid solvent at a temperature from about 20° C. to about 40° C.

19. The method of claim 1 , wherein the olefin is captured by the ionic liquid solvent at a pressure from about 100 psia to about 250 psia.

20. The method of claim 1 , wherein at least a portion of the olefin is captured by absorption, adsorption, dissolution, complexation or combinations thereof.

21. The method of claim 1 , wherein recovering at least a portion of a captured olefin comprises:
liberating at least a portion of the captured olefin from the ionic liquid solvent; and
recovering the liberated olefin.

22. The method of claim 1 , wherein recovering at least a portion of a captured olefin is performed at a temperature greater than the temperature at which the olefin is captured and at a pressure less than the pressure at which the olefin is captured.

23. A method comprising:
providing a process stream comprising an olefin, wherein the process stream further comprises an alkane;
capturing at least a portion of the olefin from the process stream by an ionic liquid solvent, wherein the capturing is performed at a liquid-to-gas mass flow ratio such that at least a portion of the alkane is captured by the ionic liquid solvent in addition to the capture of at least a portion of the olefin; and
recovering at least a portion of a captured olefin from the ionic liquid solvent,
wherein the liquid-to-gas mass flow ratio is greater than about 15.

24. The method of claim 23 , wherein the ionic liquid solvent comprises a cation and an anion; wherein the cation comprises an ethylmethylimidazolium cation, a butylmethylimidazolium cation, a butylmethylpyridinium cation, or combinations thereof; wherein the anion comprises a bis(trifluoromethanesulfonyl)amide anion, a hexafluorophosphate anion, a trifluoromethanesulfonate anion, a dicyanamide anion, a tetrafluoroborate anion, a thiocyanate anion, a nitrate anion, a sulfonate anion, a methylsulfate anion, or combinations thereof.

25. The method of claim 23 , wherein the ionic liquid solvent comprises a Ag(I) salt, a Cu(I) salt, or combinations thereof.

26. The method of claim 25 , wherein the Ag(I) salt comprises silver(I) bis(trifluoromethanesulfonyl)amide, silver(I) trifluoromethanesulfonate, silver(I) nitrate, or combinations thereof.

27. The method of claim 25 , wherein the Cu(I) salt comprises copper(I) chloride, copper(I) bromide, cuprous trifluoroacetate, copper(I) nitrate, or combinations thereof.

28. The method of claim 25 , wherein a concentration of silver, copper, or both, in the ionic liquid solvent is from about 0.1 N to about 5 N.

29. The method of claim 28 , wherein the concentration of silver, copper, or both, in the ionic liquid is from about 0.45 N to about 1.8 N.

30. A method comprising:
providing a process stream comprising an olefin, wherein the process stream further comprises an alkane;
capturing at least a portion of the olefin from the process stream by an ionic liquid solvent, wherein the capturing is performed at a liquid-to-gas mass flow ratio such that at least a portion of the alkane from the process stream is not captured by the ionic liquid solvent; and
recovering at least a portion of a captured olefin from the ionic liquid solvent,
wherein the liquid-to-gas mass flow ratio is less than about 200.

31. The method of claim 30 , wherein the ionic liquid solvent comprises a cation and an anion; wherein the cation comprises an ethylmethylimidazolium cation, a butylmethylimidazolium cation, a butylmethylpyridinium cation, or combinations thereof; wherein the anion comprises a bis(trifluoromethanesulfonyl)amide anion, a hexafluorophosphate anion, a trifluoromethanesulfonate anion, a dicyanamide anion, a tetrafluoroborate anion, a thiocyanate anion, a nitrate anion, a sulfonate anion, a methylsulfate anion, or combinations thereof.

32. The method of claim 30 , wherein the ionic liquid solvent comprises a Ag(I) salt, a Cu(I) salt, o

Assignees

• Chevron Phillips Chemical Co Lp
• Chevron Usa Inc

Inventors

• Ji Lei
• Chang Ai-Fu
• Driver Michael S
• Timken Hye Kyung

Classifications

• B01D53/1462

  Removing mixtures of hydrogen sulfide and carbon dioxide · CPC title

• C01B17/167

  Separation · CPC title

• B01D2256/22

  Carbon dioxide · CPC title

• C01B31/20

  Chemistry & Metallurgy · mapped topic

• C07C11/04

  Ethene · CPC title