Phosphonium-based ionic liquids and their use in the capture of polluting gases

Patent metadata

Field	Value
Publication number	US-9670237-B2
Application number	US-201113240275-A
Country	US
Kind code	B2
Filing date	Sep 22, 2011
Priority date	Sep 22, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

An ionic liquid composition having the following chemical structural formula:

wherein R 1 , R 2 , R 3 , and R 4 are independently selected from hydrocarbon groups containing at least 1 and up to 20 carbon atoms, and X − is a cyclic anion that possesses a negatively-charged group reactive with a gaseous electrophilic species, particularly carbon dioxide or sulfur dioxide. Methods for capturing a gaseous electrophilic species, such as CO 2 or SO 2 , by contacting the gaseous electrophilic species with an ionic liquid according to Formula (1) are also described.

First claim

What is claimed is:

1. An ionic liquid composition having the following chemical structural formula:

wherein R 1 , R 2 , R 3 , and R 4 are independently selected from hydrocarbon groups containing at least 1 and up to 20 carbon atoms, wherein at least one of R 1 , R 2 , R 3 , and R 4 is an alkyl or alkenyl group, provided that at least one of R 1 , R 2 , R 3 , and R 4 contains at least four more carbon atoms than another of R 1 , R 2 , R 3 , and R 4 ; and X − is a deprotonated phenolic or thiophenolic anion reactive with carbon dioxide or sulfur dioxide.

2. The ionic liquid composition of claim 1 , wherein R 1 , R 2 , R 3 , and R 4 contain at least 3 and up to 20 carbon atoms.

3. The ionic liquid composition of claim 1 , wherein R 1 , R 2 , R 3 , and R 4 contain at least 4 and up to 20 carbon atoms.

4. The ionic liquid composition of claim 1 , wherein R 1 , R 2 , R 3 , and R 4 contain at least 5 and up to 20 carbon atoms.

5. The ionic liquid composition of claim 1 , wherein R 1 , R 2 , R 3 , and R 4 contain at least 6 and up to 20 carbon atoms.

6. The ionic liquid composition of claim 1 , wherein at least two of R 1 , R 2 , R 3 , and R 4 are alkyl groups.

7. The ionic liquid composition of claim 1 , wherein said hydrocarbon groups are alkyl groups.

8. The ionic liquid composition of claim 1 , wherein at least two of R 1 , R 2 , R 3 , and R 4 are not equivalent.

9. The ionic liquid composition of claim 1 , wherein at least one of R 1 , R 2 , R 3 , and R 4 contains at least five more carbon atoms than another of R 1 , R 2 , R 3 , and R 4 .

10. The ionic liquid composition of claim 1 , wherein at least one of R 1 , R 2 , R 3 , and R 4 contains at least six more carbon atoms than another of R 1 , R 2 , R 3 , and R 4 .

11. The ionic liquid composition of claim 1 , wherein said deprotonated phenolic or thiophenolic anion does not possess a carboxylate substituent.

12. The ionic liquid composition of claim 1 , wherein said deprotonated phenolic or thiophenolic anion is not an amino acid.

13. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a viscosity of no more than 2000 cP at 25° C.

14. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a viscosity of no more than 1500 cP at 25° C.

15. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a viscosity of no more than 1000 cP at 25° C.

16. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a decomposition temperature of at least 150° C.

17. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a CO 2 absorption capacity of at least 0.7 moles CO 2 per mole of ionic liquid.

18. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a CO 2 absorption capacity of at least 0.8 moles CO 2 per mole of ionic liquid.

19. The ionic liquid composition of claim 1 , wherein said ionic liquid possesses a CO 2 absorption capacity of at least 0.9 moles CO 2 per mole of ionic liquid.

20. A method for capturing a gaseous electrophilic species, the method comprising contacting said gaseous electrophilic species with an ionic liquid according to claim 1 .

21. The method according to claim 20 , further comprising removing captured electrophilic gas from said ionic liquid to produce fresh ionic liquid, and re-using said fresh ionic liquid for capturing additional electrophilic gas.

22. A method for capturing gaseous carbon dioxide, the method comprising contacting said carbon dioxide with an ionic liquid according to claim 1 .

23. The method according to claim 22 , wherein the carbon dioxide is nucleophilicly attacked by the deprotonated phenolic or thiophenolic anion.

24. The method according to claim 22 , wherein the carbon dioxide is not protonated during the reaction.

25. The method according to claim 22 , wherein said method for capturing gaseous carbon dioxide is integrated with a process that produces carbon dioxide as a byproduct.

26. The method according to claim 25 , wherein said process that produces carbon dioxide as a byproduct is a combustion process.

27. A method for capturing atmospheric sulfur dioxide, the method comprising contacting said sulfur dioxide with an ionic liquid according to claim 1 .

28. The method according to claim 27 , wherein the sulfur dioxide is nucleophilicly attacked by the deprotonated phenolic or thiophenolic anion.

29. The method according to claim 27 , wherein the sulfur dioxide is not protonated during the reaction.

30. The method according to claim 27 , wherein said method for capturing atmospheric sulfur dioxide is integrated with a process that produces sulfur dioxide as a byproduct.

31. The method according to claim 30 , wherein said process that produces sulfur dioxide as a byproduct is a combustion process.

32. The method of claim 31 , wherein said combustion process is a coal-powered process.

33. An ionic liquid composition having the following chemical structural formula:

wherein R 1 , R 2 , R 3 , and R 4 are independently selected from hydrocarbon groups containing at least 1 and up to 20 carbon atoms, provided that at least one of R 1 , R 2 , R 3 , and R 4 contains at least four more carbon atoms than another of R 1 , R 2 , R 3 , and R 4 ; and X − is a deprotonated phenolic or thiophenolic anion reactive with carbon dioxide or sulfur dioxide.

34. A method for capturing a gaseous electrophilic species, the method comprising contacting said gaseous electrophilic species with an ionic liquid according to claim 33 .

35. The method of claim 34 , wherein the gaseous electrophilic species is carbon dioxide or sulfur dioxide.

Assignees

• Dai Sheng
• Wang Congmin
• Luo Huimin
• Jiang De-En
• Ut Battelle Llc

Inventors

• Dai Sheng
• Wang Congmin
• Luo Huimin
• Jiang De-En

Classifications

• Y02C10/04

  Cross-Sectional Technologies · mapped topic

• B01F17/0064

  Operations & Transport · mapped topic

• C07F9/5407 Primary

  Acyclic saturated phosphonium compounds · CPC title

• Y02C20/40

  of CO2 · CPC title

• C09K23/14

  Derivatives of phosphoric acid · CPC title