Method of capturing carbon dioxide from gas streams

• US 7,910,078 B2
• Filed: 08/23/2007
• Issued: 03/22/2011
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: University of Regina
• Original Assignee: University of Regina
• Inventors: Henni, Amr, Maneeintr, Kreangkrai, Fan, Gao-jun, Idem, Raphael, Wee, Andrew G. H., Chakma, Amit, Tontiwachwuthikul, Paitoon, Veawab, Amornvadee, Aroonwilas, Adisorn
• Primary Examiner(s): Lorengo; Jerry
• Assistant Examiner(s): Smith; Jennifer A
• Application Number:
  US11/843,958
• Publication Number:
  US 20080050296A1
• Time in Patent Office: 1,307 Days
• Field of Search: 410/210, 410/226, 410/228, 410/229, 423/228, 423/230, 423/238, 544/170, 546/248, 564/503
• US Class Current: 423/228
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

The present invention relates to a method for removing carbon dioxide (CO₂) from a gas stream. Particularly, the present invention relates to a method for removing CO₂ from a gas stream by a liquid absorbent having an amino alcohol derived from 4-amino-2-butanol. In comparison to conventional amines, the amino alcohols of the present invention have been found to provide a higher CO₂ absorption capacity and a higher cyclic capacity for CO₂ removal.

Claims

1. A method for removing carbon dioxide (CO₂) from a gas stream comprising contacting the gas stream with a liquid absorbent consisting essentially of an aqueous solvent and an amino alcohol of the formula I:

2. The method according to claim 1, wherein R¹ and R² are independently selected from H and C_1-6alkyl.

3. The method according to claim 2, wherein R¹ and R² are independently selected from H and C_1-4alkyl.

4. The method according to claim 1, wherein R¹ and R² are linked to form a 5 to 10-membered carbocyclic ring system.

5. The method according to claim 4, wherein R¹ and R² are linked to form a 5 or 6-membered carbocyclic ring system.

6. The method according to claim 1, wherein the amino alcohol is 4-(diethylamino)-2-butanol.

7. The method according to claim 1, wherein the amino alcohol is 4-(isopropylamino)-2-butanol.

8. The method according to claim 1, wherein the amino alcohol is 4-(piperidino)-2-butanol.

9. The method according to claim 1, wherein the amino alcohol is 4-propylamino-2-butanol.

10. The method according to claim 1, wherein the amino alcohol is 4-(ethyl-methyl-amino)-2-butanol.

11. The method according claim 1, wherein the aqueous solvent solubilizes the amino alcohol and is an absorbent for CO₂.

12. The method according to claim 1, wherein the aqueous solvent is selected from water, a short-chain alcohol and combinations thereof.

13. The method according to claim 12, wherein the aqueous solvent is deionized water.

14. The method according to claim 12, wherein the aqueous solvent is methanol or ethanol.

15. The method according to claim 1, wherein the conditions for absorption of CO₂ by the liquid absorbent and thereby, removal of CO₂ from the gas stream comprise contacting the gas stream with the liquid absorbent at a temperature of about 25°

C. to about 90°

C. and at a pressure of about 1 to about 120 kPa.

16. The method according to claim 15, wherein the conditions for absorption of CO₂ by the liquid absorbent and thereby, removal of CO₂ from the gas stream comprise contacting the gas stream with the liquid absorbent at a temperature of about 40°

C. to about 80°

C. and at a pressure of about 15 to about 110 kPa.

17. The method according to claim 1, wherein the gas stream is a combustion exhaust gas.

18. The method according to claim 17, wherein the combustion exhaust gas is from gas streams of power plants, refineries or cement manufacturers.

19. The method according to claim 1, wherein the gas stream comprises from about 1% to about 100% by volume CO₂.

20. The method according to claim 19, wherein the gas stream comprises from about 9% to about 15% by volume CO₂.

21. The method according to claim 17, wherein the gas stream further comprises oxygen.

22. The method according to claim 1, further comprising releasing the absorbed CO₂ from the liquid absorbent.

23. The method according to claim 22, wherein the CO₂ is released by heating the liquid absorbent, optionally collecting the CO₂ and optionally regenerating the liquid absorbent.

24. A CO₂ absorber, absorption column or absorption tower comprising a liquid absorbent as defined in claim 1.