ALKANOLAMINE-BASED CARBON DIOXIDE ABSORPTION SOLUTIONS WITH REDUCED CORROSIVITY

• US 20110262330A1
• Filed: 10/26/2009
• Published: 10/27/2011
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Lonza Limited (Lonza Group AG)
• Original Assignee: Lonza Limited (Lonza Group AG)
• Inventors: Bedard, Thomas, Hall, Larry Kent, Kimler, Joseph
• Granted Patent: US 9,168,487 B2
• Time in Patent Office: Days
• US Class Current: 423/229
• CPC Class Codes: B01D 2251/206 Ammonium compounds
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/77 Liquid phase processes
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: C23F 11/141 Amines; Quaternary ammonium compounds
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

An aqueous carbon dioxide-absorbent solution comprising at least one alkanolamine and at least one quaternary ammonium salt is disclosed. A method of recovering carbon dioxide from a carbon dioxide-containing gaseous mixture and a method of reducing metal corrosion in an alkanolamine-based exhaust gas treating process are also disclosed.

Claims

1. An aqueous carbon dioxide-absorbent solution comprising:

from 10% by weight to 90% by weight, based on the total solution, of at least one alkanolamine having from 2 to 6 carbon atoms, 1 or 2 hydroxyl groups, and a primary, secondary, or tertiary amino group; and

(ii) from 0.03% by weight to 0.20% by weight, based on the total solution, of at least one quaternary ammonium salt of the formula

2. The composition of claim 1, wherein Xⁿ⁻

is selected from the group consisting of bicarbonate, carbonate, phosphates, glycolate and hydroxide.

3. The composition of claim 1, wherein the at least one alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-1-propanol, 2-(ethylamino)-ethanol, 2-(methylamino)-ethanol, and mixtures thereof.

4. The composition of claim 1, wherein the at least one alkanolamine is present in an amount of at least 20% by weight.

5. The composition of claim 4, wherein the at least one alkanolamine is present in an amount of at least 30% by weight.

6. The composition of claim 1, wherein the at least one alkanolamine is present in an amount of no more than 80% by weight.

7. The composition of claim 6, wherein the at least one alkanolamine is present in an amount of no more than 70% by weight.

8. The composition of claim 1, wherein R¹ and R² are independently C_8-12 alkyl groups.

9. The composition of claim 8, wherein R¹ and R² are decyl groups.

10. The composition of claim 1, wherein R³ and R⁴ are methyl groups.

11. The composition of claim 10, wherein the at least one quaternary ammonium salt of formula (I) is selected from the group consisting of didecyldimethylammonium bicarbonate, didecyldimethylammonium carbonate, didecyldimethylammonium phosphate, didecyldimethylammonium glycolate, didecyldimethylammonium hydroxide, and mixtures thereof.

12. The composition of claim 1, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.05% by weight.

13. The composition of claim 12, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.10% by weight.

14. The composition of claim 1, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.18% by weight.

15. The composition of claim 14, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.15% by weight.

16. The composition of claim 1, wherein the alkanolamine is monoethanol-amine and the at least one ammonium salt of formula (I) is didecyldimethylammonium bicarbonate and/or didecyldimethylammonium carbonate.

17. The composition of claim 1, wherein said at least one alkanolamine and said at least one ammonium salt are the only active ingredients in the composition.

18. A method of recovering carbon dioxide from a carbon dioxide-containing gaseous mixture, comprising contacting said carbon dioxide-containing gaseous mixture with an aqueous absorbent solution comprising:

from 10% to 90% by weight, based on the total solution, of at least one alkanolamine having from 2 to 6 carbon atoms, 1 or 2 hydroxyl groups, and a primary, secondary, or tertiary amino; and

(ii) from 0.01% to 1.0% by weight, based on the total solution, of at least one quaternary ammonium salt of the formula

19. The method of claim 18, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of 0.03% by weight to 0.20% by weight.

20. The method of claim 18, wherein the carbon dioxide-containing gaseous mixture is contacted with the aqueous absorbent solution at a temperature of no more than 60°

C.

21. The method of claim 19, wherein the carbon dioxide-containing gaseous mixture is contacted with the aqueous absorbent solution at a temperature of between 60°

C. and 95°

C.

26. The method of claim 18, wherein Xⁿ⁻

is selected from the group consisting of bicarbonate, carbonate, phosphates, glycolate and hydroxide.

27. The method of claim 18, wherein the at least one alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, N-methyldiethanol-amine, 2-amino-2-methyl-1-propanol, 2-(ethylamino)-ethanol, 2-(methylamino)-ethanol, and mixtures thereof.

28. The method of claim 18, wherein the at least one alkanolamine is present in an amount of at least 20% by weight.

29. The method of claim 28, wherein the at least one alkanolamine is present in an amount of at least 30% by weight.

30. The method of claim 18, wherein the at least one alkanolamine is present in an amount of no more than 80% by weight.

31. The method of claim 30, wherein the at least one alkanolamine is present in an amount of no more than 70% by weight.

32. The method of claim 18, wherein R¹ and R² are independently C_8-12 alkyl groups.

33. The method of claim 32, wherein R¹ and R² are decyl groups.

34. The method of claim 18, wherein R³ and R⁴ are methyl groups.

35. The method of claim 18, wherein the at least one quaternary ammonium salt of formula (I) is selected from the group consisting of didecyldimethylammonium bicarbonate, didecyldimethylammonium carbonate, didecyldimethylammonium phosphates, didecyldimethylammonium glycolate, didecyldimethylammonium hydroxide, and mixtures thereof.

36. The method of claim 18, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.05% by weight.

37. The method of claim 36, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.10% by weight.

38. The method of claim 37, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.25% by weight.

39. The method of claim 18, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.75% by weight.

40. The method of claim 39, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.60% by weight.

41. The method of claim 40, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.50% by weight.

42. The method of claim 18, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.18% by weight.

43. The method of claim 42, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.15% by weight.

44. The method of claim 18, wherein the at least one alkanolamine is mono-ethanolamine and the quaternary ammonium salt of formula (I) is didecyldimethyl-ammonium bicarbonate and/or didecyldimethylammonium carbonate.

22. A method of reducing metal corrosion in an alkanolamine-based exhaust gas treating process, said method comprising the step of adding to an aqueous solution containing from 10% to 90% by weight, based on the total solution, of at least one alkanolamine having from 2 to 6 carbon atoms, 1 or 2 hydroxyl groups, and a primary, secondary, or tertiary amino group, from about 0.01% by weight to 1.0% by weight, based on the total solution, of at least one ammonium salt of the formula

23. The method of claim 22, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of 0.03% by weight to 0.20% by weight.

24. The method of claim 22, wherein the gas treating process is operated at a temperature of no more than 60°

C.

25. The method of claim 24, wherein the gas treating process is operated at a temperature between 60°

C. and 95°

C.

45. The method of claim 22, wherein Xⁿ⁻

is selected from the group consisting of bicarbonate, carbonate, phosphates, glycolate and hydroxide.

46. The method of claim 22, wherein the at least one alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, N-methyldiethanol-amine, 2-amino-2-methyl-1-propanol, 2-(ethylamino)-ethanol, 2-(methylamino)-ethanol, and mixtures thereof.

47. The method of claim 22, wherein the at least one alkanolamine is present in an amount of at least 20% by weight.

48. The method of claim 22, wherein the at least one alkanolamine is present in an amount of no more than 80% by weight.

49. The method of claim 22, wherein R¹ and R² are independently C_8-12 alkyl groups.

50. The method of claim 22, wherein R³ and R⁴ are methyl groups.

51. The method of claim 22, wherein the at least one quaternary ammonium salt of formula (I) is selected from the group consisting of didecyldimethylammonium bicarbonate, didecyldimethylammonium carbonate, didecyldimethylammonium phosphates, didecyldimethylammonium glycolate, didecyldimethylammonium hydroxide, and mixtures thereof.

52. The method of claim 22, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of at least 0.05% by weight.

53. The method of claim 22, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.75% by weight.

54. The method of claim 22, wherein the at least one quaternary ammonium salt of formula (I) is present in an amount of no more than 0.18% by weight.

55. The method of claim 22, wherein the at least one alkanolamine is monoethanolamine and the quaternary ammonium salt of formula (I) is didecyldimethylammonium bicarbonate and/or didecyldimethylammonium carbonate.