CO2 ABSORPTION FROM GAS MIXTURES USING AN AQUEOUS SOLUTION OF 4-AMINO-2,2,6,6-TETRAMETHYLPIPERIDINE

• US 20120017762A1
• Filed: 01/29/2010
• Published: 01/26/2012
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Evonik Degussa GmbH (Rag-Stiftung)
• Original Assignee: Evonik Degussa GmbH (Rag-Stiftung)
• Inventors: Seiler, Matthias, Kobus, Axel, Benesch, Wolfgang, Winkler, Hermann, Rolker, Jörn, Schneider, Rolf, Glöckler, Bernd, Riethmann, Thomas, Reich, Jens, Brüggemann, Helmut
• Granted Patent: US 8,500,892 B2
• Time in Patent Office: Days
• US Class Current: 95/203
• CPC Class Codes: B01D 2252/103 Water
• CPC Class Codes: B01D 2252/2041 Diamines
• CPC Class Codes: B01D 2252/20426 Secondary amines
• CPC Class Codes: B01D 2252/20442 containing a piperidine-ring
• CPC Class Codes: B01D 2252/2056 Sulfur compounds, e.g. Sulfolane, thiols
• CPC Class Codes: B01D 2252/30 Ionic liquids and zwitter-ions
• 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: Y02C 20/40 of CO2

Abstract

CO₂ is absorbed from a gas mixture by bringing the gas mixture into contact with an absorbent that comprises water and at least one amine of the formula (I), wherein R¹ and R², independently of each other, are hydrogen or an alkyl group. According to the invention, absorption media comprise sulfolane or an ionic liquid in addition to water and an amine of the formula (I). A device according to the invention for removing CO₂ from a gas mixture comprises an absorption unit, a desorption unit, and an absorption medium according to the invention that is conducted in the circuit.

Claims

1-20. -20. (canceled)

21. An absorption medium for the absorption of CO₂ from a gas mixture, comprising water, sulpholane and at least one amine of formula (I)

22. The absorption medium of claim 21, comprising water and sulpholane in a weight ratio of from 10:

1 to 1;

1.

23. The absorption medium of claim 21, comprising sulpholane and amines of formula (I) in a weight ratio of from 3:

1 to 1;

3.

24. The absorption medium of claim 21, wherein, in formula (I), R¹ and R² are hydrogen.

25. The absorption medium of claim 21, comprising water and amines of formula (I) in a weight ratio of from 10:

1 to 1;

10.

26. The absorption medium of claim 21, comprising at least 5% by weight of amines of formula (I).

27. A method for the absorption of CO₂ from a gas mixture by contacting the gas mixture with an absorption medium according to claim 21.

28. The method of claim 27, wherein the gas mixture is a combustion exhaust gas.

29. The method of claim 27, wherein the absorption medium is present as one phase after the absorption of CO₂.

30. The method of claim 27, wherein CO₂ absorbed in the absorption medium is desorbed by increasing temperature and/or decreasing pressure and the absorption medium after this desorption of CO₂ is reused for the absorption of CO₂.

32. The method of claim 30, wherein the absorption is carried out at a pressure in the range from 0.8 to 50 bar and the desorption at a lower pressure in the range from 0.01 to 10 bar.

31. The method according of 30, wherein the absorption is carried out at a temperature in the range from 0 to 70°

C. and the desorption at a higher temperature in the range from 50 to 200°

C.

33. The method of claim 31, wherein the absorption is carried out at a pressure in the range from 0.8 to 50 bar and the desorption at a lower pressure in the range from 0.01 to 10 bar.

34. A device for separating CO₂ from a gas mixture, said device comprising an absorption unit, a desorption unit and a circulating absorption medium, wherein said absorption medium comprises water, sulpholane and at least one amine of formula (I):

35. The device of claim 34, wherein said absorption medium comprises water and sulpholane in a weight ratio of from 10:

1 to 1;

1.

36. The device of claim 34, wherein said absorption medium comprises sulpholane and amines of formula (I) in a weight ratio of from 3:

1 to 1;

3.

37. The device of claim 34, wherein, in formula (I), R¹ and R² are hydrogen.

38. The device of claim 34, wherein said absorption medium comprises water and amines of formula (I) in a weight ratio of from 10:

1 to 1;

10.

39. The device of claim 34, wherein said absorption medium comprises at least 5% by weight of amines of formula (I).