Complex amine absorbent, and device and method for removing one or both of CO2 and H2S

• US 10,137,407 B2
• Filed: 04/25/2013
• Issued: 11/27/2018
• Est. Priority Date: 05/11/2012
• Status: Active Grant

• Current Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Heavy Industries Engineering, Ltd. (Mitsubishi Heavy Industries, Ltd.)
• Inventors: Tanaka, Hiroshi, Nagayasu, Hiromitsu, Hirata, Takuya, Oishi, Tsuyoshi, Kamijo, Takashi
• Primary Examiner(s): Berns, Daniel
• Application Number:
  US14/399,107
• Publication Number:
  US 20150132207A1
• Time in Patent Office: 2,042 Days
• Field of Search: None
• CPC Class Codes: B01D 2252/20405 Monoamines
• CPC Class Codes: B01D 2252/2041 Diamines
• CPC Class Codes: B01D 2252/20421 Primary amines
• CPC Class Codes: B01D 2252/20426 Secondary amines
• CPC Class Codes: B01D 2252/20447 containing a piperazine-ring
• CPC Class Codes: B01D 2252/20484 with one hydroxyl group
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1462 Removing mixtures of hydrogen sulfide and carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/526 Mixtures of hydrogen sulfide and carbon dioxide
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B01J 20/22 comprising organic material
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

An absorbent is prepared by dissolving in water 1) monoethanolamine (MEA) and 2) a primary amine represented by the following formula (1) and having high steric hindrance. Releasability of CO₂ or H₂S during regeneration of the absorbent is thereby improved, and the amount of water vapor used during regeneration of the absorbent in a facility for recovering CO₂ or H₂S can be reduced.

R₁ to R₃: H or a hydrocarbon group having 1 to 3 carbon atoms, at least one of R₁ to R₃ being a hydrocarbon.

Claims

1. A complex amine absorbent for absorbing one or both of CO₂ and H₂S in a gas, the complex amine absorbent comprisingmonoethanolamine (MEA),2-amino-2-methyl-1-propanol, andat least one selected from the group consisting of N,N′

-dimethylethylenediamine, N,N′

-diethylethylenediamine, and N,N′

-dimethylpropanediamine.

2. The complex amine absorbent according to claim 1,

wherein the component 3) is N,N′

-dimethylethylenediamine or N,N′

-dimethylpropanediamine.

3. A device for removing one or both of CO₂ and H₂S, the device comprising:

an absorber for removing one or both of CO₂ and H₂S by bringing a gas containing one or both of CO₂ and H₂S in contact with the complex amine absorbent of claim 1; and

a regenerator for regenerating a solution containing the one or both of CO₂ and H₂S absorbed therein, the absorbent regenerated by removing the one or both of CO₂ and H₂S in the regenerator being reused in the absorber.

4. A method of removing one or both of CO₂ and H₂S, the method comprising:

bringing a gas containing one or both of CO₂ and H₂S in contact with the complex amine absorbent of claim 1 to remove the one or both of CO₂ and H₂S;

regenerating a solution containing one or both of CO₂ and H₂S absorbed therein; and

reusing, in an absorber, the absorbent regenerated by removing the one or both of CO₂ and H₂S in a regenerator.

5. The method for removing one or both of CO₂ and H₂S according to claim 4,

wherein an absolute pressure inside the regenerator is 130 to 200 kPa,

an absorption temperature in the absorber is 30 to 80°

C., and

a regeneration temperature in the regenerator is 110°

C. or higher.