Absorbing Solution, Method and Device for Absorbing CO2 or H2S or Both

• US 20080078292A1
• Filed: 04/03/2006
• Published: 04/03/2008
• Est. Priority Date: 04/04/2005
• Status: Active Grant

• Current Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Heavy Industries Engineering, Ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Heavy Industries, Ltd.
• Inventors: Takashima, Toru, Tanaka, Hiroshi, Iijima, Masaki, Ogura, Kouki, Mimura, Tomio, Yagi, Yasuyuki, Hirata, Takuya
• Granted Patent: US 8,147,593 B2
• Time in Patent Office: Days
• US Class Current: 95/187
• CPC Class Codes: B01D 2252/103 Water
• 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 2252/20431 Tertiary amines
• CPC Class Codes: B01D 2252/20447 containing a piperazine-ring
• CPC Class Codes: B01D 2252/20489 with two or more hydroxyl groups
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 2252/604 Stabilisers or agents inhibiting degradation
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2258/06 Polluted air
• 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: C10L 3/10 Working-up natural gas or synthetic natural gas
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

An absorbing solution according to the present invention is an absorbing solution that absorbs CO₂ or H₂S in gas or both of CO₂ and H₂S. The absorbing solution is formed by adding desirably 1 to 20 weight percent of tertiary monoamine to a secondary-amine composite absorbent such as a mixture of secondary monoamine and secondary diamine. Consequently, it is possible to control degradation in absorbing solution amine due to oxygen or the like in gas. As a result, it is possible to realize a reduction in an absorption loss, prevention of malfunction, and a reduction in cost. This absorbing solution is suitably used in an apparatus for removing CO₂ or H₂S or both of CO₂ and H₂S.

Claims

1-7. -7. (canceled)

8. An absorbing-solution that absorbs at least one of CO₂ and H₂S that are present in a gas, the absorbing-solution comprising:

secondary-amine composite absorbent; and

tertiary monoamine that is added to the secondary-amine composite absorbent.

9. The absorbing-solution according to claim 8, wherein the secondary-amine composite absorbent is a mixture of secondary monoamine and secondary diamine.

10. The absorbing-solution according to claim 9, wherein

the secondary monoamine is a compound that is selected from at least one kind of 2-methylaminoethanol, 2-ethylaminoethanol, 2-n-propylaminoethanol, 2-n-butylaminoethanol, 2-n-pentylaminoethanol, 2-isopropylaminoethanol, 2-sec-butyleamnoethanol, and 2-isobutylaminoethanol, and

the secondary diamine is a compound that is selected from at least one kind of piperazine, 2-metylpiperazine, 2,3-dimetylpiperazine, 2,5-dimetylpiperazine, N,N′

-dimetylethanediamine, N,N′

-dimetylpropanediamine, N,N′

-diethylethylenediamine, N,N′

-diethylpropanediamine, N,N′

-diisopropylethylenediamine, and N,N′

-ditartiary-butylethanediamine.

11. The absorbing-solution according to claim 8, wherein 1 weight percent to 20 weight percent of the tertiary monoamine is added to the secondary-amine composite absorbent.

12. The absorbing-solution according to claim 9, wherein 2.5 weight percent to 100 weight percent of the secondary diamine is added to the secondary monoamine.

13. A removing apparatus that removes any one of CO₂ and H₂S or both that are present in a gas, the removing apparatus comprising:

an absorber that receives the gas, causes the gas to come in contact with an absorbing-solution whereby any one of CO₂ and H₂S or both is absorbed by the absorbing-solution; and

a regenerator that regenerates the absorbing-solution that absorbed any one of CO₂ and H₂S or both by removing any one of CO₂ and H₂S or both from the absorbing-solution, and supplies the absorbing-solution that is removed of any one of CO₂ and H₂S or both to the absorber, wherein

the absorbing-solution includes secondary-amine composite absorbent, and tertiary monoamine that is added to the secondary-amine composite absorbent.

14. A method of removing apparatus to remove any one of CO₂ and H₂S or both that are present in a gas, the method comprising:

causing the gas to come in contact with an absorbing-solution whereby any one of CO₂ and H₂S or both is absorbed by the absorbing-solution; and

regenerating the absorbing-solution that absorbed any one of CO₂ and H₂S or both by removing any one of CO₂ and H₂S or both from the absorbing-solution, wherein

the causing includes causing the gas to come in contact with an absorbing-solution that is regenerated at the regenerating, wherein

the absorbing-solution includes secondary-amine composite absorbent, and tertiary monoamine that is added to the secondary-amine composite absorbent.