Absorbent, CO 2 or H 2 S reducing apparatus, and CO 2 or H 2 S reducing method using absorbent

• US 8,597,418 B2
• Filed: 06/17/2008
• Issued: 12/03/2013
• Est. Priority Date: 06/18/2007
• 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: Inoue, Yukihiko, Yoshiyama, Ryuji, Oishi, Tsuyoshi, Iijima, Masaki, Tanoura, Masazumi, Mimura, Tomio, Yagi, Yasuyuki
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): MCKENZIE, THOMAS B
• Application Number:
  US12/665,393
• Publication Number:
  US 20100180764A1
• Time in Patent Office: 1,995 Days
• Field of Search: 423/149, 423/183, 423/186, 423187-204, 423210-248, 95149-266, 96243-371, 96155-220, 502/401
• US Class Current: 96/234
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• 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 53/18 Absorbing units; Liquid distributors therefor B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

An absorbent according to the present invention absorbs CO₂ or H₂S contained in flue gas emitted from a power generating plant such as a thermal plant, and contains three or more amine compounds selected from linear or cyclic amine compounds having a primary amino group, and linear or cyclic amine compounds having a secondary amino group. By way of a synergetic effect of the mixture of these compounds, the absorption speed of CO₂ or H₂S absorption is improved. A small amount of CO₂ contained in a large amount of boiler flue gas can be absorbed efficiently.

Claims

1. An absorbent that absorbs CO₂ or H₂S contained in gas, the absorbent consisting essentially of:

a main component which is 2-n-butylaminoethanol (n-BAE);

minor components selected from any two of piperazine (P), 1-(2-aminoethyl)piperazine (AEPRZ), 2-amino-2-methylpropanol (AMP), and piperidinol (PDN); and

water,

wherein the main component accounts for 30 to 55 weight percent, the minor components account for 20 to 1 weight percent, and the water accounts for the remaining weight percent.

2. A CO₂ or H₂S reducing apparatus that reduces CO₂ or H₂S contained in gas, the CO₂ or H₂S reducing apparatus comprising:

an absorber that brings gas containing CO₂ or H₂S into contact with absorbent to reduce CO₂ or H₂S contained in the gas; and

a regenerator that recycles a solvent that has absorbed CO₂ or H₂S, wherein

the solvent having CO₂ or H₂S reduced and recycled in the regenerator is reused in the absorber, and

the absorbent according to claim 1 is used.

3. A CO₂ or H₂S reducing method comprising:

reducing CO₂ or H₂S in gas by bringing the gas containing CO₂ or H₂S into contact with absorbent, and

recycling a solvent that has absorbed CO₂ or H₂S so that the solvent having CO₂ or H₂S reduced and recycled is reused, wherein

the absorbent according to claim 1 is used as the absorbent.