Method for removing carbon dioxide from combustion exhaust gas

• US 5,700,437 A
• Filed: 06/10/1996
• Issued: 12/23/1997
• Est. Priority Date: 10/06/1993
• Status: Expired due to Term

• Current Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Jukogyo Kabushiki Kaisha
• Original Assignee: Kansai Electric Power Company Incorporated, Mitsubishi Jukogyo Kabushiki Kaisha
• Inventors: Iijima, Masaki, Mimura, Tomio, Kitamura, Koichi, Mitsuoka, Shigeaki, Shimojo, Shigeru, Fujii, Masumi, Hotta, Yoshitsugu, Suda, Taiichiro, Jinno, Yukihiro
• Primary Examiner(s): Straub, Gary P.
• Assistant Examiner(s): Vanoy, Timothy C.
• Application Number:
  US08/660,837
• Time in Patent Office: 561 Days
• Field of Search: 423/220, 423/228, 423/229, 95/236
• US Class Current: 423/220
• 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: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

A method for removing carbon dioxide from a combustion exhaust gas under atmospheric pressure by the use of a mixed solution of a specific amine compound X having an alcoholic hydroxyl group and a primary amino group which is bonded to a tertiary carbon atom having two unsubstituted alkyl groups and another amine compound Y being a diaminotoluene (DAT) selected from the group consisting of 2,3-DAT, 2,4-DAT, 2,5-DAT, 2,6-DAT, 3,4-DAT and 3,5-DAT.

Claims

1. A method for removing carbon dioxide from a combustion exhaust gas comprising the steps of bringing the exhaust gas under atmospheric pressure into contact with a mixed aqueous solution of 100 parts by weight of an amine compound X and 1-25 parts by weight of an amine compound Y;

said amine compound X having an alcoholic hydroxyl group and a primary amino group which is bonded to a tertiary carbon atom having two unsubstituted alkyl groups;

said amine compound Y being a diaminotoluene (DAT) selected from the group consisting of 2,3-DAT, 2,4-DAT, 2,5-DAT, 2,6-DAT, 3,4-DAT and 3,5-DAT.

2. The method according to claim 1 wherein the amine compound X is a compound selected from the group consisting of 2-amino-2-methyl-1-propanol, 3-amino-3-methyl-2-pentanol, 2,3-dimethyl-3-amino-1-butanol, 2-amino-2-ethyl-1-butanol, 2-amino-2-methyl-3-pentanol, 2-amino-2-methyl-1-butanol, 3-amino-3-methyl-1-butanol, 3-amino-3-methyl-2-butanol, 2-amino-2,3-dimethyl-3-butanol, 2-amino-2,3-dimethyl-1-butanol, and 2-amino-2-methyl-1-pentanol.

3. The method according to claim 2 wherein the amine compound X is 2-amino-2-methyl-1-propanol.

4. The method according to claim 1 wherein a mixing ratio of the amine compound X to the amine compound Y is 100:

1-10 in terms of parts by weight.

5. The method of claim 1 wherein the concentration of amine compound X in the mixed aqueous amine solution is in the range of 15-65% by weight.