# US 5,700,437 A · Method for removing carbon dioxide from combustion exhaust gas

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- Number: US 5,700,437 A
- Document ID: US5700437A
- Status: Granted
- Kind: A
- Application number: 08/660,837
- Filed: 1996-06-10
- Granted: 1997-12-23
- Earliest claimed: 1993-10-06
- Assignees: The Kansai Electric Power Co., Inc.; Mitsubishi Jukogyo Kabushiki Kaisha
- Inventors: Masumi Fujii; Taiichiro Suda; Yoshitsugu Hotta; Koichi Kitamura; Yukihiro Jinno; Tomio Mimura; Shigeru Shimojo; Masaki Iijima; Shigeaki Mitsuoka
- Web page: https://patentgrep.com/patent/US5700437A

## CPC

- B01D 53/1475: {Removing carbon dioxide}
- B01D 53/1493: {Selection of liquid materials for use as absorbents}
- B01D 2257/504: Carbon dioxide
- Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- Y02C 20/40: of CO2
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]

## 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

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 2)

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

### Claim 4 (depends on 1)

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.

### Claim 5 (depends on 1)

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.