Method for the removal of carbon dioxide from combustion exhaust gas

摘要

This invention provides a method for the removal of CO2 present in combustion exhaust gas which comprises bringing combustion exhaust gas at atmospheric pressure into contact with a mixed aqueous solution containing 100 parts by weight of an amino acid metal salt (X), 1 to 25 parts by weight of piperazine (Y), and optionally a copper compound in such an amount as to give a divalent copper ion concentration of 10 to 1,000 ppm based on the mixed aqueous solution, the amino acid metal salt being of the general formula CH3NR1CHR2COOM (1) wherein R1 and R2 represent hydrogen atoms or lower alkyl groups, provided that R2 is a lower alkyl group when R1 is a hydrogen atom, and R2 is a hydrogen atom when R1 is a lower alkyl group, and M represents an alkali metal. Potassium dimethylaminoacetate is a preferred amino acid metal salt (X).