Removal of carbon dioxide from combusion exhaust gases

Abstract

The invention relates to an absorbent, comprising an aqueous solution (A) of at least one amino acid salt of the formula (I), wherein R1 and R2 independently from each other represent alkyl or hydroxyalkyl, R is hydrogen, alkyl or hydroxyalkyl, or a group R together with R1 is alkylene, M is an alkali metal, and n an integer from 1 to 6, and (B) of at least one primary alkanolamine, which is substantially free of inorganic alkaline salts. The absorbent is used in a method for removing carbon dioxide from a gas flow, particularly combustion exhaust gases. Preferred amino acid salts (A) are N,N-dimethylamino acetic acid potassium salt, N,N-diethylamino acetic acid potassium salt and N-ethyl-N-methylamino acetic acid-potassium salt. Preferred alkanolamines (B) are 2-aminoethanol, 3-aminopropanol, 4-aminobutanol, 2-aminobutanol, 5-aminopentanol, 2-aminopentanol and 2-(2-aminoethoxy)ethanol.

Dependencies are inferred from the claim text.