| abstract |
The invention relates to an absorbent, comprising an aqueous solution (A) of at least one amino acid salt of the formula (I), wherein R<SUP>1</SUP> and R<SUP>2</SUP> independently from each other represent alkyl or hydroxyalkyl, R is hydrogen, alkyl or hydroxyalkyl, or a group R together with R<SUP>1</SUP> 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. |