REMOVAL OF CARBON DIOXIDE FROM FLUE GASES

A process is described for removing carbon dioxide from gas streams in which the partial pressure of the carbon dioxide is less than 200 mbar, in particular flue gases, wherein the gas stream is brought into contact with a liquid absorption medium which comprises an aqueous solution (A) of a tertiary aliphatic alkanolamine and (B) of an activator of the general formula R1-NH-R2-NH2, wherein R1 is C1-C6-alkyl and R2 is C2-C6-alkylene, wherein the sum of the concentrations of A and B is 2.5 to 7 mol/l and the molar ratio of B to A is in the range from 1:3 to 1.5:1. The activator is, for example, 3-methylaminopropylamine, the tertiary aliphatic amine methyldiethanolamine, methyldiisopropanolamine or n-butyldiethanolamine. The process permits a substantial removal of carbon dioxide and regeneration of the absorption medium is possible with a comparatively low energy consumption.