Abstract: The present invention provides a process for recovering a basic amine compound which comprises the steps of (a) supplying a CO.sub.2 -containing gas to a carbon dioxide absorption unit in which an absorbing solution, which contains a basic amine compound, absorbs carbon dioxide; (b) bringing the gas, from which carbon dioxide has been removed, into vapor-liquid contact with a washing water at a temperature from 20 to 60.degree. C. in an amine recovering unit of a carbon dioxide removal tower, recovering part of the basic amine compound accompanying the gas into the water phase and discharging the gas as an exhaust gas of the carbon dioxide removal tower; and (c) collecting the basic amine compound which remains in the exhaust gas of the carbon dioxide removal tower by passing the exhaust gas pass through a demister at a temperature from 20 to 60.degree. C. The basic amine compound can be recovered efficiently from the gas of the carbon dioxide removal tower by using the above process.

Abstract: This invention relates to the process for removing CO.sub.2 from CO.sub.2 -containing gas such as combustion gas. For example, it is the process for removing CO.sub.2 from combustion gas through the contact of the gas at the atmospheric pressure with an aqueous solution of an amine represented by the general formula R.sup.1 NHC(CH.sub.3).sub.2 CH.sub.2 OH in which R.sup.1 is a lower alkyl group having 1-4 carbon atoms, or an aqueous solution containing both an amine represented by the general formula R.sub.2 CHR.sub.3 NHCH.sub.2 CH.sub.2 OH in which R.sup.2 is a hydrogen atom or a lower alkyl group having 1-4 carbon atoms and R.sup.3 is a hydrogen atom or methyl group and a piperazine compound selected from the group consisting of piperazine, 2-methylpiperazine, 2,3-dimethylpiperazine, and 2,5-dimethylpiperazine, or an mixed aqueous amine solution containing a secondary amine and a tertiary amine at concentrations of 10-45% by weight each, or an aqueous solution of a piperazine derivative.