Selective absorption of chlorine from waste gas containing carbon dioxide

PURPOSE: To provide an excellent method to selectively absorb chlorine from a CO 2 -rich waste gas by washing the waste gas with an aq. soln. containing specified amts. of NaHCO 3 and NaHSO 3 . CONSTITUTION: In a method to selectively absorb chlorine from a waste gas containing CO 2 , the waste gas is washed with an aq. soln. containing 0.1 to 10 wt.% NaHCO 3 and 0.01 to 5 wt.% NaHSO 3 . By using the NaHCO 3 soln. added with a small amt. of NaHSO 3 , substantially all Cl 2 can be removed without absorbing CO 2 even when the washing liquid is repeatedly used. Or, NaOH can be added to the washing liquid instead of NaHCO 3 (because NaOH directly reacts with CO 2 in the waste gas to produce NaHCO 3 ). Thereby, an excellent method to absorb Cl 2 in especially a CO 2 -rich gas can be provided. COPYRIGHT: (C)1991,JPO