Patent ID: 6334886
Filing Date: 2002-01-01
Classification: B01D,B01J,C02F,C07C,Y02C,Y02P

Abstract:
In a process for removing CO2 and/or H2S from a gas mixture containing as impurities CO2 and/or H2S and at least one other impurity selected from the group consisting of a cyanide and ammonia, wherein:said gas mixture is conveyed to an absorber vessel and contacted with an aqueous absorbent solution containing an acid gas removal solvent to remove CO2 and/or H2S from said gas mixture and form a rich aqueous absorbent solution enriched in CO2 and/or H2S removed from said gas mixture; said rich aqueous absorbent solution is conveyed from said absorber vessel to a stripping vessel, and thermally stripped of CO2 and/or H2S to form a lean aqueous absorbent solution depleted of CO2 and/or H2S, and an overhead vapor stream rich in CO2 and/or H2S and said at least one other impurity; said lean aqueous absorbent solution is recycled from said stripping vessel to said absorber vessel to absorb additional amounts of said gas mixture; said overhead vapor stream is cooled in a heat exchanger to provide a two phase outlet stream and said two phase outlet stream is separated in a separator vessel to provide an acid gas rich stream and an acid gas removal solvent rich aqueous solution; and recycling said acid gas removal solvent rich aqueous solution for further use in said process, the improvement comprising contacting at least a portion of said acid gas removal solvent rich aqueous solution with an anion exchange resin to remove from said acid gas removal solvent rich aqueous solution at least a part of said at least one other impurity prior to said recycling of said acid gas removal solvent rich aqueous solution for further use in said process.