Patent ID: 7388120

Claim:
A process for removing CO 2 from an effluent stream, wherein the process comprises the steps of: (a) providing the effluent stream from an oxygenate to olefin process, wherein the effluent stream comprises greater than about 100 vppm CO2; (b) contacting the effluent stream with a first CO 2 removal medium in a first CO 2 removal zone under conditions effective to remove a first portion of the CO 2 from the effluent stream and form a first CO 2 depleted stream comprising from about 0.5 to about 200 vppm CO 2 , wherein the first CO 2 removal medium has a weight ratio of fresh caustic to spent caustic, on a dry basis, of greater than about 1.5 and less than about 4.5; and (c) contacting the first CO 2 depleted stream with a second CO2 removal medium in a second CO 2 removal zone under conditions effective to remove a second portion of the CO 2 from the first CO 2 depleted stream and form a second CO 2 depleted stream comprising less than about 0.5 vppm CO 2 .