Patent ID: 8329128

Claim:
A process for cleaning a gas stream containing carbon dioxide and sulfur dioxide, including removal of carbon dioxide from the gas stream in a carbon dioxide removal stage; the process comprising a) removing, in a sulfur removal stage, sulfur dioxide from the gas stream by bringing the gas stream into direct contact with a liquid comprising ammonia, to absorb into the liquid sulfur dioxide from the gas stream such that the gas stream is depleted in sulfur dioxide; b) cooling, in a gas cooling stage, the gas stream such that a cooled gas stream is formed; c) removing, in the carbon dioxide removal stage, carbon dioxide from the cooled gas stream depleted in sulfur dioxide by bringing the gas stream into contact with ammoniated liquid to absorb into the liquid carbon dioxide from the gas stream such that the gas stream is depleted in carbon dioxide and enriched in ammonia; d) removing, in an ammonia removal stage, ammonia from the gas stream depleted in carbon dioxide by bringing the gas stream into direct contact with an acidic liquid, to absorb into the acidic liquid ammonia from the gas stream such that the gas stream is depleted in ammonia; and e) heating, in a gas heating stage, the gas stream depleted in ammonia such that a heated gas stream is formed; wherein at least a portion of the used liquid from stage a) is withdrawn and directed for reuse in stage a), and at least a portion of the used liquid from stage d) is withdrawn and directed for reuse in stage d).