Patent ID: 8337587

Claim:
A process for the recovery of carbon dioxide from a gas mixture, the process comprising: pretreating a feed gas mixture comprising carbon dioxide, water vapor, and one or more light gases selected from the group consisting of methane, oxygen, nitrogen and argon in a pretreating system to form a cooled gas mixture, wherein pretreating includes compressing in a first compressor and cooling in a first heat exchanger using a first cooling fluid; fractionating the cooled gas mixture in a first fractionator to recover a bottoms fraction comprising carbon dioxide and an overheads fraction comprising carbon dioxide and at least a portion of the light gases; cooling the overheads fraction in a second heat exchanger using a second cooling fluid to form a liquid recycle stream and a vapor stream, passing at least a portion of the vapor stream over a membrane selective to carbon dioxide to separate a carbon dioxide permeate from a residue gas comprising light gases; recycling the carbon dioxide permeate to the pretreating system; and removing at least a portion of the bottoms fraction from the first fractionator as a purified carbon dioxide product stream containing at least 95% carbon dioxide by volume, wherein at least 90 mol % of the carbon dioxide from the feed gas mixture is recovered in the purified carbon dioxide product stream.