Patent ID: 8146661

Claim:
A method of treating a gas stream, comprising: in a first cryogenic zone, cryogenically separating a first gas stream to form a second gas stream and a third stream, wherein a majority of the second gas stream comprises methane and/or molecular hydrogen and a majority of the third stream comprises one or more carbon oxides, hydrocarbons having a carbon number of at least 2, one or more sulfur compounds, or mixtures thereof; and in a second cryogenic zone, cryogenically contacting the third stream with a carbon dioxide stream to form a fourth stream and a fifth stream, wherein a majority of the fourth stream comprises one or more of the carbon oxides and hydrocarbons having a carbon number of at least 2, and a majority of the fifth stream comprises hydrocarbons having a carbon number of at least 3 and one or more of the sulfur compounds.