Patent ID: 7124605

Claim:
A method of separating CO 2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, comprising the steps of: (a) subjecting the inlet stream to fractional distillation providing a CO 2 bottom product stream and a distillation overhead stream; (b) passing the distillation overhead stream to the inlet of a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream; (c) subjecting the hydrocarbon vapor stream from step (b) to membrane separation to provide a hydrocarbon product stream and a permeate stream; (d) compressing the permeate stream from step (c) to provide a compressed permeate stream; and (e) recycling the compressed permeate stream from step (d) to said inlet of said primary reflux drum thereby providing a primary reflux liquid stream and a hydrocarbon gas product vapor stream.