Patent ID: 8663364

Claim:
A method of obtaining carbon dioxide from a CO 2 -containing gas mixture, said method comprising the steps of: obtaining a CO 2 -containing gas mixture; cooling the gas mixture in a heat exchanger to a temperature from 5° C. to about −60° C.; flowing the cooled gas mixture into a gas separation membrane module to produce a carbon dioxide-rich permeate and a carbon dioxide-lean non-permeate; expanding the carbon dioxide-lean stream to produce a cold carbon dioxide-lean stream; compressing the carbon dioxide-rich permeate; partially condensing the compressed carbon dioxide-rich permeate via cooling in the heat exchanger; separating the partially condensed compressed carbon dioxide-rich permeate into a CO 2 rich liquid and a CO 2 lean vapor stream; providing cold energy to the heat exchanger with the CO 2 lean vapor stream by passing the CO 2 lean vapor stream through the heat exchanger, wherein the CO 2 lean vapor stream is expanded but not until after it has passed through the heat exchanger; warming the expanded CO 2 lean vapor stream; and combining the warmed expanded CO 2 lean vapor stream with the gas mixture.