Patent ID: 6912872

Claim:
A method for producing a purified liquid stream comprising: providing a feed stream source; introducing under pressure a feed stream from the source to a purification vessel; supplying heat to the feed stream by heat exchange with a compressed refrigerant vapor stream in a first heat exchanger; distilling the feed stream to form a purified vapor; condensing the purified vapor to form purified liquid by heat exchange with a refrigerant liquid stream in a second heat exchanger, wherein the refrigerant liquid stream and the compressed refrigerant vapor stream are provided in a refrigerant flow network comprising the first and second heat exchangers; and withdrawing the purified liquid stream from the purification vessel, wherein the feed stream is a liquid carbon dioxide stream, and at least a portion of the heat supplied to the liquid carbon dioxide feed stream at the first heat exchanger is generated from the condensation of the purified carbon dioxide vapor at the second heat exchanger.