Patent ID: 7554002

Claim:
A method for producing olefins from hydrocarbon-containing feed using a refrigerant and a low-temperature separation stage, said method comprising: introducing a hydrocarbon feed containing olefins into a fractionation stage which is a front end deethanizer which separates the hydrocarbon feed into a first olefin stream containing olefins having at most two carbon atoms, and a second olefin stream containing olefins having at least three carbon atoms; and introducing at least a portion of said first olefin stream into a low-temperature separation stage comprising three condensation stages, operating at temperatures of −50° C. to −100° C., said low-temperature separation stage being connected downstream of said front end deethanizer, wherein the refrigerant used in said three condensation stages consists essentially of a liquid olefin fraction having two carbon atoms removed from said front end deethanizer, and wherein said method omits a compressor cycle for ethylene refrigerant for said condensation stages.