Patent ID: 7257966
Filing Date: 2007-08-21
Classification: F25J

Abstract:
1. A process for recovering relatively less volatile components from a gas mixture while rejecting relatively more volatile components as a residue gas via one or more cryogenic distillation columns wherein internal refrigeration is employed and generated by steps comprising: a) withdrawing an open cycle refrigerant from one or more locations in a distillation column; b) combining at least a portion of said open cycle refrigerant and at least a portion of said closed cycle refrigerant from the dividing step (g) below to form a mixed refrigerant; c) reducing the pressure of said mixed refrigerant for utilizing the resultant refrigeration in other portions of the process by increasing its temperature, and forming a heated mixed refrigerant; d) separating said heated mixed refrigerant into a first vapor stream and a first liquid stream; e) increasing the pressure of said first vapor stream and thereafter reducing its temperature to form a partially condensed stream; f) separating said partially condensed stream into a second vapor stream and a second liquid stream; g) dividing said second liquid stream into a closed cycle refrigerant and a remaining liquid portion; and h) introducing said second vapor stream as an enhancement vapor to a distillation column selected from the group consisting of: