Patent ID: 6336344
Filing Date: 2002-01-08
Classification: F25J,Y10S

Abstract:
A dephlegmator-heat exchanger process for the cryogenic separation from a feed gas stream of a light gas component and a heavy gas component, which process comprises:a) rectifying the feed gas stream in a dephlegmator-heat exchanger to provide a lean component overhead gas stream and a rich liquid stream; b) introducing, during the rectifying step, a selected amount of a liquid hydrocarbon additive into the top or upper portion of the dephlegmator-heat exchanger to maintain the temperature of the dephlegmator-heat exchanger, with a reduced flow rate of the liquid hydrocarbon additive relative to the flow rate required for a conventional, single stage condenser, or to increase the upper temperature of the dephlegmator-heat exchanger for rectification for the same additive flow rate relative to the temperature required for a conventional, single stage condenser, or to obtain selected intermediate values of flow rate and temperature; c) withdrawing the rich liquid stream from a lower portion of the dephlegmator-heat exchanger; and d) withdrawing the lean overhead gas stream from an upper portion of the dephlegmator-heat exchanger.