Patent ID: 6245127
Filing Date: 2001-06-12
Classification: B01D,Y02C

Abstract:
A pressure swing adsorption process for the recovery of at least a heavy gas component from a multi-component gas mixture that includes said heavy gas and one or more light gas components, which comprises:(1) feeding the multi-component gas mixture into an inlet of and through at least one adsorber and at an adsorption pressure, adsorbing the heavy component of the gas mixture on an adsorbent within the adsorber and removing an effluent enriched with the light component or components of the mixture from the adsorber through an outlet thereof, at least a portion of the light component-enriched effluent being retained in a pressure zone communicating with the adsorber outlet;(2) blowing down a portion of the light component-enriched effluent cocurrently through the adsorber outlet into a vacuum zone maintained at a pressure less than said adsorption pressure and communicating with the adsorber and, at the same time, removing desorbed gas by countercurrent evacuation from the adsorber through the adsorber inlet, to simultaneously depressurize the adsorber cocurrently from its outlet and countercurrently from its inlet;(3) terminating the flow of the blowdown gas through the adsorber outlet while continuing the countercurrent evacuation of the desorbed gas from the adsorber inlet to further depressurize the adsorber until the pressure in the adsorber is less than that in the vacuum zone;(4) passing the blowdown gas as a purge gas stream from the vacuum zone to the adsorber outlet countercurrently to and through the adsorber to make and recover a product stream enriched in the heavy gas component;(5) terminating the flow of the blowdown gas from the vacuum zone and passing said light component-enriched effluent from the pressure zone into the outlet of the adsorber to partially repressurize the adsorber;(6) passing an additional portion of the multi-component feed gas mixture into the inlet of the adsorber to complete repressurization of the adsorber; and(7) repeating the foregoing steps to produce the heavy component-containing product stream.