Patent ID: 6048384
Filing Date: 2000-04-11
Classification: B01D,Y02C

Abstract:
A pressure swing adsorption (PSA) method for extracting a more preferred gas from a mixture of said more preferred gas and a less preferred gas, said method employing an adsorbent bed within an enclosure which, on an equilibrium basis, exhibits a selective adsorption preference for said less preferred gas, said method comprising the steps of:a) pressurizing said adsorbent bed to a high pressure with a feed of said mixture to enable said adsorbent bed to adsorb said less preferred gas while simultaneously counter-currently feeding gas obtained from a product tank containing more preferred gas;b) extracting from said bed at said high bed pressure, a flow of said more preferred gas and storing at least some of said flow of more preferred gas in said product tank;c) desorbing said less preferred gas from said adsorbent bed by feeding void gas in said enclosure to a void gas storage tank, while simultaneously desorbing said less preferred gas from said adsorbent bed by venting said adsorbent bed to a first low pressure region;d) terminating feeding of said void gas to said void gas storage tank;e) further desorbing said less preferred gas from said adsorbent bed by venting said adsorbent bed to a second low pressure region that is lower than said first low pressure region;f) purging said adsorbent bed by feeding to said adsorbent bed a portion of said void gas from said void gas storage tank while venting said adsorbent bed;g) pressurizing said adsorbent bed to an intermediate pressure with a flow of equalization gas from a second adsorbent bed; and repeating steps a-g until a requirement for said more preferred gas is satisfied.