Patent ID: 6544318
Filing Date: 2003-04-08
Classification: B01D,Y10S

Abstract:
In a cyclic pressure swing adsorption process for the recovery of oxygen from a feed gas comprising oxygen, nitrogen, and argon, a combined forward flow stage which comprises:(a) passing the feed gas into a first adsorption zone containing an adsorbent selective for the adsorption of nitrogen over oxygen and argon, and withdrawing therefrom a nitrogen-depleted intermediate gas; (b) passing the nitrogen-depleted intermediate gas into a second adsorption zone containing an adsorbent which is selective for the adsorption of nitrogen over argon and selective for the adsorption of argon over oxygen; (c) withdrawing an oxygen-enriched product gas from the second adsorption zone; and (d) terminating the passing of feed gas into the first adsorption zone and withdrawing an oxygen-enriched depressurization gas from the second adsorption zone in the same flow direction as (c); wherein nitrogen breakthrough from the first adsorption zone occurs and nitrogen is adsorbed in the second adsorption zone after nitrogen breakthrough.