Performance stability in rapid cycle pressure swing adsorption systems

A pressure swing adsorption process for the production of oxygen comprising

• (a) providing at least one adsorber vessel having a feed end and a product end, wherein the vessel comprises a first layer of adsorbent material adjacent the feed end and a second layer of adsorbent material disposed between the first layer and the product end, wherein the adsorbent in the first layer is selective for the adsorption of water from a mixture comprising water, oxygen, and nitrogen, the adsorbent in the second layer is selective for the adsorption of nitrogen from a mixture comprising oxygen and nitrogen, and the surface area to volume ratio of the first layer of adsorbent material is in the range of about 0.75 to about 1.8 cm−1;
• (b) introducing a pressurized feed gas comprising at least oxygen, nitrogen, and water into the feed end of the adsorber vessel, passing the gas successively through the first and second layers, adsorbing at least a portion of the water in the adsorbent material in the first layer, and adsorbing at least a portion of the nitrogen in the adsorbent material in the second layer, wherein the superficial contact time of the pressurized feed gas in the first layer is between about 0.08 and about 0.50 sec;
• and
• (c) withdrawing a product gas enriched in oxygen from the product end of the adsorber vessel.