Nitrogen PSA with intermediate pressure transfer

摘要

A process for pressure swing adsorption of oxygen from a gas mixture containing at least oxygen and nitrogen to recover an unadsorbed nitrogen enriched product from a plurality of parallel piped adsorbent beds undergoing adsorption, depressurization and repressurization wherein the improvement is conducting a pressure transfer from one bed to another from an intermediate point of the bed finishing adsorption to a point closer to the feed end of a bed that is repressurizing to improve productivity and recovery of nitrogen enriched gas in the process.