Adsorptive process for producing two gas streams from a gas mixture

Claim 1

A pressure swing adsorption process for recovery of two gas products at high recovery and high purity from a feed gas stream containing said products wherein a first gas product is a less strongly adsorbed component and a second gas product is a more strongly adsorbed component, comprising: (a) introducing a feed gas stream at elevated pressure containing said less strongly adsorbed component and said more strongly adsorbed component into one of a plurality of parallel adsorptive beds filled with an adsorbent selective for said more strongly adsorbed component, so as to retain said more strongly adsorbed component on said adsorbent and allow the less strongly adsorbed component to pass through said bed for recovery as said first gas product at high recovery and high purity; (b) terminating the introduction of said feed gas stream into said bed before said more strongly adsorbed component breaks through the downstream end of said bed and depressurizing said bed to approximately ambient pressure to remove less strongly adsorbed component from said bed and recycling the resulting depressurization effluent to said feed gas stream; (c) passing a low pressure purge gas stream of more strongly adsorbed component through said bed to remove any residual less strongly adsorbed component from said bed and recycling the resulting effluent from said purged bed to the feed gas stream; (d) evacuating said bed to a subambient pressure to recover more strongly adsorbed component as said second gas product at high recovery and high purity, and (e) repressurizing said bed with less strongly adsorbed component to approximately the pressure of the feed gas stream, wherein the steps (a) through (e) are performed on said plurality of beds to result in a continuous process.