US Patent 6902602 Gas separation by combined pressure swing and displacement purge

The present disclosure relates to systems and processes for adsorptive gas separations where a first gas mixture including components A and B is to be separated so that a first product of the separation is enriched in component A, while component B is mixed with a third gas component C contained in a displacement purge stream to form a second gas mixture including components B and C, and with provision to prevent cross contamination of component C into the first product containing component A, or of component A into the second gas mixture containing component C. The invention may be applied to hydrogen (component A) enrichment from syngas mixtures, where dilute carbon dioxide (component B) is to be rejected such as directly to the atmosphere, and with preferably nitrogen-enriched air as the displacement purge stream containing residual oxygen (component C).