An improved pressure swing adsorption process enables the more readily adsorbable component of a feed gas to be economically recovered, e.g. nitrogen from air. The more readily absorbable component is used as copurge at upper adsorption pressure, and less readily adsorbable component is used for countercurrent purge at subatmospheric desorption pressure and for initial repressurization in a countercurrent backfilling step.
展开▼