Abstract: In air separation and other gas separations employing pressure swing adsorption technology, reduced cycle times are achieved by an advantageous combination of simultaneous processing steps. The repressurization step in which the upper adsorption pressure is reached in each adsorbent bed is carried out while simultaneously withdrawing product gas from that bed. Following cocurrent depressurization steps in which released void space gas is used for pressure equalization and provide purge gas purposes, each bed, in turn, is further cocurrently depressurized, and the released gas is used for pressure equalization purposes, while the bed is simultaneously being countercurrently depressurized. This latter countercurrent depressurization is then continued to a lower desorption pressure is reached, after which the bed is partially repressurized by pressure equalization, before being further repressurized to upper adsorption pressure with simultaneous withdrawal of product as the next processing cycle is begun.

Abstract: In air separation and other gas separations employing pressure swing adsorption technology, reduced cycle times are achieved by an advantageous combination of simultaneous processing steps. The gas released upon cocurrent depressurization from higher adsorption pressure is employed simultaneously for pressure equalization and provide purge purposes. Cocurrent depressurization is also carried out at an intermediate pressure level, while countercurrent depressurization is simultaneously carried out at the opposite end of the bed being depressurized to its lower desorption pressure level.