Pressure swing adsorption process

摘要

A pressure swing adsorption process which includes switching a plurality of adsorption columns packed with an adsorbent successively to an adsorption step, a pressure equalization step, an evacuation step, a vacuum purge step, a pressure equalization step and a repressurization step to allow a more strongly adsorbable component gas contained in a gaseous mixture to be adsorbed on the adsorbent and to separate a less strongly adsorbable component gas. The process further includes compressing the thus separated less strongly adsorbable component gas by a product gas compressor to supply it as a product gas. An adsorption column having completed the adsorption step and another adsorption column having completed the vacuum purge step are allowed to communicate to each other on product discharge sides and on raw material supply sides respectively in the pressure equalization step, to recover the product gas under gradual increase of gas flow rate on the raw material supply side and also to evacuate the adsorption column having completed the adsoroption step.