PRESSURE SWING ADSORPTION PROCESS

A pressure swing adsorption process for the selective adsorption of at least one gaseous component from a gaseous mixture and an apparatus for performing the process wherein the gaseous mixture is conducted in cyclic alternation through at least three adsorbers and each adsorber is subdivided into two serially connected adsorber sections. The feed gas mixture is passed, during an adsorption phase, through respectively two series-connected adsorber sections. After termination of at least one cocurrent expansion phase, the adsorber sections are isolated from each other, and the first adsorber section, i.e., first traversed by the feed gas mixture, is further expanded while the second adsorber section is maintained at a higher pressure. Thereafter, the second adsorber section can be expanded countercurrently and thus-withdrawn countercurrent expansion gas can be utilized for purging the first adsorber section.