Abstract: Oxygen adsorbent for adsorbing oxygen from a mixed gas containing oxygen which comprises Na-A type zeolite containing iron with a valence of at least 2 or Na-A type zeolite in which a portion of Na is substituted with K and also contains iron. A process for the separation of oxygen from a mixed gas containing it by contacting the gas with the oxygen adsorbent at a low temperature to adsorb oxygen selectively.

Abstract: The invention relates to a process and apparatus for separating mixed gas by adsorption in which adsorption and desorption steps are repeatedly carried out in a plurality of adsorption towers in staggered timings.The invention is characterized in that upon commencement of the desorption step, mixed gas having a low adsorbate constituent gas concentration which is delivered in the initial part of a pressure-reducing period (a primary pressure-reducing period) in an adsorption tower which has completed adsorption, is fed into an adsorption tower which has finished pressure-reduction to scavenge and desorb the adsorbate constituent gas adsorbed by an adsorbent, whereby enhancement of a yield of an unadsorbate gas can be achieved as compared to scavenging desorption making use of a part of an unadsorbate gas delivered during an adsorption step.