Provided is an oxygen concentration device which, as an oxygen concentration device having a reduced difference in flow rates of gas which flows through a pressure equalization valve of a pressure equalization path during a purge step and a pressure equalization step, is provided at at least one end side of the pressure equalization valve with a pressure control member having a difference in pressure loss due to the direction of gas flow so that pressure loss of the gas which flows through the pressure equalization path in one direction becomes nearly equal to that of the gas which flows therethrough in the opposite direction.

A structured adsorbent assembly is described, which is usefully employed for pressure swing adsorption (PSA) processing of ambient air to generate high purity oxygen. The structured adsorbent assembly in various implementations may include cellulosic carbon molecular sieve fibers formed by spinning of precursor cellulose followed by pyrolysis of the spun fibers, as an argon-selective adsorbent, or AgX zeolite contained on and/or in polymeric fibers, as an argon-selective adsorbent, and such argon-selective adsorbents may be in combination with nitrogen-selective adsorbent such as LiX zeolite contained on and/or in polymeric fibers. The structured adsorbent assembly may be employed in PSA systems and processes to achieve highly efficient and economic generation of high purity oxygen for applications such as distributed gasification power generation.

Described are processes and equipment that are useful to produce purified oxygen gas using a cryogenic adsorption bed to remove impurities such as nitrogen-containing impurities (e.g., nitrogen (N.sub.2), nitrogen oxides, ammonia, amines), water, carbon dioxide, carbon monoxide, hydrocarbons, among others, from oxygen gas.