How Oxygen PSA Generators Work

Air contains 21% oxygen, 78% nitrogen, 0.9% argon and 0.1% other trace gases. An Oxair oxygen generator separates this oxygen from compressed air through a unique process called Pressure Swing Adsorption. (PSA).


The PSA process for generating enriched oxygen gas from ambient air utilises the ability of a synthetic zeolite molecular sieve to absorb mainly nitrogen. While nitrogen concentrates in the pore system of the zeolite, oxygen gas is produced as a product.

Oxair’s oxygen generation plants use two vessels filled with zeolite molecular sieve as adsorbers. As compressed air passes up through one of the adsorbers, the molecular sieve selectively adsorbs the nitrogen. This then allows the remaining oxygen to pass up through the adsorber and exit as a product gas. When the adsorber becomes saturated with nitrogen, the inlet airflow is switched to the second adsorber. The first adsorber is regenerated by desorbing nitrogen through depressurisation and purging it with some of the product oxygen. The cycle is then repeated and the pressure is continually swinging between a higher level at adsorption (production) and a lower level at desorption (regeneration).