PSA oxygen production employs high-quality oxygen molecular sieves as adsorbents. It operates by pressurized adsorption and atmospheric pressure desorption to separate oxygen and nitrogen in the air and extract oxygen.
The adsorbent used in PSA oxygen production is zeolite molecular sieve, which is a polar adsorbent composed of a framework of positively charged cations and negatively charged silicon-aluminum-oxygen. Although O2 and N2 are non-polar adsorbates, the influence of polar molecules in zeolite molecular sieve induces a force. Since the induction force of N2 is greater than that of O2, the adsorption capacity of zeolite molecular sieve for N2 is much higher than for O2.
When air passes through the zeolite molecular sieve, N2 is preferentially adsorbed by the zeolite molecular sieve and enriched in its micropores, while O2, except for a small amount, mostly passes through the zeolite molecular sieve to become product oxygen. As zeolite molecular sieve is a polar substance, the stronger the polarity or the easier the polarization of the molecule, the easier it is to be adsorbed. Therefore, substances in the air such as acids, bases, carbon dioxide, oxides, halogens, etc., which are highly polar molecules, naturally find it difficult to enter the product oxygen through the zeolite molecular sieve.