High Quality Content by WIKIPEDIA articles! Pressure swing adsorption (PSA) is a technology used to separate some gas species from a mixture of gases under pressure according to the species` molecular characteristics and affinity for an adsorbent material. It operates at near-ambient temperatures and so differs from cryogenic distillation techniques of gas separation. Special adsorptive materials (e.g., zeolites) are used as a molecular sieve, preferentially adsorbing the target gas species at high pressure. The process then swings to low pressure to desorb the adsorbent material.