High Quality Content by WIKIPEDIA articles! Vacuum swing adsorption (VSA) is a non-cryogenic gas separation technology. Using special solids, or absorbents, VSA segregates certain gases from a gaseous mixture under minimal pressure according to the species' molecular characteristics and affinity for the absorbents. These absorbents (e.g., zeolites) form a molecular sieve and preferentially absorb the target gas species at near ambient pressure. The process then swings to a vacuum to regenerate the absorbent material.