2. Pressure swing adsorption separation processes

In a pressure swing adsorption (PSA) separation process, the adsorbents are regenerated by reducing the total pressure. As liquid pressure is difficult to modify, PSA is only used for gas separation.

Pressure swing adsorption (PSA) processes really came into their own in the 1950s with the filing of the French patent by Guérin de Montgareuil and Dominé of Air Liquide and, a little later, the American patent by Skarstrom of Esso Research & Engineering, although the basic concepts were already known from earlier work. Air Liquide's invention also introduced vacuum regeneration for the first time, the basis of VSA (Vacuum Swing Adsorption) processes.