Pressure Swing Adsorption, or PSA, involves adsorption under relatively high pressure.

　　Pressure Swing Adsorption (PSA) is a gas separation process in which adsorption is carried out at relatively high pressure and the adsorbent is regenerated at lower pressure. This method relies on the selective adsorption of oxygen and nitrogen components in air by molecular sieves to achieve air separation and produce oxygen. When compressed air is passed through an adsorption tower packed with molecular sieves, nitrogen molecules are preferentially adsorbed, while oxygen molecules remain in the gas phase and are thus collected as oxygen.

　　The PSA process can produce oxygen with a purity of 80% to 95%, with an electricity consumption typically ranging from 0.32 kWh/Nm³ to 0.37 kWh/Nm³. The adsorption pressure is above atmospheric pressure, generally between 30 kPa and 100 kPa. The process is simple, operates at ambient temperature, features a high degree of automation, enables unmanned operation, and, in particular, offers excellent safety.

　　In the vacuum desorption process, the operating pressure of the equipment is low, and vessels and other components are not subject to pressure vessel code regulations. Pressure swing adsorption processes are classified according to the number of adsorbers into single-tower, two-tower, three-tower, and five-tower configurations. Among these, the five-tower PSA configuration is the most widely used: it employs five adsorption beds, four blowers, and two vacuum pumps, with two beds continuously undergoing adsorption and vacuum evacuation throughout the entire cycle, thereby effectively addressing the technical challenges associated with large-scale oxygen production.