Are the molecular sieves used in PSA and VPSA oxygen generators the same

The principles of oxygen production in PSA and VPSA are almost identical, with the main difference being in the air source. VPSA uses blowers and vacuum pumps, while PSA uses air compressors; the other components are quite similar. However, the core component they use—the molecular sieve is different. Typically, PSA oxygen generators use sodium-based molecular sieves, while VPSA uses lithium-based molecular sieves. The main differences are as follows:

• The sodium molecular sieve used in PSA oxygen generators can adsorb and desorb at higher pressures. Lithium molecular sieves can desorb at lower pressures and under vacuum, making them suitable for large-scale oxygen production with low energy consumption.

• Lithium is a relatively rare metal with a high production cost, making it suitable for projects with a larger initial investment, as it can reduce long-term operational costs to some extent. Sodium is more common, so the production cost of sodium molecular sieves is relatively low. Although its adsorption efficiency for air is inferior to that of lithium molecular sieves, its stability is superior.

• Lithium molecular sieves require strict temperature and pressure control during operation, demanding stringent operating conditions and precise control capabilities from the system. This includes high-precision sensors, reliable control systems, and real-time monitoring mechanisms. Sodium molecular sieves require less stringent operating conditions, are easier to control, and have lower system requirements, making them more suitable for widespread use in industrial production.

Objectively speaking, using lithium molecular sieves in VPSA oxygen generators and sodium molecular sieves in PSA oxygen generators are both reasonable choices. If the two were swapped, normal production could still occur; however, it would not maximize the capabilities of the oxygen production system or maximize customer profits. Therefore, the choice of molecular sieve is not fixed and should be determined based on actual application needs, cost budget, and operating conditions.