PSA nitrogen gas generators utilize pressure swing adsorption technology for nitrogen production. This technology works much differently than membrane technology in that it uses a carbon molecular sieve (CMS) made up of a special material the size of a grain of rice. This porous material is packed into cylindrical vessels, which is then filled with compressed air. Under pressure, adsorption takes place – the CMS material holds onto, or adsorbs the oxygen in the compressed air.
Meanwhile, the larger nitrogen molecules proceed past the CMS and into a nitrogen receiver. Then, pressure is released and the CMS material releases the oxygen through a vent into the atmosphere. The cycle repeats process in a second cylinder while the first cylinder is releasing the oxygen . The changing from cylinder to cylinder is called “pressure swing.”