In the process of nitrogen production, oxygen production, purification and recovery, gas drying and so on, the pressure swing adsorption technology is widely used and widely used.

The basic principle of pressure swing adsorption is to use the adsorbent to have different adsorption capacity under different pressures, and to selectively adsorb the components of the separated gas mixture. Under the condition of selective adsorption of adsorbent, one or some component of the feed gas is pressurized and adsorbed, and then removed after decompression, so as to separate the mixed gas, At the same time, the adsorbent is regenerated. Therefore, two or more adsorption towers are generally used to alternately change the pressure of each adsorption tower, and the continuous separation of gas mixture can be realized. Because the adsorption and desorption process is realized by pressure change, this process is called pressure swing adsorption (PSA).