Working principle of PSA pressure swing adsorption for hydrogen production

The principle of PSA is that different adsorbents have different adsorption capacity for different substances, and the same adsorbents have different adsorption capacity for the same substance with the increase of pressure, the pressure decreases the adsorption capacity decreases. Adsorption separation of gas mixture is in a fixed adsorption bed, a variety of adsorbents filled in the adsorption bed, when the converted gas (gas mixture) under a certain pressure into the adsorption tower adsorption bed, due to the different adsorption characteristics of h 2, Co, ch 4 and Co 2 in the converted gas, h 2, Co, ch 4 and Co 2 gases form adsorption enrichment zones at different positions in the adsorption column, and the strongest adsorption component (Co 2) is concentrated at the mouth of the adsorption bed, the weak adsorbed component (H2) was enriched at the outlet of the adsorption bed, and the other components were distributed in the middle of the adsorption bed.

The PSA process adopts 4-1-2 PSA process, which is composed of 4 adsorbents, 1 adsorbents feeding at the same time, 2 times equalizing pressure, normal pressure / flushing. Each adsorption tower in a cycle needs to go through adsorption, pressure drop, along with the release, reverse release, flushing, pressure rise, the final flush a total of 9 steps.