Choice and order of cycle stages
Purification of gases through the PSA(Pressure Swing Adsorption) process - fundamentals and cycles at pressure

An adsorber, having been regenerated and recompressed, is ready to restart a PSA cycle with an adsorption phase at the high pressure of the cycle. This will preferably be fed by the gas to be treated which is the least rich in the gas to be adsorbed. In this way, in the presence of several different feedstocks, successive adsorption stages can be implemented, possibly including a recovery stage to improve the unit's performance. Generally speaking, it should be pointed out that (adsorption) fronts of higher concentration tend to move faster within the adsorber than fronts of lower concentration, which sometimes enables optimization of the adsorption volume installed by catching up the front of lower concentration with a front of higher concentration. In this way, the saturation zone is advantageously "constant" in concentration and at its maximum upstream of the mass transfer zone at the...