OPTIMIZATION OF PRESSURE SWING ADSORPTION SYSTEMS - THE EFFECT OF MASS-TRANSFER DURING THE BLOWDOWN STEP

Three systems of trace separation are used as case studies to investig ate the effect of mass transfer during the blowdown step. The systems are simulated from start (clean columns) to cyclic steady state with t he desorption step period equal to the adsorption step period as a bas e case. There is no difference between the case where mass transfer is accounted for and the case where the frozen solid condition is assume d. However, in the context of optimal operation there is a significant effect for some combinations of the desorption time period and the bl owdown time period, but this effect depends on the specific system and the specification of the product purity. There is also a possible eff ect when the repressurization step is performed with product instead o f feed.