Simulation of nonisothermal pressure swing adsorption

Abstract

Nonisothermal pressure swing adsorption is simulated by numerical calculation, by accounting for mass transfer as well as heat transfer in the column, where linear driving force for adsorption rate and linear isotherm were assumed, 40 cycles of PSA operation from start-up are iterated in the computer as a case study of air drying by activated alumina. Assuming that volumetric ratio of purge to feed is 2, steady mode is observed after 30 cycles and almost constant distribution of amount adsorbed in the bed is found to be established. Condition for isothermal, nonisothermal or adiabatic assumption can be determined by this simulation in terms of column diameter. Bed length, cycle time and purge to feed ratio have significant effects on product concentration in the simulations. Further, optimizations are discussed as for the relation between column length and purge-to-feed ratio and as for cycle time in the case of air drying by silica gel. © 1983, The Society of Chemical Engineers, Japan. All rights reserved.