PRESSURE SWING ADSORPTION REACTORS - SIMULATION OF 3-STEP ONE-BED PROCESS

A three-step (feed, delay, and purge), one-column pressure swing adsor ption reactor has been analyzed. An equilibrium model taking into acco unt species mass balances, overall mass balance, momentum balance, rea ction rate, and nonlinear multicomponent adsorption equilibrium isothe rms was derived to describe the PSA reactor process. Numerical solutio n of model equations was obtained by using the method of orthogonal co llocation on finite elements, and simulation results showed that 10-20 % higher conversion than reaction equilibrium conversion in afixed-bed reactor could be obtained from the PSA reactor for a reversible react ion A reversible B + C, such as dehydrogenation of ethane to ethylene and hydrogen on cadmium-exchanged zeolites, where only product B was a ssumed to be adsorbed. When both reactant A and product B are adsorbed , 10% higher conversion over the reaction equilibrium limit was observ ed for pure reactant feed. The effects of system and operating paramet ers on the process performance of the PSA reactor have been studied, a s well as the bed dynamics of the PSA reactor at the cyclic steady sta te.