Simulation study of two units of pressure swing adsorption for producing oxygen and nitrogen simultaneously

Abstract

An investigation on two processes of pressure swing adsorption (PSA) to produce oxygen and nitrogen simultaneously was conducted numerically through exploiting depressurizing and purging gas of each process by each other. Each unit included two bed six step PSA process. The first unit packed with zeolite 13X for oxygen generation, and the second unit packed with carbon molecular sieve (CMS) for nitrogen generation. Three configurations were studied, two process were operated individually, depressurizing and purging gas of each process used by other unit ( no gas vented to atmosphere), and the third configuration was similar to the second configuration except purging gas of the second unit was vented to atmosphere. Configuration three produced oxygen with purity 98% and nitrogen with purity 95% together in comparing with configuration 1, and 2. Configuration 2 produced oxygen with purity over 99% while nitrogen purity dropped dramatically to be lower than its atmospheric purity (78%). Oxygen and nitrogen purity in all configuration improved with increasing the adsorption pressure.