PRESSURE SWING ADSORPTION - A THEORETICAL-STUDY OF DIFFUSION-INDUCED SEPARATIONS

This report examines gas separation by a pressure swing adsorption (PSA) process that exploits differences in intraparticle rates of diffusion, rather than differences in adsorption isotherms. Film and intraparticle diffusion resistances are taken into account, but only the latter is examined closely. Each step of a four-step cycle is incorporated, and concentration profiles within the particles and along the column axis are predicted. Several critical PSA operating conditions, including step times, velocities, and pressures are studied in the context of separation of nitrogen from air with zeolite 4A.