Pressure swing adsorption: An experimental study of diffusion‐induced separation

Abstract

AbstractGas separation based on differences in intraparticle diffusion rates was achieved by four‐step pressure swing adsorption (PSA) process. The application studied was the separation of nitrogen from air using molecular sieve type RS‐10. Systematic PSA experiments were conducted in bench‐scale equipment to study several variables, including duration of steps of the cycle, flow rates, pressure ratio, subatmospheric blowdown and purge, and column geometry.The test results were compared with predictions of a mathematical model (Shin and Knaebel, 1987). In all cases, the trends of product purity and net recovery of both theory and experiment were in close agreement. Since the theory accurately portrays the overall behavior of the process, the transport mechanisms embodied in the theory may provide insight into diffusion‐induced separation by PSA. In addition, by reviewing the results of the parametric studies of the variables, it has been possible to gain an intuitive understanding of the relations between factors that affect each step, and hence overall performance.