Mass transfer kinetics in pressure swing adsorption

Many mass transfer kinetic models are used to study varying pressure steps of a pressure swing adsorption (PSA) cycle. namely pressurization and blowd own steps. It is shown that the choice of an appropriate model to account f or intra-particle diffusional limitations is essential to simulate accurate ly PSA processes. It has been demonstrated that, besides mathematical appro ximations (parabolic profile within the particle), a very important factor that can affect simulation results remarkably is the correctness of the mas s transfer kinetic model when regarded as being a mass balance for the adso rbent particle. In fact, neglecting intra-particle gas phase leads to erron eous simulations. Some models widely used in the literature, such as the cl assic linear driving force (LDF) and the solid diffusion models prove inade quate. It is recommended to use pore diffusion model as well as a new versi on of the solid diffusion model to get reliable predictions. (C) 2000 Elsev ier Science B.V. All rights reserved.