DIFFUSION AND CONVECTION IN CHROMATOGRAPHIC PROCESSES USING PERMEABLE SUPPORTS WITH A BIDISPERSE PORE STRUCTURE

An analysis of chromatographic processes utilizing permeable particles with a bidisperse pore structure is presented. The analysis is restricted to the case of a pulse input of a linearly adsorbed tracer and is based on the assumption that the adsorbent pellets consist of equally sized microparticles with intercalating throughpores. Simultaneous diffusion and convection in the throughpores and diffusion in the microparticles are taken into account for slab-shaped and spherical pellets and expressions for the height equivalent to a theoretical plate are derived. On this basis, a criterion is developed to determine under what conditions transport limitations in purely diffusive pores influence the performance of chromatographic processes utilizing permeable particles.