Importance of intraparticle convection in the performance of chromatographic processes

Abstract Large-pore materials are used in separation engineering as high-performance liquid chromatographic packings and adsorbents; however, they find also many applications in reaction engineering as catalyst supports and ceramic membrane reactors and in biotechnology as supports for mammalian cell cultures or biomass growth. In these large-pore materials, mass transport by intraparticle forced convection should be considered in process analysis. A brief historical survey of research work concerned with intraparticle forced convection is given, showing that the concept to be retained is that of effective diffusivity augmented by convection. The behaviour of the height equivalent to a theoretical plate as a function of bed superficial velocity is explained on the basis of the above concept. Analogies between slab and spherical particle geometries are discussed.