Studies on the expansion characteristics of fluidised beds with silica-based adsorbents used in protein purification

In these investigations, a detailed examination of the fluid dynamic characteristics of expanded beds containing silica-based chromatographic adsorbents has been carried out. In particular, the effects of the column accessories such as distributor design and the flow-rate on the dispersion coefficient of the adsorbent particles have been examined. The experimental data have been analysed in terms of residency time effects, fluid flow characteristics and physical properties of the adsorbent particles using several different theoretical models. In common with experience of packed-bed systems, the results confirm that the optimisation of the dynamic capacities as well as the dynamic adsorption rates of adsorbents in expanded-bed systems must take into account column design characteristics as well as the physical/chemical features of the adsorbents, if the highest productivities of expanded-bed/fluidisation procedures are to be achieved with crude feedstocks from biotechnological applications.