Continuous chromatography using a liquid-solid circulating fluidized bed (LSCFB) is an efficient and eco-friendly system used for the separation and purification of biomolecules and radioactive waste. It combines continuous counter-current adsorption and simultaneous regeneration of solids. Here, we developed a mathematical model to study the performance of these counter-current adsorbers using MATLAB (TM) which is a fundamental tool for scale up. This model predicts the adsorption zone length and height equivalent to theoretical plates (HETPs). In addition, this work also illustrates the comparative performance studies of adsorption in a conventional packed bed, expanded bed and LSCFB in terms of HETP values. At lower velocities such as 0.35 cm/s, HETPs of the LSCFB, packed bed, expanded bed are 5, 12, 18 cm, respectively. (c) 2007 Elsevier Ltd. All rights reserved.