A generalized shrinking core model applied to batch adsorption

Abstract

A two resistance mass transfer model for batch adsorption process has been developed which includes a film mass transfer coefficient and an internal effective diffusivity that controls the internal mass transport process based on the pore diffusion mechanism. This model is based on shrinking core formulation for catalytic reaction. The model proposed here is more generalized, can accommodate wide range of initial adsorbate concentration in feed and the nature of the isotherm. The model is solved numerically and optimized using nonlinear parameter estimation technique in order to match with the experimental kinetic data available in the literature [AIChE J. 39 (1993) 2027; AIChE J. 30 (1984) 692; Adsorp. Sci. Technol. 4 (1987) 58]. In this procedure the process parameters, i.e. the external mass transfer coefficient and internal effective diffusivity are determined for a particular system. Using the estimated parameters, a parametric study has been carried out to observe the effects of initial adsorbate concentration, particle size of adsorbent, mass of adsorbent, etc. on the system kinetics.