Effective dispersion model for flow-through catalytic membrane reactors combining axial dispersion and pore size distribution

In a flow-through catalytic membrane reactor, catalyst is immobilized in the pores of a membrane, which is convectively passed by the reaction mixture, allowing for high catalytic activity and a potentially narrow residence time distribution (RTD). As the membrane geometry prevents measurement of a meaningful RTD, a residence time distribution model is introduced, which accounts for deviations from ideal plug flow behavior induced by a non-ideal pore size distribution and by axial molecular diffusion. Both effects are combined to an effective dispersion model with a single dimensionless parameter, which is a function of pore geometry, axial velocity and molecular diffusion coefficient. As a result of the developed model, recommendations for optimum reactor operation are given. (C) 2009 Elsevier Ltd. All rights reserved.