MODELS OF PORE DIFFUSION IN POROUS CATALYSTS

Four different pore diffusion models are fitted to iso-baric counter-d iffusion fluxes measured in technical catalysts by a Wicke-Kallenbach cell over a 30-fold pressure range with different gas pairs. The model s differ significantly with respect to predictive capabilities and com putational requirements. Of the models studied, only the cross-linked pore model (Johnson and Stewart, 1965; Feng and Stewart, 1973), can pr edict diffusion fluxes reliably solely from pore size distribution. Th e study emphasizes the versatility and accuracy of the cross-linked po re model. (C) 1998 Elsevier Science Ltd. All rights reserved.