Mathematical Modeling of Platinum and Chlorine Distributions within Pt-Sn/Al2O3 Catalyst Prepared by Impregnation


Petrochemical Research and Technology Company, National Petrochemical Company, No. 27, Sarv Alley, Shirazi-south, Mollasadra, P.O. Box 14358-84711, Tehran, Iran


A mathematical model for the impregnation step in the preparation of supported catalysts was developed. The kinetic parameters required for model solution were obtained by considering reversible competitive adsorption of ions on the same surface sites. The effect of pH of impregnation solution and impregnation time, as two critical operating parameters, was investigated and their influence on radial distribution was evaluated. The model was applied to Pt-Sn/Al2O3 catalyst in the presence of HCl. The experimental data required for model solution were obtained from impregnation tests performed in a tubular fixed-bed reactor with external circulation for impregnation solution; similar to configurations used in industrial cases. Kinetic parameter values obtained in the present modeling were compared with those reported in literature for similar cases. The order of magnitude for the present results is in acceptable range. As the distribution of active metal in supported catalyst plays an important role in its performance, this model is an invaluable tool by which such distributions can be predicted.