The role of effectiveness factor on the modeling of methanol steam reforming over CuO/ZnO/Al2O3 catalyst in a multi-tubular reactor

Abstract

A pseudo-homogeneous model for the methanol steam reforming process was developed based on reaction kinetics over a CuO/ZnO/Al 2 O 3 catalyst and non-adiabatic heat and mass transfer performances in a co-current packed-bed reactor. A Thiele modulus method and an intraparticle distribution method were applied for predicting the effectiveness factors for main reactions and providing insights into the diffusion-reaction process in a cylindrical catalyst pellet. The results of both methods are validated and show good agreements with the experimental data, but the intraparticle distribution method provides better predictions. Results indicate that increases in catalyst size and bulk fluid temperature amplify the impact of intraparticle diffusion limitations, showing a decrease in effectiveness factors. To satisfy the requirements of a high temperature polymer electrolyte membrane fuel cell stack, the optimized operating conditions, which bring the methanol and CO concentrations to less than 1 % vol in the reformate stream, are determined based on the simulation results. • One-dimensional pseudo-homogeneous model of a packed-bed methanol steam reformer. • Two methods to obtain approximate solutions of the catalytic effectiveness factor. • Validation of reaction kinetics and effectiveness factors with experimental data. • Effects of main operating parameters on the intraparticle heat and mass transfer. • Optimized conditions to obtain less than 1% of CH 3 OH and CO in reformate gas.