A CFD Model for Methane Autothermal Reforming on Ru/γ-Al2O3 Catalyst

Abstract

Hydrogen is the preferred fuel for fuel cells due to high reactivity for electrochemical reaction at anode. In the present study, a three dimensional CFD (Computational Fluid Dynamics) code was developed and validated to simulate the performance of a catalytic monolith fuel processor used for hydrogen generation. Methane autothermal reforming on 5% Ru/γ-Al2O3 catalyst was selected as the reaction mechanism. Ruthenium catalyst is a suitable catalyst for low temperature catalytic partial oxidation (LTCPO) process. This catalyst has good reforming activity and high hydrogen yield is obtained for ruthenium/γ-alumina. This catalyst also demonstrated to be stable within the investigation time. The computational domain of the simulations was selected to be the catalytic section of the reformer. The results provided an adequate match to the experimental data from literature with respect to the outlet and maximum reactor temperature and also distribution of the products. The reactor performance was thereafter studied by numerically revealing the effects of variations of O2/C and S/C feed molar ratios, and feed temperature on the profiles of temperature and species concentrations. Moreover, effects of using air instead of pure oxygen were also investigated. It was concluded that at higher O2/C and S/C feed molar ratios and also at higher feed gas temperature, more hydrogen will be achieved at the reactor outlet, which is very suitable for fuel cell applications.