(58e) Thermally Efficient Short-Contact Time Catalytic Plate Reactor: Detailed Multi-Step Mathematical Model and Parametric Study for Methane Steam Reforming

Due to its high thermal efficiency and low pressure drop, short-contact time Catalytic Plate Reactors (CPRs) have received more attention in recent years for small scale stationary and on-board fuel cell power generators. This study focuses on detailed two-dimensional steady state modeling and simulation of a CPR for the endothermic catalytic Steam Methane Reforming (SMR) on one side of a metal plate and the exothermic methane combustion on the other. The reforming side of the plate was considered to be coated with a nickel-alumina (Ni-Al₂O₃) catalyst and the combustion side with a platinum-alumina (Pt-Al₂O₃). A multi-step surface microkinetic model was adopted to simulate the catalytic SMR process; whereas, a lumped surface kinetic model, which is based on a microkinetic model, was used to simulate the catalytic combustion process. To simulate the gas-phase methane combustion, a one-step homogeneous kinetic model was adopted. Two Langmuir-Hinshelwood Hougen-Watson (LHHW) type kinetic models of the SMR were also implemented on the reforming side for a comparative study. Simulation results obtained using the LHHW type kinetic models and the multi-step surface microkinetic model of methane steam reforming were compared with experimental results in terms of the methane conversion, and the carbon monoxide selectivity, S_CO. The results obtained using the microkinetic model, have showed excellent representation of the experimental data compared to the LHHW models. Base case study and parameter sensitivity study were performed using the microkinetic model, and important criterion for the CPR performance are identified. Flow arrangement between the two channels, reforming catalyst thickness, space velocities and metal plate thickness are found to have major influence on methane conversion and thermal profiles of the CPR.