(398e) Dynamics of Membrane Steam Reformer for Automotive Fuel Cell Applications

A dynamic model for plate type membrane reformer for steam reforming of methane for automotive applications is presented. Endothermic steam reforming reaction is coupled with burner in which exothermic catalytic reaction of combustion of methane takes place. The reactor contains three channels. Hydrogen is removed simultaneously by membrane. Steam reformer is modeled as a pseudo homogeneous reactor and burner is modeled plate type monolith reactor. Pressure inside burner and steam reformer is assumed to be constant. Gas is assumed to be an ideal gas. Concentration and temperature dependence of viscosity and diffusivity of gas mixture is incorporated in both burner and reformer model for better accuracy. Heat transfer and mass transfer coefficients for burner are modeled using suitable correlations. Resulting 19 partial differential equations (with time domain) are discretized spatially using spline collocation on finite elements and solved numerically. Both co-current and counter-current mode of flow arrangement for sweep gas is considered. Based on simulation results, effect of different operating parameters like methane/steam ratio, fuel concentration, inlet reactant temperatures and inlet gas velocities on hydrogen recovery yield and methane conversion was analysed.