Oxidative steam reforming of light hydrocarbons in a catalytic microchannel reactor

Oxidative steam reforming (OSR) reaction of light hydrocarbons (methane and propane) is investigated under exhaust gas reforming (EGR) conditions in a catalytic heat-exchange integrated microchannel by computational and experimental techniques. OSR of propane is investigated by computer-based modeling and simulation studies to demonstrate the effects of different exhaust gas compositions from diesel and gasoline internal combustion engines (ICEs) by parametric variation of the amounts of propane and steam injected into the EGR feed and of the total feed flow rate. Steady-state simulations conducted using computational fluid dynamics (CFD) show that effective heat transfer and uniform temperature distribution can be obtained in the microchannel configuration even at low gas hourly space velocities (GHSVs). Higher hydrogen and carbon monoxide yields are possible by injecting more propane and steam into the feed. Increasing total feed flow rate, hence the GHSV improves axial heat distribution, but can lead to reduction in the hydrogen and carbon monoxide yields due to insufficient contact time. In the experimental part of the work, microfluidic EGR process is observed via OSR of methane over three different Pt- and Rh-based catalyst configurations. For each catalyst configuration, parametric study of methane OSR is conducted in order to observe the effects of feed compositions (molar steam-to-carbon and oxygen-to-carbon ratios) and temperature on methane conversion and on product distribution. The results show that methane conversion is enhanced with the increase in temperature and in the amounts of oxygen and water in the feed stream. The catalyst combination involving 2wt % Rh/alumina coated catalyst only is found to exhibit the best performance in terms of increased methane conversion, and hydrogen and carbon monoxide compositions.