High-Pressure Methane Combustion over a Perovskyte Catalyst

Catalytic combustion has been extensively studied as an alternative route to homogeneous combustion for power generation systems, in particular for gas turbines. Despite the great interest, very little work has been devoted to high-pressure catalytic combustion, i.e., under conditions more relevant for gas turbines. In this work, the effect of pressure on the catalytic combustion of methane on a perovskite-based monolith is investigated both experimentally and numerically. Results show that methane can be ignited by increasing the operating pressure, and this behavior can be reproduced qualitatively and quantitatively by simulating the monolith using simple overall homogeneous and heterogeneous reaction rates. Moreover, numerical results show that only the coupling between catalytic and homogeneous reactions allows correct prediction of methane conversion. As the operating pressure increases, the catalytic reaction is activated, thus behaving as a pilot for sustaining the homogeneous reaction that allows it to overcome the mass transport limitations at the catalytic surface.