Methane catalytic combustion under pressure

This work focuses on the thermal management of a monolithic reactor for catalytic combustion of methane at pressure relevant to gas turbine applications. The role of operating pressure on methane conversion, temperature profiles, and relevance of homogeneous reaction with respect to heterogeneous reaction is investigated both experimentally and numerically.Experiments of self-sustained methane combustion over a 20 wt% LaMnO3/La-γAl2O3 monolith are performed in a lab-scale test rig with operating pressure varying in the range of 1–12 bar.A Computational Fluid Dynamics (CFD) model simulating a 10 × 10 channel configuration is also developed to carry out a parameter investigation. Numerical results have allowed the identification of a reactor configuration in which only the outer perimeter channels of the monolith are coated by the catalyst, thus activating methane reaction. In the central region, that is not catalyst-coated, methane conversion by homogeneous reaction is made possible by the radial heat transfer from the external catalytic channels through the monolith walls.

Graphical abstractThe activation of homogeneous reaction favored by increasing pressure allows the identification of an optimal reactor configuration in which only the external channels of the monolith are coated by the catalyst, and used for gas phase reaction light-off in the internal channels.Figure optionsDownload full-size imageDownload high-quality image (134 K)Download as PowerPoint slideHighlights► Methane catalytic combustion is studied at pressure varying in the range of 1–12 bar. ► Experiments are performed over a 20 wt% LaMnO3/La-γAl2O3 lab-scale monolith. ► A CFD model is developed to simulate interactions among the channels of the monolith. ► At high pressure, the catalyst simply behaves as a pilot for homogeneous combustion. ► A novel reactor configuration that minimizes the catalyst load is proposed.