Catalyst optimization in a catalytic flow reversal reactor for lean methane combustion

This paper describes a detailed catalyst configuration study for a catalytic flow reversal reactor for lean methane combustion using computational modelling. The design is based on the use of a platinum group metals catalyst in the form of a washcoated monolith. A small-scale pilot plant reactor is used as the basis for the study. The computational model is based on the fundamental conservation equations of mass and energy that are solved using the finite element method with commercial software. Extensive model validation is performed using experimental data previously obtained on the pilot plant system. It is found that catalyst activity and length of the reaction section play key roles in the stable operation and performance of the system. For methane feed concentrations above about 0.5% by volume, the catalyst activity plays a relatively small role. For concentrations down to about 0.2% both the catalyst activity and reactor length become increasingly important. The complete transient history of the reactor also plays an important role in determining whether or not a stable stationary state can be achieved for a given set of inlet conditions. Computational modelling is shown to be an extremely valuable tool for the design of the reactor system.