Single channel and heat recirculation catalytic microburners: An experimental and computational fluid dynamics study

The stability of C3H8/air mixtures on Pt in single channel and heat recirculation catalytic microburners is compared experimentally using a microreactor capable of operating in both modes. The stability is further studied using computational fluid dynamics simulations, where the material properties of the burner can be systematically changed. It is shown through both experiments and simulation that catalytic heat recirculation burners have similar stability to single channel burners in the limit of highly conductive walls. In contrast, for low conductivity walls, heat recirculation proves to be effective at increasing combustion stability relative to single channel burners. Increasing the flow rate significantly extends the fuel lean extinction limit at low inlet velocities. Finally, optimal catalyst placement in heat recirculating burners is discussed.