(552c) Catalytic Microcombustors with Integrated Thermoelectric Elements for Portable Power Production

Recently, there has been an increase in the demand for more compact, portable electronics for applications ranging from cellular phones to military field equipment. Most of these consumer electronics are limited in size and continuous operation time by the battery. While conventional lithium ion batteries, primarily used in notebook computers, have an energy density of approximately 0.5 MJ/kg, liquefiable hydrocarbons, such as propane, have two orders of magnitude higher (40 MJ/kg) energy density [1]. This alternative energy source has sparked research efforts toward novel devices capable of micropower generation. Micropower generation devices utilizing hydrocarbons have the potential to be lighter, longer lasting, and/or less expensive than conventional bulky power sources. They could also be more environmentally benign since the system could be simply refilled instead of discarded. In this study, catalytic microcombustors are integrated with thermoelectrics to produce electricity. The devices are found to be robust, easy to start up, and able to support complete combustion over a range of fuels (e.g., C3H8/air and H2/air systems) at different flowrates. Various materials of construction for the microcombustors are investigated in order to yield good temperature uniformity, which is shown to increase electrical power output and efficiency. Factors that impede optimal integration of the thermoelectric module, such as compressive force and lack of heat recirculation, are investigated. Electrical power generation from catalytic microcombustion with a thermal efficiency up to ~0.8% is measured [2]. Parameters affecting energy efficiency are also discussed.

1. Sitzki, L., K. Borer, E. Schuster, P.D. Ronney, and S. Wussow. Combustion in Microscale Heat-Recirculating Burners. in The Third Asia-Pacific Conference on Combustion. 2001. Seoul, Korea.

2. Federici, J.A., D.G. Norton, E.D. Wetzel, and D.G. Vlachos, Catalytic Microcombustors with Integration of Thermoelectric Elements for Portable Power Production. Journal of Power Sources, 2006. Submitted.