| Microburners are studied theoretically and experimentally to develop a device capable of harnessing the chemical energy of hydrocarbons into thermal energy or electrical power in a manner that is comparable to high performance battery technology in terms of energy density.; A computational fluid dynamics model of a homogeneous microburner is solved to study the effects of microburner dimensions different parameters on combustion characteristics and flame stability. Large gradients in temperature and composition are observed, despite the small scales of the system. It is found that the thermal properties of the walls play a vital role in determining flame stability in these microburners, as they are responsible for the majority of the upstream heat transfer.; As a result of the difficulties that are predicted with homogeneous microcombustion, ceramic catalytic microchannel burners are fabricated. Hydrogen/air mixtures are found to be self-igniting over a wide range of equivalence ratios, and self sustaining down to the leanest limits. Propane/air mixtures are found to be self-sustaining over a wide range of compositions. Hydrogen is used to successfully ignite propane/air mixtures. The channel gap size plays a significant role in determining reaction rates as well as dominant chemistry routes.; In ceramic-based microburners, large thermal gradients are observed. In order to achieve thermal uniformity within the system, a microburner is fabricated that allows for 'tuning' of the wall thermal resistance in order to determine the requirements for obtaining thermal uniformity. CFD studies predict that the system is heat transfer limited in the inlet, while the cold inlet gasses are heated, and mass transfer limited later in the reactor, despite the small length scales of the system.; In order to demonstrate the feasibility of microburners as portable power generators, a catalytic microburner is integrated with a thermoelectric device. Electrical power is produced using either hydrogen or propane as fuels, over a range of fuel/air ratios, with total thermal efficiencies as high as ∼1%. This is the highest efficiency of an integrated microburner-thermoelectric device ever reported in the literature. |
