Mesoscale Power Generator

Batteries have at most 2% of the energy density of hydrocarbon fuels, but scaled-down electrical generators for portable power applications employing internal combustion engines have been unsuccessful due to the difficulty of minimizing heat and friction losses. An alternative approach that does not require moving parts is single-chamber solid oxide fuel cells (SCFCs) with thermal transpiration (gas pumping in a nanoporous medium with an applied temperature gradient) to supply the reactants to the SCFCs and maintain sufficiently high temperature for their operation.

With this concept, catalytic combustion and thermal transpiration membrane modelling was studied individuallly and integrated together for a airbreathing cylindrical chamber. It was designed in which along the cylinder employed a glass microfiber filter as a transpiration membrane. Aluminum structure were designed to provide nearly uniform temperature on inside surface of the membranes. Platinum mesh was used as a catalyst for rich butane-air combustion, the products of which supply the SCFCs. It was found that the temperature and flow rates are appropriate for SCFC operation and equivalence ratio can be varied from 1.5 to 18.9. The system is able to provide self-sustaining power generation without moving parts using hydrocarbon fuel.