Thermally self-sustaining tubular SOFC power generator with no moving parts

Hydrocarbon fuels is roughly 50 times higher energy density compared to commercial batteries. However, scaling down electrical power generators for portable devices have been far from successful due to the difficulties of minimizing heat and friction losses. Hence, an alternate solution without moving parts incorporating a micro-tubular solid oxide fuel cell (mT-SOFC), thermal transpiration (gas pumping in a nanoporous medium from temperature gradient) and catalytic combustion on platinum surface is proposed. The concept involves having thermal transpiration membrane utilizes the temperature gradient created by mT-SOFC and catalytic combustion to supply reactants at high temperature to mT-SOFC for its operation. With this concept, catalytic combustion modeling and thermal transpiration membrane modeling were studied individually and integrated together for an airbreathing cylindrical chamber. The chamber design involves an aluminum cylinder wrapped with glass microfiber filter as transpiration membrane. Aluminum structure provides practically 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 mT-SOFC. It was found that the temperature, fuel flow rate and equivalence ratio can be varied over mT-SOFC operation range. The integrated system demonstrates capability in self-sustaining power generation using hydrocarbon fuel without moving parts. (paper)