MEMS-based components of a miniature fuel cell/fuel reformer system

The components of a novel miniature fuel cell/fuel reformer system fueled by liquid gases such as butane and propane were prototyped by MEMS technology and tested. In this system, fuel, air and water are supplied to the fuel reformer by utilizing the vapor pressure of the liquid gas for the reduction of power consumption by peripherals and the simplification of the system. The system is composed of a reforming reactor, a catalytic combustor, a polymer electrolyte fuel cell (PEFC), an ejector to supply air to the combustor and other peripherals. The reforming reactor demonstrated the steam reforming of methanol at an equivalent power of 200 mW and a total efficiency of 6%. The combustor had a stable combustion area above 5 W, and the complete combustion of butane was confirmed by gas chromatography. The ejector showed a potential to supply air required for the complete combustion of butane (31 times larger volume than butane). The PEFC worked, but only at low power density of about 0.1 mW/cm² due to poor adhesion between a polymer electrolyte membrane (PEM) and catalytic electrodes.