(514b) Enhancements on Diesel Autothermal Reformer for Low-Temperature Solid Oxide Fuel Cell Integration

A Diesel autothermal reformer has been improved to integrate with low-temperature Solid Oxide Fuel Cell (SOFC) stack for Auxiliary Power Unit (APU) applications. The Diesel reformer can provide hydrogen-rich reformate to the SOFC stack with a hydrocarbon reforming reaction. For the low-temperature SOFC stack, considerations on sulfur removal and heat management have to be done with the design process of the Diesel reformer. Liquid hydrocarbon fuels such as Diesel commonly have a small amount of sulfur content, and it has to be removed for stable operation of the fuel cell stack. In particular, for the low-temperature SOFC stack, the sulfur contents have to be reduced to less than ppm level. The desulfurizer can be located after the Diesel reformer to reduce the sulfur level, but its operating temperature is around 350-400°C, which is less than the operating temperature of the SOFC stack. Therefore, the reformate has to be re-heated to be supplied to the SOFC anode to ensure the stable operation. Heat exchangers can be designed to utilize waste heat from the SOFC stack and provide the heat to the reformate. For the low-temperature SOFC stack, the burden of the heat exchangers can be decreased, and overall system size can be reduced. With those considerations, enhancements on Diesel autothermal reformer for the low-temperature SOFC have been studied in order to improve overall system efficiency. A prototype of the 1 kW_e Diesel reformer system has been developed and tested to validate the improvements for the low-temperature SOFC application. In result, 950 W of electricity could be produced with the system.