A compact fuel processor integrated with 75kw PEM Fuel Cells

Due to difficulties and inconveniences in storing and transporting of high-pressure pure hydrogen, hydrogen source becomes one of the technical bottlenecks of the commercialization of fuel cell. In this thesis, a compact autothermal reformer suitable for liquid fuel was developed. The fuel processor consists of a fuel evaporating step, two-stage reformer and a two-stage reactor of water gas shift (WGS, one for high temperature water gas shift and the other for low temperature water gas shifter) and a four-stage preferential oxidation (PROX) reactor and some internal heat exchanger in order to achieve optimized heat integration. It is designed to provide enough hydrogen for 75kWel fuel cells. The fuel reformer was combined with polymer electrolyte membrane fuel cells (PEM FC) and a system test of the process chain was successfully performed. During three hours´ coupling experiment, the fuel processing system and the fuel cells all has been running smoothly. The volume concentration of H₂ and CO in product gas (dry basis) was kept in 53% and 20ppm respectively, completely meeting the requirements of PEM fuel cells. The conversion efficiency of the hydrogen producing system based on LHV of fuel and hydrogen can exceed 95.85%. The fuel cells stacks put up strong resistance to CO and its maximum electronic load to the fuel cells reaches 75.5kW. According to the experimental results, the hydrogen source system can produce hydrogen 70.5 m³/hr and its specific gravity power and specific volume power reach 255W/kg and 450W/L respectively. It indicates that it is feasible technically for supplying hydrogen for Proton Exchange Membrane Fuel Cells by catalytic reforming of hydrogen-rich liquid fuel on-board or on-site.