Coupling Experiment of Compact Integrated Fuel Processors with 75kW PEM Fuel Cells

Abstract

A compact autothermal reformer suitable for liquid fuel for instance methanol et al. was developed. The fuel reformer was combined with polymer electrolyte membrane fuel cells (PEM FC) and a system test of the process chain was successfully performed. 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. The fuel processor is designed to provide enough hydrogen for 75kWel fuel cells. After the initial step of methanol ATR, CO WGS and CO PROX steps are used for 'clean-up' CO. The exhaust gas from FC anode feedback to the fuel processor to vaporizes the feedstock of methanol and water by a catalytic combusting-evaporator. 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. 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. 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.