Fuel-cell drive system with hydrogen generation in test

In the future, drive systems for vehicles with polymer electrolyte membrane fuel cells (PEMFC) may be the environmentally more acceptable alternative to conventional drives with internal combustion engines. The energy carrier may not: be gasoline or diesel, as in combustion engines today, but methanol, which is converted on-board into a hydrogen-rich synthesis gas in a reforming reaction with water. After removal of carbon monoxide in a gas-cleaning step, the conditioned synthesis gas is converted into electricity in a fuel cell using air as the oxidant. The electric energy thus generated serves to supply a vehicle's electric drive system.Based on the process design for a test drive system, a test facility was prepared and assembled at Forschungszentrum Julich (FZJ). Final function tests with the PEMFC and the integrated compact methanol reformer (CMR) were carried out to determine the performance and the dynamic behaviour. With regard to the 50-kW(H-2,)-compact methanol reformer, a special design of catalytic burner was constructed. The burner units, with a total power output of 16 kW, were built and tested under different stales of constant and alternating load. If selecting a specific catalyst loading of 40 g Pt/m(2), the burner emissions are below the super ultra low emission vehicle (SULEV) standard. The stationary performance test of the CMR shows a specific hydrogen production of 6.7 m(N)(3)/(kg(cat) h) for a methanol conversion rate of 95% at 280 degrees C. Measurements of the transient behaviour of the CMR. clearly show a response time of about 20 s, reaching 99% of the hydrogen flow demand due to the Limited performance of the test facility control system. Simulations have been carried out in order to develop a control strategy far hydrogen production by the CMR during the New European Driving Cycle (NEDC). Based on the NEDC, an optimized energy management for the total drive system was evaluated and the characteristic data for different peak load storage systems ate described. (C) 2000 Elsevier Science S.A. All rights reserved