Diesel fuel cell generates clean on-board power
High efficiency, low emissions and silent operation are the main drivers behind fuel cell systems that can be used as auxiliary power units (APUs) in mobile applications, e.g. trucks, caravans or yachts. However, proton exchange membranes (PEMs) operate more efficiently with hydrogen rather than with the ubiquitous hydrocarbon fuels such as diesel found at gas stations. Within FCGEN (Fuel cell based power generation), researchers successfully developed an on-board diesel fuelled fuel-cell system providing efficient electric power in trucks. On-board fuel reforming eliminates the need for hydrogen infrastructure as the APU uses the same fuel as the main engine. The APU system, based on the PEM fuel cell technology, consists of the fuel cell, the autothermal reformer, the balance-of-plant components needed for heat, air and water management, as well as the power conditioning module and the electronic control unit (ECU). Catalytic technologies are used for system heating at start-up, fuel reforming and purification, as well as in anode off-gas combustion. Hydrogen extraction from the diesel fuel happens through autothermal reforming, a catalytic reaction in which the diesel fuel is decomposed into hydrogen, steam, carbon dioxide and carbon monoxide. The carbon monoxide is then converted to carbon dioxide and water. The water is recuperated by the system, thus making it self-sustainable. The carbon dioxide is released into the environment, however, the fuel consumption is about 80 % lower than that of internal combustion engine idling and also the produced amount of carbon dioxide is decreased by 80 %. The system was initially designed for use in truck or recreational vehicle and yacht applications. It generates up to 3 kW of electrical power, but can easily be modified for larger power ranges. On aircraft, for example, it can power air conditioners and refrigerator systems. In addition to lowering carbon emissions, the system also produces little noise, which is highly appreciated in mobile applications.
Keywords
Diesel, fuel cell, trucks, hydrogen, FCGEN, fuel reforming, power conditioning, control
