Efficiency is an easy to apply and strong lever on CO₂-reduction and fuel savings at the same time. Today's transportation means, be it passenger vehicles, trucks, airplanes or even ships rely on an ever increasing supply of electricity. On-board electricity is chiefly produced through a generator driven by the main engine in regimes which are determined by the main engine and leave only little room for optimization for the power production. Thus, on-board power is produced at a fairly low efficiency by conventional means.
Fuel cell auxiliary power units bear the potential to boost the efficiency considerably particularly with applications requiring power over extended periods when the main engine is not in use. Fuel cells provide a solution in that they can be designed for high efficiency of up to 40% from tank to electricity in the future. These units will be in a power range of 5-10 kW for vehicles and trucks. Airplanes will require auxiliary power of a couple of hundred kW. For sake of simplicity it is widely required to use the same fuel that is already on board. Hence, middle distillates like diesel and jet fuel are important sources for short-lived hydrogen.
A reformer technology has been developed and tested over extended periods of up to 2000 hours for these fuels. Conversion rates between 99.9% and 99.999% reformate from commercial premium grade diesel with no soot formation have been achieved applying experimental optimization and computer modeling of the reformer. Lab-scale investigations show that desulphurization of commercial grade jet-fuel is likely to be doable on-board at a technical scale, though substantial effort will still be required in this field. Design data and first testing data of a 5 kW brassboard system combining a middle distillate reformer with a PBI-based high temperature polymer fuel cell will be presented. An outlook for the further development will be provided.