Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) and the German Aerospace Center (DLR) have successfully integrated and operated an autothermal kerosene reformer with a high-temperature solid oxide fuel cell (SOFC) designed for auxiliary power generation on-board aircraft.
Aircraft currently obtain their in-flight electric power from generators driven by the engines. An auxiliary gas turbine APU delivers power when the aircraft is on the ground at an airport. Using a fuel-cell APU instead for on-ground and in-flight power would reduce noise, fuel consumption and emissions.
|Boeing is investigating the use of a SOFC APU mounted in the tail section. Click to enlarge.|
Boeing, which is also investigating a SOFC APU concept and targeting a 2015 deployment, estimates that a 440 kW SOFC APU could reduce the consumption of Jet-A fuel used for power generation by 40% at cruise, and by 75% on the ground.
ISE and DLR worked in cooperation with Liebherr Aerospace, the coordinator of the EU-funded Power Optimized Aircraft project.
Fraunhofer ISE developed the reformer, including heat exchangers and off-gas burners. The DLR constructed the SOFC stack developed at the Research Centre Jülich (FZJ) and integrated it with the reformer into a test stand.
A porous burner combusts a fraction of the fuel gas from the SOFC that is not converted to hydrogen, thereby supplying the heat required to evaporate and pre-heat the reactant flows to the reformer and the cathode air for the SOFC.
Operating together with the SOFC, the reformer system produced synthesis gas with a flow rate of 10 to 45 Nl/min (normal liters/minute). Desulfurized Jet A-1 kerosene was the fuel. Removing sulfur from the kerosene is an important aspect for the future application of such combined reformer fuel-cell systems, and Fraunhofer ISE successfully tested two desulfurization processes as part of the work.