On-board hydrogen production for auxiliary power in passenger aircraft

This paper presents the potential of a method for on-demand hydrogen generation from the reaction of activated aluminum powder and water for commercial aircraft applications. The hydrogen produced on-board during flight can be used in a fuel cell to generate electric energy. Results of an investigation of the reaction between aluminum and urine show that, in addition to fresh water, the waste water available on-board the aircraft can be used for hydrogen generation. High reaction rates producing about 200–600 ml/min/g Al of hydrogen at a high yield of about 90% was demonstrated. The possibility to use the available waste water leads to high specific electric energy of up to about 850 Wh/kg. In addition, the aluminum–water reaction enables safe use of hydrogen. A comparison to the traditional hydrogen storage methods is also presented.