Endothermic reactions of 1-propanamine on a zirconia catalyst

Abstract

Cooling of critical engine components is important for hypersonic aircraft and endothermic reforming reactions on the fuel could play an important role by taking up some of the heat. Here, we propose using alkylamines that dehydrogenate to nitriles and H2 over ZrO2 catalysts as the endothermic fuel. Temperature programmed desorption (TPD) revealed that 1-propanamine on ZrO2 undergoes dehydrogenation at temperatures below 600 K. At 723 K and below, the selectivity to form H2 and propionitrile is greater than 90 %. Heat measurements at 60 bar show heat uptakes as large as 2000 kJ kg−1 of fuel reacted could be achieved at 723 K. Side reactions at higher conversions and temperatures lowered this value but values above 1000 kJ kg−1 were still obtained at nearly 100 % conversion of the amine. The observation of a significant endothermic effect suggests that the unconventional functional groups in the fuels merit further investigation to achieve a more profound chemical heat sink. Possible ways to apply this approach are discussed.