Hydroxylammonium nitrate as green propellant: Decomposition and stability

Binary hydroxyl ammonium nitrate (HAN) aqueous mixtures have been prepared. Four series of ternary mixtures have been synthesized with methanol and ethanol as fuels: two series with HAN excess and two other series with stoichiometric fuel contents. Thermal and catalytic decomposition of the prepared solutions have been analyzed. For binary HAN solutions, the thermal decomposition starts only once water has been fully vaporized and the oxidizer is in the liquid state. The influence of the fuel depends strongly on the oxidizer. Methanol and ethanol are vaporized before the decomposition, leading to results close to those observed for binary mixtures. HAN and HAN-fuel-based solutions display the highest catalytic effect with a temperature decrease of about 100°C.