Thermal and Catalytic Decomposition of Hydroxylammonium Nitrate (HAN)-Based Propellant

Hydroxylammonium nitrate, abbreviated as HAN, is an ionic solution comprising NH3OH+ as the cation and NO3− as the anion. This study involved the preparation of binary HAN-water solutions, ternary HAN-Methanol (MeOH)-water solutions, and HAN-Ethanol (EtOH)-water solutions. The characterization of these solutions as monopropellants was conducted through analytical techniques such as Differential Scanning Calorimetry (DSC) and Raman spectroscopy. Subsequently, the thermal decomposition of both binary and ternary HAN-based monopropellants was investigated using various methods with solid synthesized catalysts. Diverse metals and various support shapes were employed to prepare a range of catalysts. Simultaneously, the reaction mechanism was developed, compared with existing literature, and thoroughly discussed. Lastly, firing tests of the HAN thruster were conducted using a 20N class thruster over monolithic shape catalysts.