Investigating the performance of catalysts in the reaction of heterogeneous decomposition of hydrazine and ammonia using spatial thrusters

In this research, the heterogeneous decomposition reaction of hydrazine and ammonia in a space propulsion system of hydrazine monopropellant type with an adiabatic fixed bed reactor and ۳۰% iridium catalyst (.....)is used to create a thrust force of ۱۰ newtons and aspecific impulse of ۲۳۰ seconds and the application of position change or orbital motion. This process is created by two heterogeneous reactions and turning into hot light gases of hydrogen and nitrogen leaving the reactor bed and then the nozzle of the thrust force in the opposite direction of the gas flow. Considering that the iridium ۳۰%(.....) is a reference and main catalyst that has suitable mechanical, physical, and thermal properties but is very rare and expensive, the purpose of using a nickel replacement catalyst ۱۵% is (...)Compared to iridium, this catalyst is very abundant and cheap, and has functional characteristics, suitable and close to iridium. Regarding the correctness and accuracy of the performance results of two catalysts in a space propulsion system and vacuum conditions and the same static and operational test in a stable and uniform flow of hydrazine to the reactor bed for ۳۰ seconds were measured and evaluated by evaluation indicators such as creating force Thrust (۱۰ newtons), special impulse (about ۲۳۰ seconds), bed pressure drop (less than ۱ bar), minimum amount of ammonia decomposition are compared. Finally, due to the compatibility of nickel catalysts with iridium, a suitable alternative is approved.

کلیدواژه ها:

Heterogeneous decomposition reaction ، Hydrazine ، Steady flow ، Kinetics ، Nickel and Iridium based on gamma alumina catalysts