Catalyst pack for hydrogen peroxide monopropellant thruster

Abstract

Silver is one of the common materials used to decompose hydrogen peroxide but it is heavy and does not last very long while manganese catalyst seems to be lighter and lasts longer, giving it the potential to replace silver. Unfortunately, this is yet to be tested. The configuration to produce 100 N thrust by using silver catalyst needs to be determined, and the feasibility of using manganese calcinated on alumina needs to be verified. With theoretical calculation and several trial and error experiments by varying the catalyst pack compaction pressure, injector and nozzle diameters, catalyst pack heating temperature and propellant tank feeding pressure for silver catalyst, the configuration to produce 100 N thrust has been obtained. For manganese catalyst, assorted combinations of alumina sizes and types were tested to be the catalyst carrier. The method of calcination was also developed in order to get the highest amount of manganese deposited and it was found that Sasol ?-alumina spheres with a diameter of 2.4 mm produce the highest amount of manganese deposition with an average of 42% after three calcinations using potassium permanganate as the precursor solution. This was followed by experimental work which found that the usage of manganese calcinated on the alumina cannot cope with high pressure in the thruster and tends to break into small pieces and wash out of the thruster. Silver configuration for producing 100 N thrust has been obtained in this research. Also, it was found that it is not feasible to use manganese with the method described in this work.