Experimental Investigation of Solubility and Vapor Neutralization of JPX Fuel

The JPX rocket fuel is a mixture of unsymmetrical dimethyl hydrazine and a nearly light hydrocarbon fuel. Regarding the presence of unsymmetrical dimethyl hydrazine and olefin compounds in the JPX fuel, emission of its vapors during fuel charging can be hazardous. On the other hand, after fuel charging, the internal surface of pipeline and related equipment is wetted with the liquid fuel. This fuel is hazardous from safety and environmental viewpoint and it is necessary to neutralize the vapors and wash the related equipment with an appropriate solvent. Aqueous solution of ethanol (5%) was selected for the equipment washing. Various oxidants were also compared for vapor neutralization and potassium permanganate was selected. Results showed that the oxidation reaction consists of two steps: in the first step, the potassium permanganate is reduced to manganese dioxide and in the second step, manganese dioxide is reduced to Mn(II) ion. The molar ratio of potassium permanganate to dimethyl hydrazine was found to be 0.506. Assuming the second order reaction with respect to dimethyl hydrazine, the rate constant was determined to be 6.1lit.mol-1min-1 at 25°C. The main products of the oxidation reaction included formaldehyde dimethyl hydrazone, dimethyl amine, ammonia, and water.