Wet air oxidation of energetics and chemical agent surrogates

Abstract Wet air oxidation studies have been conducted on a number of energetic materials and wastewaters derived from energetic materials to demonstrate high destruction levels of specific energetic components. Triple-base propellant, OTTO Fuel (used as a torpedo propellant) and hydrazine-based rocket fuel were energetics of interest. Triple-base propellant contain nitrocellulose, nitroglycerin, and nitroguanidine. OTTO Fuel contains substantial amounts of propylene glycol trinitrate. Hydrazine based rocket fuel contains hydrazine and 1,1-dimethylhydrazine (asymmetrical dimethyl hydrazine or UDMH). A bench scale wet air oxidation study on alkaline hydrolyzates of triple-base propellants indicated that essentially complete destruction of the reactive nitrogen components could be achieved at an oxidation temperature of 280°C. Bench scale wet air oxidation studies on OTTO Fuel wastewaters indicated that a 99+ percent destruction of propylene glycol dinitrate can be achieved at an oxidation temperature of 280°C. Processing OTTO Fuel wastewaters in a continuous flow, full scale wet air oxidation unit achieved even higher destruction levels. Bench scale wet air oxidation studies on hydrazine-based rocket fuel wastewaters indicated that a 99.8 percent destruction of hydrazine and a >99.0 percent destruction of 1,1-dimethylhydrazine can be achieved at an oxidation temperature of 280°C. Again, processing of hydrazine-based rocket fuel wastewaters in a continuous flow, full scale wet air oxidation unit achieved similar destruction levels. The application of wet air oxidation for the destruction of chemical agents has been made by the extrapolation of data from the wet air oxidation of compounds with similar chemical structures or of surrogate compounds. Sarin and V-agents are nerve agents which have an organo-phosphorus structure similar to that of certain commonly used pesticides. Pesticides such as glyphosate and malathion, which have a similar organo-phosphorus structure, are essentially completely destroyed (>99 percent destruction) by wet air oxidation in the temperature range of 200 to 280°C. The chemical agent surrogate, dimethyl methyl phosphonate (DMMP) was wet air oxidized at temperatures of 220 to 280°C. Alkaline hydrolyzed DMMP was wet air oxidized at 280°. All of the oxidized effluents showed a >97.5 percent destruction efficiency for the DMMP. The blister agent, mustard (HD) is a chlorinated sulfide, bis(2-chloroethyl) sulfide. Organic sulfides such as mercaptans can be destroyed by wet air oxidation at 260 to 280°C. It is concluded that the wet air oxidation process is a promising alternative to incineration for disposal of energetics and chemical warfare agents.