Alkaline Pressure Hydrolysis of Energetic Materials

Due to the reduction of armament and especially to the German reunification we are met by the objective of the disposal of energetic materials. In the next few years there will be approximately 40,000 t of energetic materials to dispose off. Environmentally friendly disposal methods available for different propellants, explosives, and pyrotechnics are urgently needed. The energetic polymer nitrocellulose is the main component of gun and rocket propellants. One method to dispose off nitrocellulose-containing propellants is the combination of a rapid chemical destruction by pressure hydrolysis and the biological degradation of the reaction mixture. The study describes the results of pressure hydrolysis of different gun and rocket propellants. Under alkaline conditions (propellant to NaOH ratio 2.3:1; reaction temperature 150 degree Celsius; pressure below 30 bar) biological degradable reaction products were formed. The main products in the liquid phase were simple mono and dicarboxylic a cids. Dependent on the reaction conditions 30-50 % of the nitrogen content of the propellants was transformed to nitrite and nitrate. The gaseous nitrogen containing products were N2 (16-46%), N2O (2-23%), NOx. (0-5%). Overall 40-60% of the propellant nitrogen was transformed to gaseous products. In the solid residues a nitrogen content between 2 and 9% was found. The residues were mostly due to additives used in propellant manufacturing. In the case of nitrocellulose, the pressure hydrolysis below 30 bar and reaction temperature of about 1500C is sufficient.