Options
1993
Conference Paper
Titel
Druckhydrolyse von Treibmitteln - Neue Möglichkeiten für die Explosivstoffentsorgung.
Alternative
Pressure hydrolysis of propellants - new method of disposal of explosives
Abstract
The combination of chemical and biological degradation offers an attractive alternative to the common used incineration of energetic materials which have to be disposed of. In the case of nitrocellulose based propellants alkaline pressure hydrolysis is suitable for the initial chemical degradation step. The following biological steps (anoxic denitrification; aerobic degradation) require a reaction mixture which does not interfere with biology. In addition energy and material consumption should be minimized and the emission of air pollutants should be avoided as far as possible. In this study the pressure hydrolysis of a double-base propellant (NDT-3) was studied under different alkaline contents of the reactive mixture. Generally, stronger NaOH-content leads to better conversion ratios of the propellant. Under high alkaline content the solid residue is minimized to equal/smaller than 3 percent. The nitrogen of the propellant is converted into NO2 and NO3. In principle the conversion ra tio of NO3 is with about 25-28 percent N and not influenced by the alkaline content. On the contrary the formation of NO2 is strongly dependent on the alkaline content and ranges from 16 to 51 percent. Evolved gases are strictly inhibited under strong alkaline conditions. The emission of NOx for example is reduced to 0,001 percent of the propellant N. The carbon conversion ratio shows a similar behavior. CO2 in form of gaseous CO2 or HCO3 is produced in an amount of approx. 20 percent whereas the chemical oxygen demand (COD) increases with increasing alkaline content. A special problem for the biological steps is the presence of toxic nitro- and aminoaromatic compounds. The results show that also under high alkaline conditions the content of nitro- and aminoaromatic compounds in the aqueous solution is reduced (smaller than 10 mg/l). Alkaline pressure hydrolysis of propellants can be improved by modifying the reaction conditions. In this paper it is demonstrated that strong alkaline c o