Development of an Environmentally Acceptable Thermal Treatment Alternative for Energetic Material

Abstract

Alternatives to the open burn/open detonation (OB/OD) disposal of energetic materials are being actively investigated by both the government and industry because of increasing restrictions being imposed by the various air quality districts and governmental agencies. Aerojet has developed a system that can dispose of these types of materials in a three-step process that meets all environmental regulatory requirements. Step 1 is the removal of the energetic material from its container, if required, using high pressure water. Step 2 involves macerating the material in water to facilitate desensitization of Class 1.1 and Class 1.3 energetic materials prior to incineration (Step 3) which is structured around a dual chamber, fixed hearth incinerator designed to operate under negative pressure to eliminate fugitive emissions. This incinerator is a two-stage, controlled-air unit equipped with tandem liquid scrubbers capable of limiting particulates to less than 1.0 micron with a 95% efficiency at 0.5 micron, a design requirement imposed by its originally intended use in the nuclear industry where high efficiency particulate adsorber (HEPA) filters were required on the output to ensure the capture of radioactive particles. Adapting the basic design to handling energetic materials principally involved the selection of different refractory materials; the original design produced a clean burning, low emissions incinerator capable of handling a variety of combustible solid and liquid feed streams. Additional improvements in emissions levels were made possible by using orthogonal experimental arrays and analyses based on Taguchi Methods®. This approach provided the needed insight into the effects of controllable factors on emissions to permit optimization of the operating parameters for the incinerator. Combustion efficiencies of 99.98+%, destruction and removal efficiencies (DRE) of 99.99+%, and emissions levels well below regulatory limits have been consistently observed which demonstrates the efficacy of this incinerator design and of the experimental approach used for operational optimization.