Limited methodologies exist to measure and predict emissions from use of propellants, pyrotechnics, and explosives. Warfighter exposure and range contamination to potentially harmful pollutants are not fully characterized -- resulting in possible health, clean up, and liability issues. The source of the toxicity and contamination (e.g., metals in some propellants and explosives) remains uncertain, limiting efforts at targeting replacements. The overall technical objective of the program will be the development of pollutant sampling methods for comparison with models. These models define and predict solid and gas-phase physics and chemistry of metal-containing propellants, pyrotechnics, and explosives, enabling predictions of emission factors (EF) and potential for range contamination. The elucidation of the chemical mechanisms of toxic emissions formations will be used as a guide towards mitigation.
The previous work under WP-2611 has successfully demonstrated emission sampling methods for gun firings and explosions and has shown that analysis of stages of energy release can be used to predict emissions in controlled environments. For this project, the technical approach will be the development and validation of models which employ solid, liquid, and gas-phase physics and chemistry (including gas-particle reactions) of metal-containing propellants, pyrotechnics, and explosives, thereby enabling predictions of emission factors. These predicted EFs will be experimentally determined in laboratory and field settings using methods improved upon from the SEED effort and previously funded SERDP projects that successfully developed methods for sampling of propellant burns and detonations. Emission factors allow translation of measured concentrations of emissions for a given process to other scenarios and scales, facilitating prediction of pollutant levels for a given source’s magnitude and frequency. Emission factors are used in conjunction with dispersion and exposure models to establish both human exposure risk and environmental impact, forming the basis of operational procedures, engineering controls, and installation operating permits.
Successful execution of this program will benefit the U.S. Department of Defense (DoD) by allowing safer operation of range facilities, by minimization of pollutant emissions during energetic material testing, and by enhancing soldier safety by improving safeguards against exposure to toxins during the performance of duties. The project will develop a reduced chemical mechanism for the heterogeneous combustion of products of explosions and deflagrations and should contribute to an improved understanding of all energy release processes. This effort should be of significant interest to the scientific community for developing pollution sampling methods and modeling gas/solid reaction chemistry.