ADVANCED MODELING OF INCINERATION OF BUILDING DECONTAMINATION RESIDUE
Citation:
Bockelie, M., M. Denison, C. Montgomery, W. Zhao, A. Sarofim, AND P. M. LEMIEUX. ADVANCED MODELING OF INCINERATION OF BUILDING DECONTAMINATION RESIDUE. Presented at Air & Waste Management Association's 98th Ann. Conf.l, Minneapolis, MN, June 21 - 24, 2005.
Impact/Purpose:
The EPA National Homeland Security Research Center (NHSRC) has initiated research to develop better methods, technologies, and guidance relating to building decontamination in the event of a terror attack. Incineration is one of the primary technologies being studied for the disposal of contaminated building materials. As part of that effort, Reaction Engineering International (REI), under contract to EPA, is developing advanced computer simulation tools for analyzing incinerators processing building material contaminated by biological weapon (BW) chemical/biological (CB) agents. The model results are being compared against pilot-scale data collected by EPA to characterize the behavior of BW agents, as would be found in a structure, bound in various matrices and materials, typical of an office building/environment. The models will be used to extrapolate heat transfer, fluid dynamics, and chemical kinetic behavior to characterize the full-scale effect.
The models being developed will take advantage of a Department of Defense (DoD) Small Business Innovative Research (SBIR) program recently completed by REI to develop a suite of models for conducting detailed simulations of chemical demilitarization incinerator operation. As part of that SBIR project, computational chemistry methods were used to develop detailed chemical kinetic mechanisms to describe the decomposition of CW agents of mustard, GB and VX.
The simulation tools provide the ability to analyze the performance and emissions from incinerator units under a broad range of operating conditions and configurations for different munitions and storage containers. The models used within the incinerator simulations provide detailed information on the local gas properties, such as gas temperature, species concentrations (e.g., oxygen, agent, combustion products, products of incomplete combustion), pressure, etc. The models also provide detailed information on the surface temperatures and heat fluxes to the furnace walls, munitions and equipment within the incinerator. The models will provide the ability to study a wide range of "what if" scenarios for baseline operation and furnace upsets. Overall, the models provide a tool to help establish safe and efficient procedures for the incineration systems to reduce the cost and schedule of processing contaminated building materials.
To simulate the performance of an incineration plant, a combination of deetailed Computational Fluid Dynamic (CFD) models and fast running process (mass/energy balance) models are used.
The CFD models include the detailed chemistry and physics req;uired to analyze the incinerator units and corresponding afterburners. These models contain 3D furnace and canister geometrics and all of the relevant physics and chemistry. The models include the full coupling of turbulent fluid mechanics, all modes of heat transfer (including radiation) and equilibrium combustion chemistry for agent and fuel. Destruction of chemical agent is predicted using non-equilibrium (finite rate) chemistry models that include full and reduced chemical kinetic mechanisms.
The chemistry sub-models used to describe the destruction of GB, VX and mustard are based on work originally performed under a US Army funded Multiple University Research Initiative (MURI) grant (ARO Grant DAAL03-92-G-0113), led by Prof. Freed Goulding, that laid the groundwork for developing a basic understanding of the incineration chemistry involved in destroying Chemical Warfare Agent (CWA). There is relatively little reliable, quantitative, experimental data for agent destruction. Our models that describe agent destruction have been developed by generating chemical kinetic rate constants and thermochemical data for species and reactions not available in the literature. The chemical kinetic rates are estimated from heats of reaction, structural considerations, and estimates of barrier heights. Thermochemical information is obtained f
Description:
abstract presentation