Increased threat of chemical warfare (CW) agents has renewed interest in their high temperature destruction chemistry. Tri-ethyl phosphate (TEP) is an organo phosphorous compound (OPC) used as a simulant for highly toxic nerve agents such as sarin, GB. This study presents an improved chemical kinetic model for TEP combustion developed using experimental (shock tube and laser absorption) and computational studies within temperature of 1213-1673 K, and at pressures near 1.3 atm. Intermediate carbon monoxide concentration time histories during the experiments are measured using laser absorption spectroscopy at 4580.4 nm. New improved model for TEP combustion is built upon the LLNL OPC incineration mechanism for phosphorous chemistry. Thermochemical data of all phosphorous containing species are reevaluated, either utilizing recently published group values for P-containing species or by quantum chemical calculations (CBS-QB3). TEP decomposition takes place via seven concerted elimination reactions. Computational study to investigate the kinetics of these seven reactions is carried out at CBS-QB3 level of theory. In addition, alternative TEP decomposition pathway via H-abstraction, radical decomposition and combination reactions is added. The updated thermochemical data, reactions and their corresponding rate coefficients are used in the improved TEP kinetic model. The model is utilized to predict intermediate CO time histories during TEP combustion with excellent agreement. Current work shows advancements in our knowledge of combustion kinetics of organo phosphorous compounds via combined experimental and computational strategies.

Improved chemical kinetic model for combustion of sarin simulant based on shock tube experiments and computational investigations

2019 Spring National Meeting

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