The pyrolysis of a halogenated ester, methyl chloroacetate (MC), under dilute atmosphere and quasiatmospheric pressure was studied at temperatures from 473 to 1048 K using an alumina tubular reactor. MC was chosen as a surrogate to model the thermal decomposition of ethyl bromoacetate, a chemical warfare agent. A maximum MC conversion of 99.8% was observed at a residence time of 2 s, a temperature of 1048 K, and an inlet mole fraction of 0.01. The following products were quantified: CO, CO2, HCl, methane, ethylene, ethane, propene, chloromethane, dichloromethane, vinyl chloride, chloroethane, and dichloroethane. For the first time, a detailed kinetic model of MC pyrolysis was developed and gave a good prediction of the global reactivity and the formation of most of the major products. Flow rate and sensitivity analyses were made to highlight the different pathways of decomposition during the MC pyrolysis. In a first attempt to extrapolate the results obtained with methyl chloroacetate to ethyl bromoacetate, simulations were run with a modified version of the model developed in this study taking into account the differences in bond dissociation energies induced by the change of the chlorine atom by a bromine one.
Supplementary MaterialKinetic mechanism used in this work given under CHEMKIN format.Thermodynamic data of all species of the mechanism.Scheme of the experimental setup used for running pyrolysis experiments, measured temperature profile in the TR in absence of reaction, and the carbon, oxygen, and chlorine balances, SCF energy, zero-point corrected electronic energy, frequencies and geometry of molecules, radicals and transition states, calculated at the CBS-QB3 level of theory, comparison of the kinetic parameters of reaction R30 in Table 1 with literature data, experimental mole fractions of species in a tabular form.