A theoretical study on decomposition of carbon tetrachloride, trichloroethylene and ethyl chloride in dry air under the influence of an electron beam

New experimental data were published in literature regarding CCl4, C2HCl3 a nd C2H5Cl decomposition in dry air under electron beam influence. Taking in to account experimental data theoretical models of those species decomposit ion were established and computer simulations were performed by the authors of this work to find the kinetics of such processes. The results of the ca lculations and experimental data show that CCl4 decomposition depends on de livered dose and initial CCl4 concentrations. The calculation revealed that recombination of CCl4+ and Cl- is the source of CCl3 radicals and that rea ction may have an important role in the process of CCl4 decomposition. A th eoretical model of C2HCl3 decomposition in dry air under electron beam infl uence describes the decay of C2HCl3 and the formation of several products s uch as Cl-2, CCl2O, CO, CO2, HCl and C2HCl3O. The detailed comparison of ex perimental and theoretical data shows relatively good agreement in efficien cy of C2HCl3 decomposition process, but it can be achieved only with an ass umption that the relation between rate constants of C2HCl4O intermediate pr oduct decomposition (C2HCl3O + Cl and COCl2 + CHCl2) should be around 20 an d C2HCl3O oxidation rate should be not lower than 7.5 x 10(-11) cm(3)/mols. All those rate constants are not yet established experimentally. The resul ts of the calculation of C2H5Cl decomposition and the data obtained experim entally were compared. The temperature, gas pressure, initial C2H5Cl concen tration and dose range were equal in both cases. An elaborated model allow us to obtain quantitatively similar results as the experiments, but the deg ree of C2H5Cl decomposition for certain dose levels is significantly higher in experimental data. It is quite probable that some important processes h ave not been included to the theoretical model. (C) 2000 Elsevier Science L td. All rights reserved.