Pyrolysis of 1,1,1‐Trichloroethane in the absence and the presence of added HCl and/or CCl₄

Abstract

The title reaction has been studied in a static quartz reaction vessel between 587 and 658 K at pressures between 40 and 152 torr. The dehydrochlorination is the only significant reaction and is autoaccelerated by the produced HC1. Numerical modelling indicates that the Rice-Herzfeld mechanism, generally used for describing the pyrolysis of halogenated ethanes, has to be completed in the case of CC13CH3 with additional transfer reactions converting "dead' radicals into chain carriers and vice-versa. The numerical simulation fits the experimental results, in the absence as well as in the presence of different amounts of added HCI. The dehydrochlorination is also accelerated by the addition of CCl,,, which can be explained in terms of additional elementary steps involving . CC13 radicals.

Pyrolysis of 1-chloro-1,1-difluoroethane: Considerations about its molecular nature

“…It is generally accepted, c however that these reactions occur with zero activation energy and a pre-exponential factor of 10 10.3 L/mol.s [6]. Recombination reactions between two halogenated alkyl radicals are expected to proceed slower.…”

The pyrolysis of CCl4 and C2Cl6 in the gas phase. Mechanistic modeling by thermodynamic and kinetic parameter estimation

“…Only the zero-activation energies, and the thermodynamics of C12 and C1 were fixed at initial conditions. The optimization procedure involves the "principle of detailed balancing" and is the same as in [23]. OPTKIN, a user friendly PC program for mechanistic modeling of reactions by kinetic and thermodynamic parameter optimization (241, has also been used.…”

“…Notice that, as for the pyrolysis of 1,1,1-trichloroethane [23], the fitting of the model to the experimental data is rather insensitive to the choice of the initial values of the parameters. This results from the many degrees of freedom available for the optimization and prevents the choice between possible thermochemical and kinetic data.…”

Kinetics and mechanism of the thermal chlorination of chloroform in the gas phase

“…The simulated and optimized Cl 2 -pressuretime curves were obtained using OPTKIN, a userfriendly PC program for mechanistic modeling of reactions by kinetic and thermodynamic parameter optimization [11]. Applications of this program and examples of the modeling strategy are to be found in [8,10,12,13]. The sensitivity analyses were also performed with OPTKIN.…”