Modeling of the ethylene dichloride (EDC) pyrolysis reaction was performed with respect to 108 reversible elementary reactions with 47 molecular and radical species. Kinetic schemes and reaction pathways have been developed based on thermochemical kinetic theories, such as thermal decomposition of molecules and radical-chain reactions, especially the abstraction of H by a Cl radical. In particular, mass, energy, and momentum conservation equations in a gasphase plug reactor were solved simultaneously with the established reaction mechanisms using a numerical scheme for stiff ordinary differential equations. Because of the characteristics of Cl-catalyzed reaction mechanisms, Cl suppliers play key roles in promoting the reaction conversion. This study reports on the calculation and analysis of the effects Of CCl4, as a promotor, on the process conversion to vinyl chloride monomer, concentration of the coking precursor, changes in the heat required, and the pressure drop. The study addresses quantitatively and qualitatively the reaction mechanisms for the pyrolysis of EDC and the predicted results from the calculation. Simulation results are in good agreement with commercial plant data and, as a result, they should be useful for modifying and optimizing the EDC pyrolysis process.