Abstract
Liquid-phase chlorination of ethylene and 1, 2-dichloroethane in a dark system was investigated, by using an agitated vessel with a flat free gas-liquid interface. The results were analysed to obtain the chemical reaction kinetics through a theoretical treatment of simultaneous absorption and reaction for gas-liquid heterogeneous systems.
The chemical reaction kinetics for chlorine addition to ethylene and. for chlorine substitution to 1, 2-dichloroethane showed respectively (1, 1)- and (1, 2)-order dependencies on the concentrations of ethylene and chlorine. In the absence of ethylene, however, chlorine substitution to 1, 2-dichloroethane, where the reaction occurred homogeneously, obeyed (1, 1)-order dependency on the concentrations of chlorine and 1, 2-dichloroethane.
It is explained by the radical chain mechanisms of chlorine substitution reaction that the presence of ethylene enhances the initiation to produce chlorine radical and that the termination step is controlled by the deactivation of 1, 2-dichloroethyl radical. Without ethylene, the production of chlorine radical is so slow that the deactivation of chlorine radical controls the termination step.
