Multi-Step Consecutive Photo-Chlorination of 1,2-Dichloroethane: Kinetics and Reactive Distillation Experiment

The development and validation of a novel kinetic model for the chlorination of 1,2-dichloroethane to ultimately hexachloroethane catalyzed by blue light are presented. A factor (X^m) related to the chlorination depth was introduced into the kinetics model, and the results showed that the dynamic features of the photo-chlorination are better predicted by the modified model than by the conventional one. Furthermore, to enhance the selectivity towards tetrachloroethane and pentachloroethane, a novel reactive distillation with side-reactor configuration (SRC) for the photo-chlorination process was proposed. In order to demonstrate the technical feasibility of the process, semi-batch SRC experiments on the laboratory scale were carried out. Up to 96.5 wt % of tetrachloroethane and pentachloroethane with molar ratios varying from 7 to 0.7 over time were obtained in the bottom product.