Preparation of TCE and PCE by oxychlorination of EDC and HCl with two-stage series reaction

For the efficient and eco-friendly preparation of trichloroethylene (TCE) and perchloroethylene (PCE), as well as the application of byproduct HCl, a process composed of a two-stage series reaction was firstly proposed using HCl as the chlorine source. Oxidation of HCl to Cl₂ was carried out in the first stage of the process, and the second stage of the process was the oxychlorination of EDC with generated Cl₂ and unreacted O₂ in the first stage to TCE and PCE. These reactions were carried out in series so that the deep oxidation reactions were effectively avoided. In addition, by using the two-stage process, different catalysts and process parameters could be applied in each stage to meet the different reaction needs. The complex Ce-Cu-K/Y catalyst was used in the first stage, and it was applied in the second stage with optimized loading of the active component. The appropriate loadings of K/Cu (mass ratio) and the active component were 0.73 and 45.5%, respectively. Meanwhile, the operation conditions in the second stage of the process were optimized. 83.4% yield of both TCE and PCE, 96.1% yield of organochloride could be obtained at 430℃ with 0.5 h^-1 weight hourly space velocity (WHSV) of EDC, molar ratio of O₂ to EDC 1.8, and molar ratio of O₂ to EDC 2.4. The results presented an encouraging prospect in industrial application.