Abstract: A process for the purification of 1,2-dichloroethane is described, in which the crude product, containing not more than 3% by weight of high-boilers, is distilled in a first column at 125.degree. to 180.degree. C. in such a way that the bottom product contains not more than 7% by weight of high-boilers. The purified, vaporous 1,2-dichloroethane discharged at the head of this column is used to heat product streams containing 1,2-dichloroethane. The bottom product from the first column is distilled in a second column, advantageously at a pressure of 5 to 40 kPa, together with a feed composed of vaporous 1,2-dichloroethane obtained from the reaction of ethylene with chlorine. The process makes it possible to purify 1,2-dichloroethane with a saving in energy.

Abstract: Vinyl chloride is produced by pyrolytic decomposition of 1,2-dichloroethane in a furnace with coiled up reaction tube having an internal diameter of from 12 to 16 cm. The dichloroethane is vaporized completely in the convection zone of the pyrolytic furnace, different amounts of heat are supplied to the different zones of the reaction tube and, after decomposition in the working up of the reaction products, the low-boiling constitutents are treated with chlorine and separated together with the high-boiling constituents.