Abstract: Disclosed is a method for preparing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane, in which method the heat required for the thermal cracking is supplied via a liquid or condensing heat transfer medium, wherein, the heat transfer medium is heated at least in part by means of waste heat from a plant for combusting liquid and/or gaseous residues of a chemical plant. The invention also relates to a plant for preparing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane. The heat required for thermal cracking can be obtained from cheaply available waste heat. For example, it is possible to temporarily heat the heat transfer medium exclusively by means of the second heating device operated by waste heat, wherein said waste heat can, for example, be waste heat from a plant for preparing vinyl chloride.