The preferred way of Oxychlorination uses oxygen as an oxidizing agent. The catalyst bed is fluidized with circulating gas, the oxygen concentration is kept outside the flammable range (oxygen-lean operation). The very small off-gas stream of inerts and carbon oxides which are formed in the process is fed to the by-product revocery. The reaction mixture consisting of C2H4, HCl and O2 is catalytically converted in the reactor to EDC in a highly exothermal reaction at a temperature above 200 °C. The heat is dissipated via internal cooling coils and recovered to generate steam.