Process for thermal cracking of 1,2-dichloroethane to form vinyl chloride

摘要

An improved process for the preparation of vinyl chloride from 1,2-dichloroethane (EDC) wherein 0.10 to 0.15 % by weight of carbon tetrachloride based on EDC, is used as a cracking promoter and the CHCl3 content is limited to less than 200 ppm. Before being fed to the cracking zone, the EDC is brought almost to the boiling point at 15 to 31 bar and then expanded to 10 to 16 bar with flashing EDC vapors and the fraction which has remained liquid is vaporized externally, and the combined EDC gas streams are heated, after being fed into the cracking furnaces, so that the energy required for cracking is already supplied in the first 75 to 85% of the reaction zone, whereby a conversion of 60 to 70% is obtained at residence time from 10 to 25 seconds and the exit temperature from the reaction zone is 485 DEG to 510 DEG C.