| abstract |
In a process for recovering pyrolysis energy in the prodn. of vinyl chloride, liq. 1,2-dichloroethane (I) is preheated under pressure, vapourised and led in the gaseous state into a cleavage zone. After incomplete thermal cleavage the hot cleavage gases under pressure are cooled in a heat exchanger through which a heat transfer or cooling agent is passed. The heat exchange medium, after extracting heat from the hot gases, is led off for use in another part of the process. The cooled gas stream is treated in a number of successive distn. zones to recover HCl, vinyl chloride, unconverted (I) and high- and low-boiling components. Process allows utilisation of the pyrolysis heat evolved during cleavage of the (I), and which was previously lost. The heat is esp. used to heat the distn. columns in the prod. sepn. stage. |