METHOD OF PRODUCING 1,2-DICHLOROETHANE

1. Process for making and purifying 1,2-dichloroethane by reacting ethylene and chlorine in a reaction zone having a liquid medium containing chlorinated C2 -hydrocarbons circulated therein, at a temperature lower than the evaporation temperature of said medium under the pressure prevailing inside the reaction zone, in the presence of a customary chlorination-inducing catalyst and optionally an inhibitor reducing the formation of by-products, with the resultant formation of crude 1,2-dichloroethane, removing the crude dichloroethane from the reaction zone and purifying it in a separate fractionating zone placed downstream thereof, which comprises : a) introducing approximately equimolar proportions of ethylene and chlorine into the circulated liquid medium ; intensively mixing the whole in a mixing zone and then reacting the mixture in a reaction zone at a temperature of about 75-200 degrees C under a pressure of about 1-15 bars, the mean sojourn time of the reaction mixture in the mixing and reaction zone being about 1-15 hours ; b) removing a portion of the liquid reaction mixture from the reaction zone and subdividing said portion into two partial streams, of which one is passed through a heat exchanger to give off calorific energy, and recycled at lower temperature to the mixing and reaction zone ; whilst the second partial stream is introduced into an expansion vessel in which a quantity adequate to the reaction product formed in the reaction zone and optionally also a proportion of 1,2-dichloroethane originating from a third source and introduced into the reaction zone is evaporated from said second partial stream ; resulting vaporous matter is introduced into a fractionating column whilst unevaporated liquid matter of the second partial stream is recycled into the mixing and reaction zone of the circulated liquid medium ; and c) separating distillatively 1,2-dichloroethane from the vaporous matter introduced into the fractionating column with the use of a portion of the heat energy transferred inside the heat exchanger and removing the 1,2-dichloroethane overhead, higher chlorinated products being obtained in the column base portion from which they are removed and worked up separately.