| 摘要 |
In the chlorination of ethylene in the liquid phase, an excess stoichiometric amount of chlorine is normally used in order to achieve as complete as possible a conversion of the ethylene. Part of the excess chlorine reacts by substitution and thereby reduces the yield of desired 1,2-dichloroethane. The unreacted excess chlorine therefore has laboriously to be removed in subsequent reaction steps. As a result of the method according to the invention to limit the chlorine excess to less than 600 ppm by weight in the reaction cycle, these disadvantages can be obviated. The constant compliance with such a low chlorine excess without fluctuations is rendered possible in industrial operation by the arrangement according to the invention for the continuous recording of the chlorine concentration, even in the presence of catalysts. |
