GB740536A - A process for the manufacture of vinyl chloride - Google Patents

Abstract

<PICT:0740536/IV(a)/1> Vinyl chloride is manufactured by the thermal decomposition of dichlorethane, wherein the thermal decomposition is carried out under superatmospheric pressure of at least 5 atmospheres (gauge). The reaction mixture may be worked up by distillation under reduced pressure or the gases may be subjected to distillation at low temperatures after releasing the pressure or hydrogen chloride may be removed by an absorbent, e.g. water or aqueous hydrogen chloride, and the vinyl chloride may be separated from the unreacted dichlorethane by distillation. Using the apparatus shown in the drawing a mixture of 1 : 2- and 1 : 1-dichlorethanes is passed from container 1 to pump 2 and thence to evaporator 3 and heated reactor 4. The mixture of gases formed is cooled in cooler 5 and passed to column 6 where hydrogen chloride is driven off through tube 7. A dephlegmator 8 is supplied with cooling brine. The mixture of vinyl chloride and unreacted dichlorethane collecting in sump 9 is passed to column 10 where vinyl chloride is distilled off and passes through a dephlegmator 11 and further cooler 12 into receiver 13. In the sump 14 unreacted dichlorethane collects and may be recycled. In examples: 1 : 2-dichlorethane is employed as starting material, the reaction tubes are of chrome-molybdenum or refined steels and the mixture of reaction products is separated by distillation at elevated temperature and pressure (1) and (2); or at low temperature and atmosphere pressure (3). It is stated that 1 : 1-dichlorethane may be split in the same manner as the 1 : 2 isomer in example 1. The dichlormethane produced may be recycled. Specification 363,009 is referred to.