Patent GB-603809-A (GB)
Title: Production of unsaturated halogenated hydrocarbons
IPC: B01J27/06
Filed: 1945-10-30
Abstract: A catalyst used in the addition of halogens to ethylene comprises dehydrated calcium chloride, which may be used as such or with a halide of barium, strontium, beryllium, nickel, iron, cobalt, copper, lead, molybdenum, antimony, or aluminium.  The catalyst may be in the form of granules, pellets, or powder, mixed with or deposited on carriers such as pumice, silica, silica gel, asbestos or charcoal.ALSO:<PICT:0603809/IV(b)/1> Unsaturated halogenated hydrocarbons are obtained from hydrocarbons containing olefines by introducing a portion of said hydrocarbons into a first halogenation zone, introducing the remaining hydrocarbons into a second (separate) halogenation zone, halogenating the hydrocarbons in the first zone to give saturated halogenated hydrocarbons, dehydrohalogenating these in a dehydrohalogenation zone to give the unsaturated halogenated hydrocarbons and hydrogen halide, passing the hydrogen halide together with oxygen and a catalyst comprising a halide of a metal of variable valency to the second halogenation zone and reacting them with the second batch of olefine-containing hydrocarbons at 150-300 DEG  C., and passing the saturated halogenated hydrocarbons so obtained to the dehydrohalogenation zone.  The invention is described in its application to the production of vinyl chloride from ethylene or gaseous mixtures containing it, such as those obtained in the distillation or thermal or catalytic treatment of petroleum. Referring to the drawing, such a mixture is introduced through line 1, and split into two portions, the first of which goes through line 2 to reactor 3.  Chlorine is introduced to line 2 through valved line 4.  The catalyst in reactor 3 may be calcium chloride, which may be used with a halide of barium, strontium, beryllium, nickel, iron, cobalt, copper, lead, molybdenum, aluminium, antimony and may be in the form of granules, pellets or powder or on a carrier such as pumice, silica, silica gel, asbestos or charcoal. Temperature is maintained at 20-150 DEG  C. in reactor 3 by means of a heater 5 positioned in line 1.  As the reaction is exothermic, a valved line 6 is provided to byepass the heater.  Effluence from reactor 3 is passed to an ethylene dichloride concentrating zone comprising cooler 9, flashing chambers 11 and 14 which separate gaseous constituents, stripping column 20 and fractionator 24. The separated ethylene dichloride is fed to accumulator 28 and through heater 30 to a dehydrohalogenation zone consisting of externally heated tubes 32 in furnace structure 33, the tubes being packed with contact material such as pumice, silica stone, or crushed brick, and the temperature being 400-880 DEG  C. Effluence from 32 is passed through cooler 35 to stripping column 36 from the top of which hydrogen chloride is withdrawn.  Liquid comprising vinyl chloride is withdrawn from the bottom of 36 and fed to fractionator 38, where the vinyl chloride is drawn off as a vapour, and ethylene dichloride drawn off from the bottom is recycled to stripping column 20.  The second portion of olefine-containing mixture is passed from line 1 to reactor 48, which is also supplied with oxygen through line 50 and heating coil 51, hydrogen chloride from column 36 through line 54, and, to assist in temperature control, steam through lines 57 and 58, and water through line 59 and manifold 60.  Catalysts for use in reactor 48 comprise the chlorides of copper, iron, strontium, titanium, vanadium, chromium, manganese, cobalt and nickel, in conjunction with the usual carriers.  Catalyst is transported from storage vessel 62 to reactor 48 by means of air introduced by line 64 into line 63.  Catalyst entrained with reaction products from 48 is separated by cyclone separator 67.  The effluence from 67 is passed to washtower 71 and scrubber 74 to tower 76, to the top of which kerosene is supplied to extract the ethylene dichloride. The mixture of ethylene dichloride and kerosene is separated in still 79, and the ethylene dichloride taken overhead is passed via cooler 81, accumulator 82 and line 86 to column 20.  Vinyl bromide may be produced similarly and other unsaturated hydrocarbons specified are propylene, butene-1, butene-2, pentene-1, pentene-2, 3-methyl-butene-1, 1-methyl-butene-2, hexene-1, hexene-2, 4-methyl-pentene-1, 3,3-dimethyl-butene-1, 4-methyl-pentene-2, octene-1, cyclopentene, cyclohexene, 3-methyl-cyclohexene.