Patent GB-1119448-A (GB)
Title: Chemical equipment and process
IPC: C07C2/78
Filed: 1965-07-14
Abstract: Acetylene is produced by means of a flame reaction from a saturated or olefinically unsaturated hydrocarbon and chlorine by passage through a burner orifice adjacent to which is provided a heat source. Other products of reaction may include ethylene.  As described the hydrocarbon is methane, e.g. as natural gas.  It is stated that the heat source may comprise an electric heating wire or a small portion of radio-active material, which may be enclosed in ceramic material. As described, however, the heat source is a burner for an auxiliary flame reaction in which a hydrocarbon burns with oxygen, to which the principal reactants are also fed. The heat source may be maintained at ignition temperature and the gaseous reactant stream may comprise catalytic, modifying and/or diluent materials.  The flame is preferably directed into a reaction zone in which a curtain of liquid flows down the walls to prevent corrosion and deposition thereon. The liquid for the flowing curtain may be water, an aqueous salt solution or a salt melt, e.g. aqueous Na2SO4 or HgCl2 or a melt of KCl, ZnCl2 an HgCl2.  The residence time of the gas in the reaction zone is preferably within the range 0.01 and 0.001 second.  Said zone preferably narrows to form a quenching zone in which the liquid becomes entrained in the reactants. Alternatively a cooling liquid may be injected into a quenching zone.  Once the reaction has been started, oxygen may be supplied with the reactants to stabilize the flame.  Where an auxiliary flame heat source is used, the oxygen supply to the auxiliary burner may be replaced by oxygen supplied through the chlorine inlet.ALSO:Vinyl chloride is produced by means of a flame reaction from a saturated or olefinically unsaturated hydrocarbon and chlorine by passage through a burner orifice adjacent to which is provided a heat source.  Other products of reaction include methyl chloride. As described the hydrocarbon is methane, e.g. as natural gas.  It is stated that the heat source may comprise an electric heating wire or a small portion of radioactive material, which may be enclosed in ceramic material.  As described, however, the heat source is a burner for an auxiliary flame reaction in which a hydrocarbon burns with oxygen, to which the principal reactants are also fed.  The heat source may be maintained at ignition temperature and the gaseous reactant stream may comprise catalytic, modifying and/or diluent materials. The flame is preferably directed into a reaction zone in which a curtain of liquid flows down the walls to prevent corrosion and deposition thereon.  The liquid for the flowing curtain may be water, an aqueous salt solution or a salt melt, e.g. aqueous Na2SO4 or HgCl2 or a melt of KCl, ZnCl2 and HgCl2, the latter functioning as a catalyst for vinyl chloride formation. The residence time of the gas in the reaction zone is preferably within the range 0.01 and 0.001 second.  Said zone preferably narrows to form a quenching zone in which the liquid becomes entrained in the reactants. Alternatively a cooling liquid may be injected into a quenching zone.  If the residence time of the gas in the above-mentioned narrow zone is 0.1 to 10 seconds at 200 to 500 DEG C, a large proportion of the acetylene initially formed is said to be converted to vinyl chloride.  Once the reaction has been started, oxygen may be supplied with the reactants to stabilize the flame. Where an auxiliary flame heat source is used, the oxygen supply to the auxiliary burner may be replaced by oxygen supplied through the chlorine inlet.ALSO:A flame reactor for producing acetylene and/or vinyl chloride from chlorine and a hydrocarbon comprises a heat source provided at, or substantially at, the burner orifice.  The heat source may comprise an electric heating wire or a small portion of radioactive material, and it is stated that such heating means may be enclosed in corrosion-resistant, insulating material e.g. ceramic material.  As shown in the figures, however, the heat source is a burner for an auxiliary flame reaction into which the principal reactants are also fed.  Thus as shown in Fig. 2, auxiliary hydrocarbon is fed through central tube 10 and oxygen for burning therewith is passed into surrounding coaxial tube through inlet 9, whilst the hydrocarbon and chlorine are passed through tubes 11 and 12 for mixing prior to entry into a further tube surrounding the previously mentioned tubes.  The whole burner, which is removable, is shown at 2 in Fig. 1 and the flame is directed into reactor 3. The reactor is followed in a downstream direction by a quenching zone 7 and this is in turn followed by widened part 8.  The reaction zone is delimited by a curtain of liquid 6 which flows down the walls into which it is directed by means of a guide face 5.  The liquid may be water, an aqueous salt solution or a salt melt and as shown serves, in addition to preventing corrosion of and deposition on the reactor walls, as a quenching liquid by becoming entrained in the reaction products at 7.  Quenching may alternatively be effected by injecting water under pressure into the gases, e.g. as described in Specification No. 850,420.  The liquid curtain may comprise water, a salt solution or a salt melt.