Patent GB-759173-A (GB)
Title: Improvements in or relating to the preparation of carbon monofluoride
Inventor: JACOBS CHARLES STANLEY
IPC: C01B31/00
Filed: 1953-10-23
Abstract: Small amounts of fluoro- and fluoro-chlorocarbons and carbon monofluoride are prepared by submitting carbon to the joint action of fluorine and chlorine, the molar ratio of fluorine to chlorine being in the range 0.2-2 1/2 mols. of fluorine per mol. of chlorine, at a temperature of at least 400 DEG  C. but less than 500 DEG  C.  The molar ratio F:Cl may be 0.75:1 to 1.25:1, but preferably an equimolar ratio is employed, and the fluorine and chlorine may be a mixture, an interhalogen compound, e.g. chlorine monofluoride, or a mixture of the latter with one of the elements.  The halogens may be preheated to 400-500 DEG  C. in a nickel preheater and are contacted with graphite in a shallow nickel boat in a nickel reactor at 425-475 DEG C.  The effluent gases may be passed through traps held at different temperatures to recover chlorine, which is recycled, and the small amounts of fluoro- and fluoro-chlorocarbons.  Solid products having formul  CF0,92 and CF1,03 are referred to.  Alternatively, the halogens may be passed through a bed of graphite which may be fluidized.  The solid carbon monofluoride may be decomposed by heating at low pressure, e.g. 500-600 DEG  C. at 0.5 cm. Hg, yields a mixture of fluorocarbons of average molecular composition C2,5 F6,8 (CF4, C2F4, C2F6, C3F8, C4F10, C5F12, C6F14, C5F10, and C6F12) and a mixture of fluoroaromatic compounds having condensed nuclei.  Heating in nitrogen at 500-600 DEG  C. yields a mixture of fluorocarbons of average molecular composition C2,5F7,9, the above mixture of fluoro-aromatic compounds having condensed nuclei, and a fluoro-carbon oil believed to be a mixture of fluoroaromatic compounds having condensed nuclei with aliphatic side chains. Heating at 400-600 DEG  C. in chlorine yields fully halogenated fluoro-, or fluorochloro-derivatives of methane, ethane, propane, butane, pentane, and hexane, containing not more than 2 chlorine atoms per molecule, a compound of empirical formula C17,8F18Cl, and the mixture of fluoroaromatic compounds having condensed nuclei.ALSO:Carbon monofluoride is prepared by submitting carbon to the joint action of fluorine and chlorine, the molar ratio of fluorine to chlorine being in the range 0.2-2 1/2 moles of fluorine per mole of chlorine, at a temperature of at least 400 DEG C. but less than 500 DEG C.  The molar ratio F:Cl may be 0.75:1 to 1.25:1, but preferably an equimolar ratio is employed, and the fluorine and chlorine may be a mixture, an interhalogen compound, e.g. chlorine monofluoride or a mixture of the latter with one of the elements. The halogens may be preheated to 400 DEG -500 DEG C. in a nickel preheater, and are contacted with graphite in a shallow nickel boat in a nickel reactor at 425 DEG -475 DEG C.  The effluent gases may be passed through traps held at different temperatures to recover chlorine, which is recycled, and small amounts of fluoro- and fluorochlorocarbons.  Solids products having formul  CF0.92 and CF1.03\t are referred to. Alternatively, the halogens may be passed through a bed of graphite which may be fluidized.  The solid carbon monofluoride may be decomposed by heating at low pressure, e.g. 500 DEG -600 DEG C. at 0.5 cm. Hg, yields a mixture of fluorocarbons of average molecular composition C2.5, F6.8, (CF4, C2F4, C2F6, C3F8, C4F10, C5F12, C6F14, C5F10 and C6F12) and a mixture of fluoroaromatic compounds having condensed nuclei.  Heating in nitrogen at 500 DEG -600 DEG C. yields a mixture of fluorocarbons of average molecular composition C2.5F7.9, the above mixture of fluoroaromatic compounds having condensed nuclei, and a fluorocarbon oil believed to be a mixture of fluoroaromatic compounds having condensed nuclei with aliphatic side chains.  Heating at 400 DEG 600 DEG C. in chlorine yields fully halogenated fluoro-, or fluorochloro-derivatives of methane, ethane, propane, butane, pentane, and hexane, containing not more than 2 chlorine atoms per molecule, a compound of empirical formula C17.8F18Cl, and the mixture of fluoroaromatic compounds having condensed nuclei.