Patent GB-1011762-A (GB)
Title: Dehydrogenation process
Inventor: BAJARS LAIMONIS
IPC: C07C5/56
Filed: 1961-10-19
Abstract: Hydrocarbons containing at least one >CH-CH< group are dehydrogenated by reaction in the vapour phase at at least 400 DEG  C. in the presence of at least one-fourth of a mol. of oxygen per mol. of organic compound, and at least two different halogens (as such or as materials liberating halogen), in a total amount to provide at least 0.001 mol. of halogen per mol. of said organic compound, the partial pressure of said organic compound being less than half an atmosphere when the total pressure is less than one atmosphere, and less than half the total pressure when the latter is one atmosphere or more; and in the presence of a catalyst comprising a metal or an inorganic metal compound.  Specified halogen-liberating materials are hydrogen halides, alkyl halides and ammonium halides.  Specified products obtainable by the process of the invention are styrene, a -methylstyrene, benzene, ethylene, propylene, propadiene, isobutene, butene, butadiene, and isoprene.  Hydrocarbons in general are suitable starting materials, e.g. alkanes, cycloalkanes, alkenes, alkyl aromatic compounds and ethyl and isopropylbenzenes and naphthalenes, such as ethyl toluene and ethyl naphthalene. Specifications 977,146, 983,915, 988,619 and 992,115 are referred to. Reference has been directed by the Comptroller to Specifications 728,656 and 895,500.ALSO:Organic compounds containing at least one >CH-CH< group are dehydrogenated by reaction in the vapour phase at at least 400 DEG  C. in the presence of at least one-fourth of a mol of oxygen per mol of said organic compound, and at least two different halogens (as such or as materials liberating halogen), in a total amount to provide at least 0.001 mol of halogen per mol of said organic compound, the partial pressure of said organic compound being less than half an atmosphere when the total pressure is less than one atmosphere, and less than half the total pressure when the latter is one atmosphere or more; and in the presence of a catalyst comprising a metal or an inorganic metal compound.  Specified halogen-liberating materials are the halogens themselves, hydrogen halides, alkyl halides and ammonium halides. Specified products obtainable by the process of the invention are acrolein, vinyl chloride, acrylonitrile, methyl methacrylate, acrylic acid, vinyl pyridine, methyl isopropenyl ketone, chlorobutadiene, and vinyl compounds in general, e.g. vinylidene halides, vinylidene cyanide, vinyl esters, acrylic, alkyl-acrylic and halo-acrylic acids, esters, amides and nitriles, vinyl halides, vinyl ketones and vinyl pyrrolidone. Other compounds which may be dehydrogenated are alkyl chlorobenzenes, isobutyronitrile, propyl chloride, isobutyl chloride, butyl chloride, ethyl fluoride, chlorofluoroethanes, methyl ethyl ketone, diethyl ketone and methyl propionate; and, in general, haloaryl ethylenes and propylenes, C4- 6 alkyl ketones, C2- 6 aliphatic aldehydes, and C2- 6 cyanoalkanes, haloalkanes and haloalkenes. Specifications 977,146, 983,915, 988,619 and 992,115 are referred to.  Reference has been directed by the Comptroller to Specifications 728,656 and 895,500.