Patent GB-795493-A (GB)
Title: Process for isomerizing hydrocarbons
IPC: C07C5/22
Filed: 1956-04-25
Abstract: Hydrocarbons are isomerized by treating with a catalyst consisting of anhydrous hydrogen fluoride admixed with a pre-formed complex of boron trifluoride and a metal fluoride, preferably di-fluorides of iron, cobalt or nickel.  Other metals specified are chromium, molybdenum, tungsten, titanium, manganese, vanadium or zirconium. Hydrocarbons which may be treated include naphthenes, paraffins with or without side chains, cyclo-paraffins, olefines or alkyl aromatic hydrocarbons.  The products may be used as constituents of anti-knock motor fuels. In examples, iron powder is heated in an autoclave at 100 DEG  C. with anhydrous hydrogen fluoride, and after cooling to 23 DEG  C., boron tri-fluoride is pressured in.  After 20 hours a white solid of composition FeF2.BF3 is formed.  Similar complexes using cobalt, nickel, chromium and manganese are described.  The isomerization process may be effected in a fluidized or fixed bed of the catalyst supported on an inert carrier, e.g. charcoal or alkaline earth fluorides, and the hydrocarbon feed passed in up-or down-flow, or injected radially into the reactor.  Alternatively the catalyst may be used as a slurry of one or more metal fluoride / boron trifluoride complexes suspended in hydrogen fluoride, and the hydrocarbon feed is bubbled through the slurry. Alternatively, the slurry catalyst may be passed in countercurrent or co-current with the hydrocarbons over a bed of solid packing material.  Additional boron trifluoride may be admitted.  Hydrogen may also be present. The isomerization is carried out preferably at 10 DEG  to 100 DEG  C. and under atmospheric or higher pressures up to 340 atm., and may be used, for example, to convert n-butane, heptane or pentane to the iso-form, methyl cyclo pentane to cyclohexane, butene-1 to butene-2, or propyl benzene to trimethyl benzene.ALSO:Catalysts for isomerizing hydrocarbons consist of anhydrous hydrogen fluoride admixed with a preformed complex of a metal fluoride and boron trifluoride.  The di-fluorides of iron, cobalt or nickel are preferred but fluorides of chromium, molybdenum, tungsten, titanium, manganese, vanadium or zirconium may also be used.  One or more other halogens may also be present. Hydrocarbons treated are naphthenes, paraffins, including branched chain and cyclo-paraffins, olefines and alkyl aromatic hydrocarbons.  The products may be used as constituents of anti-knock fuels.  In examples, iron powder is heated in an autoclave for 30 minutes at 100 DEG  C. with anhydrous hydrogen fluoride, and after cooling to 23 DEG  C. boron trifluoride is pressured in.  After 20 hours a white solid of composition FeF2 : BF3 is formed.  Similar complexes using cobalt, nickel, chromium and manganese are described. In an alternative process the boron trifluoride and anhydrous hydrogen fluoride are contacted simultaneously with the metal powder. The isomerizing reaction may use the catalyst in fluidized or fixed bed with the catalyst supported on an inert carrier, e.g. charcoal, or fluorides of aluminium or of alkaline earth metals, and the hydrocarbons passed in up or down flow or injected radially into the reactor.  The supported catalyst may be formed into pellets or spheres.  Alternatively a liquid catalyst is used consisting of a slurry of one or more metal fluoride/borontrifluoride complexes mixed with hydrogen fluoride, in which case the hydrocarbons are bubbled through a pool of the slurry.  The liquid catalyst may also be passed in counter current or co-current with the hydrocarbons over a bed of solid packing material.  Additional boron trifluoride may be admitted during the reaction.  Hydrogen may also be present.  The reaction is carried out preferably at 10 DEG  to 100 DEG  C. and under atmospheric or higher pressures up to 340 atmospheres.  The solid catalyst may be reactivated by treating with hydrogen, hydrogen fluoride, boron trifluoride or nitrogen.  The process may be used to convert n-butane, heptane, or pentane to the iso-form; methyl cyclopentane to cyclohexane, butene-1 to butene-2, or propyl benzene to trimethyl benzene.