Patent GB-609321-A (GB)
Title: Improvements in or relating to hydrocarbon conversion
IPC: C07C6/08
Filed: 1945-10-10
Abstract: Saturated hydrocarbons are subjected to the catalytic action of 0.2 to 4 times by weight of intimately admixed concentrated liquid hydrofluoric acid for a time sufficient to form at least one isomer. Reconstruction of the saturated hydrocarbons to isomers and lower and higher molecular weight hydrocarbons, cyclization, and decrease in unsaturated content are effected.  In addition to hydrofluoric acid which should contain less than about 5 per cent of water, promoters such as compounds formed by reaction on the walls of reactors, materials such as active charcoal or bauxite, and inorganic salts, especially alkali or alkaline-earth fluorides may be present. Reaction is effected at about 50-1000 DEG  F. and up to 5000 p.s.i. or more for a time varying from about a minute to 20 hours or more. Reaction may be effected in a tube heater while, for longer reaction times, a further reactor, with mixing means in the case of liquid or mixed phase reaction, is provided. The hydrocarbon may, alternatively, ascend through a column of acid.  The hydrocarbon product is separated from acid and fractionated, after defluorination if necessary, for example as disclosed in U.S.A.  Specification 2,347,945, to recover desired products, other fractions being re-cycled or otherwise utilized. In examples: (1) a natural gasoline fraction of methylhexane boiling range is agitated with 1 third its volume of concentrated hydrofluoric acid for 26 hours at 270 DEG  F. and pressure to liquefy, giving a product containing hydrocarbons from C3 up to above 100 DEG  C. B.P., which is suitable for blending in motor fuel, or an aviation gasoline cut may be separated and the remainder recycled or otherwise worked up; (2) an isooctane fraction + an equal volume of acid at 70 DEG  F. for 1 hour yields C4-C7 and above, the C4 being used in alkylations, C5-C10 for motor fuel, and C11 and above re-cycled or cracked; (3) a motor fuel range by-product yields an aviation gasoline fraction with lower and higher boiling fractions on conversion at 350 DEG  F. for 40 minutes in mixed liquid-vapour phase.  Specification 550,389 is referred to.ALSO:Saturated hydrocarbons are subjected to the catalytic action of 0.2 to 4 times by weight of intimately admixed concentrated liquid hydrofluoric acid for a time sufficient to form at least one isomer. Reconstruction of the saturated hydrocarbons to isomers and lower and higher molecular weight hydrocarbons, cyclization, and decrease in unsaturated content are effected.  In addition to hydrofluoric acid which should contain less than about 5 per cent of water, promoters such as compounds formed by reaction on the walls of reactors, materials such as active charcoal or bauxite and inorganic salts, especially alkali or alkaline-earth fluorides may be present. Reaction is effected at about 50-1000 DEG  F. and up to 5000 p.s.i. or more for a time varying from about a minute to 20 hours or more. For conversion of butane to isobutane, 400-800 DEG  F., and 250-2500 p.s.i. for 1-100 mins. are preferred. Reaction may be effected in a tube heater while, for larger reaction times, a further reactor, with mixing means in the case of liquid or mixed phase reaction, is provided.  The hydrocarbon may, alternatively, ascend through a column of acid.  The hydrocarbon product is separated from acid and fractionated, after defluorination if necessary, for example as disclosed in U.S.A. Specification 2,347,945, to recover desired products, other fractions being recycled or otherwise utilized.  In examples: (1) a natural gasoline fraction of methylhexane boiling range is agitated with one-third its volume of concentrated hydrofluoric acid for 26 hrs. at 270 DEG  F. and pressure to liquefy, giving a product containing hydrocarbons from C3 up to above 100 DEG C. B.P., which is suitable for blending in motor fuel or an aviation gasoline cut may be separated and the remainder recycled or otherwise worked up; (2) an iso-octane fraction and an equal volume of acid at 70 DEG  F. for 1 hr. yields C4-C7 and above, the C4 being used in alkylations, C5-C10 for motor fuel, and C11 and above recycled or cracked; (3) a motor fuel range by-product yields an aviation gasoline fraction with lower and higher boiling fractions on conversion at 350 DEG  F. for 40 mins. in mixed liquid-vapour phase; (4) and (5) butane is converted to give isobutane and lower and higher hydrocarbons by heating with the acid in a bomb; (6) to (9) isopentane, n-pentane or n-butane are similarly converted to isomers and higher and lower boiling hydrocarbons.  Specification 550,389 is referred to.