Patent GB-539480-A (GB)
Title: An improved manufacture of normally liquid hydrocarbons by alkylation
IPC: C07C2/62
Filed: 1939-11-13
Abstract: 539,480. Acyclic hydrocarbons. STANDARD OIL DEVELOPMENT CO. Nov. 13, 1939, Nos. 29936 and 29937. Convention dates, Dec. 7, 1938, and Dec. 30,1938. [Class 2 (iii)] The reaction of an isoparaffin with a mono-olefine for the production of a safety fuel is conducted in the presence of those constituents of the product which it is desired to suppress, and which boil above and below the boiling point of the desired fraction. Thus the product may be fractionated to give a fraction of predominantly C 5 -C 7  hydrocarbons, another of predominantly C 8 -C 12  hydrocarbons and a third of C 13  and heavier hydrocarbons, the first and third fractions being recycled to the alkylation zone. In an example, a feed stock comprising mainly isobutylene and isobutane is reacted in the presence of a C 5 -C 7  fraction and also a C 9  and heavier fraction obtained from a previous alkylation. For continuous operation the apparatus shown in the Figure is suitable. The mono-olefin-isoparaffin mixture is compressed and fed through line 2 into a reactor 5, containing a dispersion device such as a porous thimble, a jet, perforated disc or a turbo-mixer in which it meets a liquid inorganic acid catalyst introduced through pipe 23. Since mild conditions are preferable, the emulsion is recycled repeatedly through pipes 8, 9, 37, unit 33, which may be a cooler or a heater, and the reactor 5. When reacted sufficiently, a part of the emulsion is led to cooler 12 and acid separator 15, the acid returning to the reactor 5 and the hydrocarbon layer being led to a stabilizer 27 after passing a pressure reducing valve 26. The liquid product leaving the stabilizer through a pipe 34, heated by coil 36 passes to a fractionator 40 provided with the required trap out-trays to give the fractions - desired, the product being removed through pipe or pipes 43. The light products may be recycled or removed from the system through pipe 45 and the products heavier than those desired through pipe 55. When the catalyst is solid such as aluminium chloride, sodium aluminium halide complex or zinc chloride, it may be supported on pumice, bauxite, activated clay or activated carbon, and packed in the reactor 5 or placed on trays therein. The octane number of the product may be raised by the addition of lead tetraethyl, a branched chain ether or by blending with alkylated aromatic compounds such as ethylbenzene, propylbenzene, methylethylbenzene, trimethylbenzenes, sec:butylbenzene, tert:butylbenzene and methylpropylbenzene, or with hydrogenated triisobutylene. The use of the following catalysts and supports is also mentioned: iron, nickel, aluminium and zinc halides, which may be associated with small amounts of hydrogen halide, boron fluoride, oxides of metals of the fifth group of the Periodic classification in association with sulphuric acid, and acid treated clays such as Marsil clay, Montmorillonite and bentonite. Specifications 515,039 and 526,149 are referred to. The Specification as open to inspection under Sect. 9 comprises also re-cycling any unwanted fraction. In an example a low boiling fraction only is recycled. This subject-matter does not appear in the Specification as accepted.