GB524252A - An improved manufacture of saturated aliphatic hydrocarbons boiling within the gasoline range - Google Patents

Abstract

524,252. Preparation of paraffin hydrocarbons. STANDARD OIL DEVELOPMENT CO. Jan. 26, 1939, No. 2690. Convention date, Nov, 26, 1938. [Class 2 (iii)] Hydrocarbons boiling mainly within the gasoline range are prepared by contacting a mixture of non-cyclic paraffin hydrocarbons, containing a paraffin hydrocarbon having at least one tertiary carbon atom in the molecule and a further paraffinic hydrocarbon in the presence of an alkylation catalyst selected from the following materials. The halides of aluminium, zinc, antimony, tin, iron, nickel, tungsten tantalum, zirconium and molybdenum. Particularly the chlorides and bromides of these metals or mixtures of them. To these compounds there may be added as activators small amounts of an alkyl halide such as ethyl-, propyl-, tertiary butyl-, tertiary or secondary amyl chloride or bromides thereof. Double halide complexes are also used such as a metal halide-aluminium halide and in particular sodium aluminium chloride, lithium aluminium chloride, antimony aluminium chloride or bromide, sodium aluminium bromide, mercury aluminium bromide, and potassium aluminium chloride. Sulphuric acid may also be used, preferably about 96-98 per cent. concentration. The above catalysts may be used alone or on carriers such as activated alumina, silica gel, bauxite, fuller's earth, Bentonite, Kieselguhr, pumice, infusorial earth, Montmorillonite, Marsil clays, Tonsil, super-filtral and activated Floridin. Clays of the bentonite and montmorillonite type activated by the process of U.S.A. Specification 1,642,871. are particularly desirable as they have some catalytic activity of their own and may in some cases be used alone, particularly when alkyl halides are present as promoters. A small-amount of a dehydrogenation catalyst may be added such as chromium oxide and gels impregnated with salts of nickel chromium aluminium and vanadium. The double halide type of catalysts have their activity in some cases, and may be regenerated by treatment with hydrogen halide or with halogens. The reaction mixture of paraffinic hydrocarbons is contacted with a catalyst at temperatures from 0‹-550‹F. under pressure up to 3,000 lbs. per sq. inch, at the rate of about 7 volumes of mixture per vol. of catalyst per hour. The products may be fractionated and in some cases some fractions returned as desired. It is preferred to use as the reaction mixture a mixture of normally gaseous and normally liquid paraffin hydrocarbons in the proportion of two mols. gaseous to one mol. liquid hydrocarbons. It is a feature of the invention to produce fuels of improved octane number from low grade fuels, and also to use waste paraffinic refinery gases to produce motor fuels. A number of suitable reaction mixtures, and suitable hydrocarbons are mentioned. In examples (1) a mixture of isobutane and iso-octane is treated with a sodium aluminium chloride catalyst at 400‹F. under 3,000 lbs. pressure. (2) A mixture of 88 per cent. isobutane and 12 per cent. iso-octane is treated with an aluminium chloride catalyst in the presence of tertiary butyl chloride. (3) A mixture of iso-butane and normal heptane is treated with a catalyst of sodium aluminium chloride deposited on a carrier of material known under the Registered Trade Mark " Celite."