Patent GB-535054-A (GB)
Title: A process for the production of saturated hydrocarbons with branched or more highly branched chains from saturated hydrocarbons with branched or less branched chains
IPC: C07C5/27
Filed: 1939-07-14
Abstract: 535,054. Hydrocarbons. NAAMLOOZE VENNOOTSCHAP DE BATAAFSCHE PETROLEUM MAATSCHAPPIJ. July 14, 1939, Nos. 20560, 20561, 20562 and 20563. Convention dates, Aug. 9, 1938, Sept. 16, 1938, Nov. 10, 1938, and Dec. 7, 1938. [Class 2 (iii)] Saturated aliphatic hydrocarbons boiling below 200‹ C. are converted into their morebranched isomers by heating to a temperature not exceeding 200‹ C. in the presence of an aluminium halide as catalyst and of hydrogen under pressure, the latter serving to repress the formation of by-products. Both the hydrogen and the aluminium halide may be formed wholly or in part under the reaction conditions. The initial hydrocarbons are preferably those containing 4-6 carbon atoms in the molecule, but octane may similarly be converted into branched-chain octanes and mixtures of normal hydrocarbons such as natural gas fractions, hydrogenated cracking gas fractions or straight run gasolines into mixtures containing branched or more highly branched hydrocarbons. The process may be effected in the gaseous or liquid phase, and an activating agent for the catalyst, comprising a hydrogen halide or alkyl halide, may be present. The aluminium halides may be employed in the form of durable or complex compounds, e.g. with tripropylbenzene. When the hydrogen is formed in situ it may be generated from metals and a hydrogen halide, e.g. magnesium, aluminium, copper, zinc or silver in the presence of dry hydrochloric acid gas ; whilst the aluminium halide may be formed from aluminium and either hydrogen halide or a halogen compound such as tert-butyl chloride, thionyl chloride or double compounds of the type PbSO 4 .2HCl and CuSO 4 .2HCl. The metals employed in this connection may be mixed or alloyed with other metals or may be activated by treatment with solutions of salts of metals having a higher normal potential; thus, aluminium may be activated by the addition of a little mercury or by treatment with a, mercury sublimate solution. Inert gases such as nitrogen and carbon dioxide may be present during the isomerization process. The hydrocarbon products are useful as motor fuels or for addition to motor fuels to improve their anti-knock properties. Examples are given of the isomerization in an iron or V2A steel autoclave of (1) n-pentane in the presence of aluminium chloride, and of hydrogen and gaseous hydrogen chloride under pressure ; (2) n-pentane using pulverulent aluminium and dry hydrochloric acid under pressure, with aluminium chloride as an optional addition ; (3) n-hexane using aluminium chloride in the presence of hydrogen and hydrogen chloride under pressure ; (4) n-butane in the presence of aluminium chloride, pulverulent magnesium and hydrochloric acid gas under pressure ; the magnesium may be replaced by copper or silver. The temperatures used in the examples range from 40‹ to 120‹ C. Specifications 516,659 and 517,758 are referred to. The Specification as open to inspection under Sect. 91 also states that the process may be carried out continuously, that pumice, silica gel, kaolin, terrane earth and activated alumina may be used as carriers for the aluminium halides, and that the presence of iron and its compounds should preferably be avoided either in the catalyst or in the material of which the apparatus is constructed. It also includes examples of the isomerization of (1) a mixture of n-pentane and isopentane in a rotating autoclave in the presence of aluminium bromide and hydrogen under pressure ; (2) a mixture of n-butane and isobutane in a rotating autoclave in the presence of aluminium chloride and hydrogen under pressure ; (3) a mixture of n-butane and isobutane in a rotating V2A steel autoclave containing aluminium and both hydrochloric acid gas and hydrogen under pressure ; (4) n-pentane in a rotating V2A steel autoclave in the presence of n-butyl chloride, aluminium chloride and hydrogen under pressure ; (5) n-hexane in the presence of a complex compound of aluminium chloride and n-butylbenzene and using a V2A steel autoclave into which gaseous hydrogen chloride and hydrogen are forced under pressure ; (6) a mixture of n-butane and isobutane by passing it with hydrogen and hydrogen chloride under pressure over a tabletted mixture of aluminium chloride and kaolin ; (7) n-butane in a rotating autoclave in the presence of aluminium chloride and of varying amounts of aluminium under a partial pressure of hydrogen chloride ; (8) a mixture of n-pentane and isopentane in a rotating autoclave in the presence of aluminium chloride, aluminium and of hydrogen chloride under pressure ; (9) n-hexane in a V2A steel autoclave containing aluminium and hydrogen chloride ; (10) n-hexane in a V2A steel autoclave charged with aluminium chloride, aluminium and hydrogen chloride ; (11) n-hexane in a V2A steel autoclave containing n-butyl chloride, aluminium chloride and hydrogen under pressure ; (12) n-butane by passing a mixture thereof with isobutane, hydrogen and hydrogen chloride under pressure, after first drying it by contact with silica gel or solid potassium hydroxide and purifying by passage over aluminium chloride and then over common salt, up a reaction tower containing a mixture of aluminium chloride and kaolin compressed in the form of pills, the reaction product being cooled and fractionated to remove the hydrogen and hydrogen chloride. The temperatures used in these examples range from room temperature to 150‹ C. This subject-matter does not appear in the Specification as accepted.