Patent GB-463851-A (GB)
Title: A process for preparing isooctane
IPC: C07C9/21
Filed: 1935-08-01
Abstract: Iso-octane (2.2.4-trimethyl pentane) is produced by absorbing isobutylene in an acid solution, polymerizing the liquor so as to produce di- and tri-isobutylene, separating the polymers from the acid liquor, concentrating the di-isobutylene, and hydrogenating the concentrate.  The isobutylene may be selectively absorbed from a hydrocarbon mixture such as a butane-butene fraction, in sulphuric, hydrochloric, phosphoric, pyrophosphoric, arsenic, or benzene-sulphonic acid or in an acid liquor obtained by absorption of di-isobutylene in such acids, and polymerization is effected by heating, the polymers being then separated and the di-isobutylene concentrated and hydrogenated.  The hydrogenation is effected in any known manner.  Suitable catalysts are metals of Groups 1, 6, and 8 of the Periodic table such as copper, tungsten, platinum black, copper chromite, copper and nickel with zinc or cobalt, nickel on pumice or alumina; or the oxides, sulphides, and phosphates of these metals, especially those of Group 6 such as chrome oxide gel, molybdenum phosphate, and tungsten disulphide. Various temperatures and pressures may be used; thus colloidal palladium acts at room temperature, but nickel requires over 100 DEG  C. and 10 atmospheres pressure.  In an example, isobutylene is absorbed in sulphuric acid of 50--75 per cent strength at 50 DEG  C. from a butane-butene fraction, and polymerization is effected by heating in a closed vessel with stirring or by passing through a coil at 80--110 DEG  C. The hydrogenation of the di-isobutylene may be effected in an autoclave with stirring, or in the vapour phase by passing over active nickel on pumice at 200--300 DEG  C. and 10,5--17,5 atmospheres.  The preferred nickel catalyst is prepared by heating nickel formate suspended in oil at 309 DEG  C. in hydrogen.  Sulphur may be removed from the initial material, or from the polymer.  In the latter case the polymer may be refluxed with hydrogen peroxide or other oxidizing agent, or washed with mercuric nitrate or the sulphur may be absorbed in silica gel or active nickel.  When a sulphide catalyst is used, the removal of sulphur is unnecessary, and hydrogen sulphide may be added.  The Specification as open to inspection under Sect. 91 includes the subject-matter of Specification 465,459.  This does not appear in the Specification as accepted.ALSO:Isooctane is prepared by hydrogenating di-isobutylene Suitable catalysts are metals of Groups 1, 6 and 8 of the Periodic table such as copper, tungsten, platinum black, copper chromite, copper and nickel with zinc or cobalt, nickel on pumice or alumina; or the oxides sulphides, and phosphates of these metals, especially those of Group 6 such as chromic oxide gel, molybdenum phosphate, and tungsten disulphide. Various temperatures and pressures may be used; thus colloidal palladium acts at room temperature, but nickel requires over 100 DEG C. and 10 atmospheres pressure.  In an example, di-isobutylene may be effected in an autoclave with stirring, or in the vapour phase by passing over nickel on pumice at 200--300 DEG  C. and 10,5--17,5 atmospheres. The preferred nickel catalyst is prepared by heating nickel formate suspended in oil at 300 DEG  C. in hydrogen.  The di-isobutylene or the initial material from which it is prepared, may be freed from sulphur, processes for this purpose being described. When a sulphide catalyst is used, this removal of sulphur is unnecessary, and hydrogen sulphide may be added.  The Specification as open to inspection under Sect. 91 includes the subject-matter of Specification 465,459.  This subject-matter does not appear in the Specification as accepted.