GB498526A - Improvements in the manufacture and production of valuable liquid hydrocarbons by polymerisation of olefines - Google Patents

Abstract

Gases containing more than 30 and preferably 40 per cent or more of olefines with up to 5 carbon atoms, mainly butylenes or amylenes or both, are polymerized with catalysts of the Friedel Crafts' type, the products being subjected to hydrogenation and a treatment with superheated steam in the presence of caustic alkali. Gases containing butylenes and propylene are especially suitable. They may be obtained by hydrogenation of carbon oxides. Suitable catalysts are boron halides, or chlorides of Al, Zn, and Fe, or their double compounds. Polymerization may be carried out in the gas phase or in the liquid phase using pressure to liquefy the olefines or in the presence of an inert diluent, e.g. a saturated benzine. The catalyst is preferably decomposed, as soon as a polymer of desired viscosity is obtained, by treatment with water or dilute caustic alkali. The oils may then be fractionated. The crude products or their fractions are preferably first hydrogenated, using increased temperature and pressure, and nickel catalysts, up to 5 per cent of caustic alkali is added, and the products distilled with superheated steam. A subsequent distillation in vacuo may be effected. Products suitable as insulating oils are obtained, in addition to lower boiling fractions which can be used as benzines or Diesel oils. In an example, a gas obtained by reaction of CO and H2, containing chiefly butylenes, amylenes, and propylene, together with paraffins, is moistened, mixed with BF3, and passed at 10-15 DEG C. down a packed tube. The liquid product is treated with caustic potash, passed over a nickel catalyst in an atmosphere of hydrogen at 140-150 DEG C. and 200 atmos., and distilled in superheated steam after addition of solid KOH.