GB618674A - Improvements in or relating to the catalytic polymerization of hydrocarbons - Google Patents

Abstract

A catalyst for olefin polymerization comprises an oxide of iron, nickel or cobalt activated by pre-treatment at 400-700 DEG C. for at least 1/2 hr. with a gas containing free oxygen. Nickel oxide on kieselguhr, alumina, charcoal or the like is preferred. Basic nickel carbonate may be precipitated on kieselguhr, reduced with hydrogen at 300-400 DEG C., and oxidized with oxygen-nitrogen containing 1-10 per cent oxygen of which a deficiency or excess may be used. Alternatively, the carbonate may be converted directly to oxide by heating in air or nickel nitrate decomposed to oxide and then activated. Polymerization is effected in liquid or gas phase. Diluents, especially higher boiling normal or cyclo-paraffins, may be present. Polymerization activity is increased by addition of alkali or alkaline earth metals or their alloys or amalgams, preferably in liquid state. Contact times may be 30 secs. to 12 hrs. In examples, a catalyst prepared by precipitating basic nickel carbonate on kieselguhr, reducing in hydrogen at 400 DEG C., oxidizing with a 2 per cent oxygen in nitrogen mixture at 600 DEG C., and cooling in nitrogen is charged, alone or with purified pentane or pentane and sodium, to an autoclave in a nitrogen atmosphere, heated to 105-110 DEG C. and used for ethylene polymerization. Catalysts prepared by decomposing the nickel carbonate on kieselguhr or nickel nitrate on activated alumina in oxygen-nitrogen mixtures, followed by activation are used similarly.ALSO:Olefins of two to five carbon atoms are polymerized to higher aliphatic olefins by passing at 0-225 DEG C., preferably 50-150 DEG C., and a pressure between atmospheric and 2000 p.s.i., in contact with a catalyst comprising an oxide of iron, nickel or cobalt, activated by pre-treatment at 400-700 DEG C. for at least 1/2 hour with a gas containing free oxygen. Nickel oxide on kieselguhr, alumina, charcoal or the like is preferred. Basic nickel carbonate may be precipitated on kieselguhr, reduced with hydrogen at 300-400 DEG C., and oxidized with oxygen-nitrogen containing 1-10 per cent oxygen of which a deficiency or excess may be used. Alternatively, the carbonate may be converted directly to oxide by heating in air or nickel nitrate decomposed to oxide and then activated. Polymerization is effected in liquid or gas phase. Diluents, especially higher boiling, normal or cyclo paraffins, may be present. The charge may be purified with nickel on kieselguhr at 200 DEG C., followed by caustic soda on asbestos or with a metal forming alkyl derivatives reactive with water, such as sodium, mixed with an iron group metal at 50-150 DEG C. as described in U.S.A. Specification 2,378,969. Polymerization activity is increased by addition of alkali or alkaline-earth metals, or their alloys or amalgams, preferably in liquid state. Contact times may be 30 secs. to 12 hours. The products range from dimers to viscous oils or waxes with a minimum of chain branching. They may be separated into fractions which can be polymerized with halides to lubricants, hydrogentated to motor fuels or depolymerized partially and the products polymerized or used to alkylate aromatics or isoparaffins. In examples, a catalyst prepared by precipitating basic nickel carbonate on kieselguhr, reducing in hydrogen at 400 DEG C., oxidizing with a 2 per cent oxygen in nitrogen mixture at 600 DEG C., and cooling in nitrogen, is charged alone or with purified pentane or pentane and sodium, to an autoclave, in a nitrogen atmosphere, heated to 105-110 DEG C., and purified ethylene passed in to maintain a pressure of 600 p.s.i. over 2 hours when the polymer is separated into butene-1 and -2 and higher fractions. A pelleted catalyst at 50 DEG C. is treated with a stream of purified ethylene giving merely butene-1 and -2. Catalysts prepared by decomposing the nickel carbonate on kieselguhr or nickel nitrate on activated alumina in oxygen-nitrogen mixtures, followed by activation are used similarly. Propylene is polymerized with an activated nickel oxide on kieselguhr in presence of sodium and pentane at 110-115 DEG C. and a maximum pressure of 1400 p.s.i.ALSO:Olefins of two to five carbon atoms are polymerized to higher aliphatic olefins by passing, at 0-225 DEG , preferably 50-150 DEG C., and a pressure between atmospheric and 2000 p.s.i., in contact with a catalyst comprising an oxide of iron, nickel or cobalt activated by pretreatment at 400-700 DEG C. for at least 1/2 hr. with a gas containing free oxygen. Nickel oxide on kieselguhr, alumina charcoal or the like is preferred. Basic nickel carbonate may be precipitated on kieselguhr, reduced with hydrogen at 300-400 DEG C., and oxidized with oxygen-nitrogen containing 1-10 per cent oxygen of which a deficiency or excess may be used. Alternatively, the carbonate may be converted directly to oxide by heating in air or nickel nitrate decomposed to oxide and then activated. Polymerization is effected in liquid or gas phase. Diluents, especially higher boiling normal or cyclo-paraffins, may be present. The charge may be purified with nickel on kieselguhr at 200 DEG C., followed by caustic soda on asbestos or with a metal forming alkyl derivatives reactive with water, such as sodium, mixed with an iron group metal at 50-150 DEG C., as described in U.S.A. Specification 2,378,969. Polymerization activity is increased by addition of alkali or alkaline-earth metals or their alloys or amalgams, preferably in liquid state. Contact times may be 30 secs. to 12 hrs. The products range from dimers to viscous oils or waxes with a minimum of chain branching. They may be separated into fractions which can be polymerized with halides to lubricants, hydrogenated to motor fuels or depolymerized partially and the products polymerized or used to alkylate aromatics or isoparaffins. In examples, a catalyst prepared by precipitating basic nickel carbonate on kieselguhr, reducing in hydrogen at 400 DEG C., oxidizing with a 2 per cent oxygen in nitrogen mixture at 600 DEG C. and cooling in nitrogen, is charged alone or with purified pentane or pentane and sodium to an autoclave, in a nitrogen atmosphere, heated to 105-110 DEG C., and purified ethylene passed in to maintain a pressure of 600 p.s.i. over 2 hrs. when the polymer is separated into butene-1 and -2 and higher fractions. A pelleted catalyst at 50 DEG C. is treated with a stream of purified ethylene giving mainly butene-1 and -2. Catalysts prepared by decomposing the nickel carbonate on kieselguhr or nickel nitrate on activated alumina in oxygen-nitrogen mixtures, followed by activation are used similarly. Propylene is polymerized with an activated nickel oxide on kieselguhr in presence of sodium and pentane at 110-115 DEG C. and a mazimum pressure of 1400 p.s.i.