GB435858A - Manufacture of alkyl chlorides and/or alkyl bromides from olefines or mixtures containing olefines - Google Patents

Abstract

Alkyl chlorides and bromides are made by reacting the halogen acids with olefines in presence of an adsorbent "hydrous metal oxide gel," i.e. a partially or nearly dehydrated mass obtained from a hydrogel or gelatinous precipitate. The oxides of cerium, vanadium, chromium, molybdenum, tungsten, uranium, beryllium, copper, zinc, cadmium, aluminium, bismuth, germanium, tin, manganese, iron, cobalt, and nickel may be obtained in this condition, and the adsorbent oxides of copper, zinc, cadmium, aluminium, bismuth, tin, manganese, iron, nickel and cobalt are especially suitable. The adsorbent oxide may be used in association with an inert adsorbent by simply mixing the materials or by simultaneous chemical production. An alumina gel may be made by adding aluminium chloride to a sodium aluminate solution so that the mixture, which is maintained below 10 DEG C., is still alkaline. The mixture is allowed to stand for 24 hours and is then placed in a vacuum filter; the mass is broken up, washed, dried at 30 DEG C. in a current of air and then at 250--300 DEG C. Mixed catalysts may be made by replacing the aluminium chloride by an equivalent solution of iron, vanadium or cerium. Alternatively, aluminium sulphate solution is precipitated with soda, ammonia or an organic base such as ethanolamine, preferably at 0 DEG C. or lower, for instance at -5 DEG C., the mixture being alkaline, and 3 parts of the washed precipitate are mixed with 97 parts of silica hydrogel made from sodium silicate and hydrochioric acid. A mixed catalyst may also be prepared by treating a natural or artificial zeolite with decinormal hydrochloric acid to remove the alkali metal. Another mixed catalyst is prepared by adding ammonia to a solution containing stannic chloride and sodium tungstate, the washed hydrogel being dried at 150--200 DEG C. In producing the alkyl halides, the higher olefines being more reactive than the lower, and hydrobromic acid being more reactive than hydrochloric, a mixture of ethylene and butylene may be treated first with hydrochloric acid to produce secondary butyl chloride, and then with hydrobromic acid to produce ethyl bromide. The reaction may be effected at elevated temperature, with or without pressure; for instance at 100 DEG C. and atmospheric pressure, and the process may be continuous or not, when the olefine is relatively concentrated, the product may be separated by condensation, but when dilute, the product may be adsorbed in suitable material such as a hydrous oxide gel or absorbed in oil. Specifications 353,032 and 414,766 are referred to. According to the Provisional Specification dehydrated or partially dehydrated natural and artificial zeolites are suitable catalysts.ALSO:Alkyl chlorides and bromides are made by reacting the halogen acids with olefines in presence of an adsorbent " hydrous metal oxide gel" i.e. a partially or nearly dehydrated mass obtained from a hydrogel or gelatinous precipitate. The oxides of cerium, vanadium, chromium, molybdenum, tungsten, uranium beryllium, copper, zinc, cadmium, aluminium, bismuth, germanium, tin, manganese, iron, cobalt, and nickel may be obtained in this condition, and the adsorbent oxides of copper, zinc, cadmium, aluminium, bismuth, tin, manganese, iron, nickel and cobalt are especially suitable. The adsorbent oxide may be used in association with an inert adsorbent by simply mixing the materials or by simultaneous chemical production. An alumina gel may be made by adding aluminium chloride to a sodium aluminate solution so that the mixture which is maintained below 10 DEG C., is still alkaline. The mixture is allowed to stand for 24 hours and is then placed in a vacuum filter; the mass is broken up, washed, dried at 30 DEG C., in a current of air and then at 250--300 DEG C. Mixed catalysts may be made by replacing the aluminium chloride by " equivalent solution " of iron, vanadium, or cerium. Alternatively aluminium sulphate solution is precipitated with soda, ammonia or an organic base such as ethanolamine, preferably at 0 DEG C., or lower, for instance at --5 DEG C., the mixture being alkaline, and 3 parts of the washed precipitate are mixed with 97 parts of silica hydrogel made from sodium silicate and hydrochloric acid. A mixed catalyst may also be prepared by treating a natural or artificial zeolite with decinormal hydrochloric acid to remove the alkali metal. Another mixed catalyst is prepared by adding ammonia to a solution containing stannic chloride and sodium tungstate, the washed hydrogel being dried at 150--200 DEG C. Specifications 353,032, and 414,766, [Group IV], are referred to. According to the Provisional Specification dehydrated or partially dehydrated natural and artificial zeolites are suitable catalysts.