GB437315A - Improvements in methods of obtaining ketones from alcohols - Google Patents

Abstract

Ketones are prepared by the treatment of alcohols containing more than one carbon atom with catalysts comprising a mixture of easily reducible and difficultly reducible oxides and a metal halide. Such catalysts are described in U.S.A. Specifications 1,625,924, 1,625,927, 1,625,928, and 1,625,929 and preferably contain zinc and chromium oxides and a halide such as zinc chloride. Suitable catalysts may be made (1) by adding zinc oxide to a solution of chromium nitrate zinc chloride and ferric nitrate evaporating to dryness and igniting and then adding some zinc chloride solution; (2) by adding zinc oxide to a solution of cobalt nitrate and then ammonia separating and drying the precipitate and adding zinc chloride solution; (3) by mixing zinc and copper oxides and adding a mixture of cuprous chloride and dextrin solution; (4) by precipitating ferric nitrate solution with ammonia mixing the precipitate with zinc oxide drying and adding ferric chloride. The conversion of the alcohols into ketones may be effected in the presence of water vapour or under reduced pressure. In an example the vapour of 10 per cent aqueous ethyl alcohol is passed at 400 DEG C. over the catalyst prepared by the first method. The vapour is preferably preheated. The reaction temperature may be 250--650 DEG C. The production of acetone from ethyl or isopropyl alcohol, diethyl ketone from propyl alcohol, dipropyl ketone from butyl alcohol, a mixture of diethyl, dipropyl and ethyl propyl ketones from propyl and butyl alcohols and corresponding ketones from secondary butyl, amyl and other alcohols is mentioned. The catalysts may be regenerated when necessary by treatment with air or oxygen at 450--600 DEG C.ALSO:Ketones are prepared by the treatment of alcohols containing more than one carbon atom with catalysts comprising a mixture of easily reducible and difficultly reducible oxides and a metal halide. Such catalysts are described in U.S.A. Specifications 1,625,924, 1,625,927, 1,625,928, and 1,625,929 and preferably contain zinc and chromium oxides and a halide such as zinc chloride. Suitable catalysts may be made (1) by adding zinc oxide to a solution of chromium nitrate, zinc chloride and ferric nitrate evaporating to dryness and igniting and then adding some zinc chloride solution; (2) by adding zinc oxide to a solution of cobalt nitrate and then ammonia separating and drying the precipitate and adding zinc chloride solution; (3) by mixing zinc and copper oxides and adding a mixture of cuprous chloride and dextrin solution; (4) by precipitating ferric nitrate solution with ammonia, mixing the precipitate with zinc oxide, drying and adding ferric chloride. The conversion of the alcohols into ketones may be effected in the presence of water vapour or under reduced pressure. The reaction temperature may be 250--650 DEG C. The production of acetone from isopropyl alcohol, and corresponding ketones from secondary butyl, amyl and other alcohols is mentioned. The catalysts may be regenerated when necessary by treatment with air or oxygen at 450--600 DEG C.