Abstract: An improved method for the preparation of cyclohexanol and/or cyclohexanone from benzene. Cyclohexanol and/or cyclohexanone is prepared by the steps of hydrogenating benzene to form a hydrogenation reaction mixture containing cyclohexene, unreacted benzene, and by-product cyclohexane, hydrating cyclohexene thus obtained to form a hydration reaction mixture containing cyclohexanol, unreacted benzene and by-product cyclohexane and/or oxidating this cyclohexene to form an oxidation reaction mixture containing cyclohexanone, unreacted benzene and by-product cyclohexane, recovering from said hydration reaction mixture the cyclohexanol product and/or from said oxidation reaction mixture the cyclohexanone product, and an organic phase containing unreacted benzene and by-product cyclohexane, and recycling unconverted benzene to the benzene hydrogenation step.

Abstract: The invention relates to a method for removal of alkali metal carboxylates from mixtures which contain a cycloalkanone and a cycloalkanol, in particular cyclohexanone and cyclohexanol, and which have been obtained in oxidation in the liquid phase of the corresponding cycloalkane with gas containing molecular oxygen.According to the invention, alkali metal carboxylates are removed from such mixtures containing a cycloalkanone and a cycloalkanol by washing the mixture with an aqueous acid solution, in particular an aqueous solution of carboxylic acid with 1-6 carbon atoms per molecule.The invention provides a solution to the problem of the so-called alkali entrainment, which leads to loss of cycloalkanone owing to condensation into undesired high-boiling by-products in the following distillation for gaining pure cycloalkone. This substantial loss is prevented by the method according to the invention.

Abstract: There is disclosed an improved process for oxidizing cyclohexane to produce a reaction mixture containing cyclohexyl hydroperoxide and decomposing the cyclohexyl hydroperoxide to form a mixture containing cyclohexanone and cyclohexanol comprising using in the oxidation step and/or the decomposition step as a catalyst a transitional metal complex of certain 1,3-bis(pyridylimino)isoindolines.

Abstract: An oxidizable hydrocarbon is oxidized in a reaction zone at elevated temperature in the presence of a liquid reaction medium by introducing the hydrocarbon and a feed stream containing molecular oxygen to the reaction zone under conditions sufficient to oxidize at least a portion of the hydrocarbon; withdrawing at least a portion of the liquid reaction medium from the reaction zone; passing at least a portion of the withdrawn liquid reaction medium to an oxygen injection zone located external to the reaction zone; contacting the liquid in said oxygen-injection zone with a gas stream containing molecular oxygen under conditions sufficient to form a two-phase gas/liquid mixture; and passing said two-phase gas/liquid mixture to the reaction zone as the feed of molecular oxygen thereto.

Abstract: A process for working up reaction mixtures containing cyclohexanol and cyclohexanone, which have been obtained by oxidizing cyclohexane with molecular oxygen or gases containing molecular oxygen, in the liquid phase, at from 130.degree. to 200.degree. C. under a pressure of from 5 to 25 bars, working-up being effected by treatment with aqueous solutions of an alkali metal hydroxide and/or alkali metal carbonate in two stages, the fresh aqueous alkali metal hydroxide and/or alkali metal carbonate solution being fed to the second stage and the separated-off spent alkali being brought into contact with fresh reaction mixture in the first stage. The treatment in the first stage is carried out in the presence of inert gases and the inert gases are separated off before the second stage.