Abstract: Solutions of molecular oxygen in liquid hydrocarbons are prepared by bringing a liquid hydrocarbon into contact with molecular oxygen under superatmospheric pressure in a vertical absorption zone, by a process in which(a) a layer of water is maintained at the lower end of the absorption zone,(b) molecular oxygen is passed into the layer of water,(c) a liquid hydrocarbon is fed in above the layer of water,(d) the finely divided molecular oxygen rising from the layer of water is passed upward together with the liquid hydrocarbon at from 0.degree. to 50.degree. C., with thorough mixing in the absorption zone, with the proviso that no cohesive gas phase is formed, and(e) the solution of molecular oxygen in the liquid hydrocarbon is discharged in the upper part of the absorption zone.

Abstract: Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing the lactone of the formula ##STR1## and their preparation.

Abstract: Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing 8-hydroxyquinaldines, and their preparation.

Abstract: Oxygen-containing compounds are prepared by oxidizing a hydrocarbon in the liquid phase with a gas containing molecular oxygen, at elevated temperatures and under superatmospheric pressure, by a continuous process in which the said gas is fed into the liquid reaction mixture, in a downward direction, at several points along the reaction zone via nozzle apertures, so that it emerges at each nozzle aperture with a velocity of from 0.01 to 1 m/sec in an amount of from 0.001 to 10 liters per second per nozzle aperture, and the said reaction mixture is brought into substantially uniform contact with the gas containing molecular oxygen, over the volume of the reaction zone.

Abstract: Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing hydroxyanthraquinones, and their preparation.

Abstract: Stabilized solutions of hydroxylamine or its salts, containing anthocyans of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen, hydroxyl or C.sub.1 -C.sub.4 -alkoxy and X is an anion of a strong mineral acid, and their preparation.

Abstract: An improved process for the continuous preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended noble metal catalyst at an elevated temperature in several reaction zones connected in series, wherein the improvement comprises maintaining a pH of <2.0 in the last reaction zone.

Abstract: Hydroxylammonium salts are prepared by an improved process, wherein nitric oxide is reduced catalytically with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended supported platinum catalyst and at elevated temperatures, and wherein the improvement comprises avoiding the formation of foam at the surface of the reaction mixture.

Abstract: A process for the preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in a dilute aqueous solution of a mineral acid, in the presence of a suspended supported platinum catalyst, at elevated temperatures, wherein the reaction is carried out in a conventional manner, in one or more reaction zones, under superatmospheric pressure, and the exit gases produced are let down to a lower pressure, and are reacted, in a downstream reaction zone, with the reaction mixture, containing hydroxylammonium salt, the ammonium salt, the supported platinum catalyst and residual mineral acid, from the upstream reaction zone or zones, or with a fresh aqueous solution of the mineral acid, which contains the supported platinum catalyst in suspension.

Abstract: In a process for obtaining caprolactam by cleaving caprolactam oligomers by passing them through an alumina catalyst bed at an elevated temperature, the improvement that the oligomers are introduced, as liquid or solid, into a fluidized bed of alumina and are cleaved at from 290.degree. to 400.degree. C. in the presence of steam.

Abstract: A process for purifying caprolactam, which has been obtained by a Beckmann rearrangement, by extracting crude caprolactam with solvents, distilling the extract in the presence of alkali, and isolating pure caprolactam, wherein, in a first stage, caprolactam is distilled from the alkaline distillation residue at a bottom temperature of 130.degree.-160.degree. C., and is recycled to the distillation stage, the residue thus obtained is distilled, in a second stage, at a bottom temperature of 140.degree.-180.degree. C., and the distillate is treated with strongly acidic agents in a third stage and is then recycled to the extraction stage.

Abstract: A process for the continuous preparation of .epsilon.-caprolactam by Beckmann rearrangement of cyclohexanone-oxime, dissolved in a solvent which is inert toward oleum and is immiscible with oleum and water, at an elevated temperature, with removal of the heat of rearrangement by evaporation of the solvent, wherein oleum containing caprolactam is circulated successively through a conveying zone, a mixing zone, a boiling zone and a separating zone, upstream of the conveying zone oleum is added at the rate at which it is consumed, in the mixing zone cyclohexanone-oxime dissolved in solvent is added under turbulent conditions, in the boiling zone the heat of rearrangement is removed in a conventional manner by evaporating the solvent and recycling the condensate, and in the separating zone the reaction mixture is separated into a solvent phase, from which solvent is withdrawn at the rate at which the phase is formed, and a caprolactam-containing oleum phase, which is removed at the rate at which it is formed.

Abstract: An improved process for producing adipic acid from the acidic wash waters which arise in the process for oxidizing cyclohexane with air, by treatment with nitric acid at from 10.degree. to 50.degree. C., with removal of the heat of reaction by external cooling, wherein the reaction mixture is led, at a flow velocity of at least 2.0 m/sec, as a thin layer spirally in counter-current to the coolant, under conditions which do not perturb the flow of the reaction mixture.

Abstract: Olefinically unsaturated aliphatic or cycloaliphatic hydrocarbons are manufactured by bringing alkanecarboxylic acids of 3 to 20 carbon atoms, alkanedicarboxylic acids of 4 to 20 carbon atoms or 5-membered or 6-membered cycloalkanecarboxylic acids or their alkyl, cycloalkyl, aralkyl or phenyl esters, in the gas phase, at from 250.degree. to 800.degree. C., into contact with catalysts in which the active composition consists of boron trioxide, boric acid and/or boron nitride, together with one or more of the oxides of aluminum, silicon, tin, lead, titanium and zirconium.