Basf Aktiengesellschaft

Basf Aktiengsellschaft

Elmar Frommer

Erwin Thomas

Otto-Alfred Grosskinsky

Franz-Josef Weiss

Josef Ritz

Hugo Fuchs

Guenter Herrmann

Gunther Rapp, Deceased

Siegfried Winderl

Wolfgang Habermann

Wolfgang Reiss

Peter Hammes

Juergen Paetsch

Peter Magnussen

Uwe Brand

Peter Thoma

Klaus Kartte

Guenther Rapp

Ruediger Schmitz

Ernst Deuker

Guenther Rapp, Deceased

Alfred-Otto Grosskinsky

Aqueous solutions of hydroxylamine are prepared from aqueous hydroxylammonium salt solutions by electrodialysis by a method in which the aqueous hydroxylammonium salt solution is fed into the middle zone of an electrolysis cell, which is divided into a cathode zone, an anode zone and a middle zone by means of semipermeable membranes, and is electrolyzed, and the catholyte used is an alkali metal hydroxide solution containing ammonia and/or amines.

Preparation of aqueous hydroxylamine solutions

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

Stabilized solutions of hydroxylamine or its salts in water or alcohols,

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

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

Stabilized solutions of hydroxylamine or its salts

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.

The hydrogenation of carboxylic acids having 6 or less C atoms, as obtained as by-products of cyclohexane oxidation, to give corresponding diols is improved by the addition of a small amount of phosphoric acid or a phosphoric ester before hydrogenation.

Preparation of diols

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 &lt;2.0 in the last reaction zone.

Continuous preparation of hydroxylammonium salts

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.

Preparation of hydroxylammonium salts

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.

A process for removing nitrous oxide from exit gases which contain this compound and have been obtained in the preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in an aqueous solution of a mineral acid, in the presence of a suspended noble metal catalyst, wherein the exit gases are washed with water.

Removal of nitrous oxide from exit gases containing this compound during

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.

Process for obtaining caprolactam by cleaving caprolactam oligomers

In a process for continuously extracting caprolactam from an aqueous solution, containing caprolactam and its oligomers, with organic solvents, by introducing the aqueous solution into the upper part of an extraction zone and organic solvents into the lower part, and taking off a solution of caprolactam in organic solvents at the upper end and an aqueous phase containing caprolactam oligomers at the lower end, the improvement that liquid aromatic hydrocarbons are used and the extraction is carried out at a pH of from 2.0 to 6.0.

Continuous extraction of caprolactam from an aqueous solution containing

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.

Purification of caprolactam

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.

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Ludwigshafen, Germany

Elmar Frommer