Basf Aktiengesellschaft

Ruediger Schmitz

Hugo Fuchs

Uwe Brand

Stefan Karbach

Erwin Thomas

Elmar Frommer

Guenter Herrmann

Gert Buerger

Klaus Kartte

Gerhard Frank

Ernst Deuker

Rudolph Hans Gath

Jost H Manegold

Guenther Rapp, Deceased

Alfred-Otto Grosskinsky

A process for working up mother liquors resulting from the preparation of adipic acid by oxidation of cyclohexanol or cyclohexanone or mixtures thereof with nitric acid entails removal of nitric acid by azeotropic distillation with water, heating the resulting melt at from 130.degree. to 180.degree. C. and then dissolving it in water, treating the aqueous solution with cation exchangers, subsequently again evaporating off the water and heating the resulting dicarboxylic acid melt at from 200.degree. to 240.degree. C. and then obtaining a mixture of dicarboxylic acids by distillation.

Workup of mother liquors resulting from the preparation of adipic acid

Reaction mixtures obtained by Beckmann rearrangement of cyclohexanone oxime with sulfuric acid or oleum are neutralized by a process which comprises the following steps:

Neutralization of reaction mixtures obtained by Beckman rearrangement of

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

A process for rapidly cooling gases which contain caprolactam vapor and which have been obtained by catalytic rearrangement of cyclohexanone-oxime in the gas phase in the presence of a supported catalyst containing boric acid, wherein a finely divided coolant at from 90.degree. to 200.degree. C. is fed into a cooling zone from above, gases which are at 330.degree.-400.degree. C. and contain caprolactam vapor are introduced radially at high speed through nozzle orifices over the downstream portion of the cooling zone, and are cooled to 100.degree.-200.degree. C. by thorough mixing with the finely divided coolant, and the cooled mixture is discharged.

Process for the rapid cooling of gases which contain caprolactam vapor

A process for processing polycaprolactam extraction liquors by evaporation of water and distillation of the residue in which the evaporation of water is carried out in a plurality of stages and the evaporation energy for the removal of the bulk of the water is taken from the heat liberated in the rearrangement of cyclohexanone oxime to caprolactam in oleum or sulfuric acid by using the extraction water for cooling the rearrangement mixture and utilizing the heat absorbed by the extraction water for the concentration of this extraction water by evaporation of water.

Processing polycaprolactam extraction liquors

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Lambsheim, Germany

Ruediger Schmitz