Basf Aktiengesellschaft

Uwe Brand

Hugo Fuchs

Klaus Kartte

Ruediger Schmitz

Ernst Deuker

Gerald Neubauer

Peter Horn

Elmar Frommer

Rudolph Hans Gath

Gerard Van Wauwe

Joachim Werther

Friedrich R Faulhaber

Jozef Oostvogels

Josef Beullens

Helmut Buchaeckert

Emile DeDecker

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

Water-immiscible solvents are removed from offgases containing same by washing with water-containing caprolactam.

Removal of water-immiscible solvents from offgases containing same

Caprolactam is obtained by cleaving oligomers of caprolactam by a process in which the oligomers, in a liquid or solid state, are introduced into a fluidized alumina bed and cleaved at from 290.degree. to 400.degree. C. in the presence of steam, and, in addition to the amount of inert gas required to fluidize the alumina bed, from 0.1 to 3 times this amount of inert gas is introduced above the fluidized bed.

Obtaining caprolactam by cleaving oligomers of caprolactam

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 the preparation of caprolactam wherein, in a first stage, cyclohexanone-oxime is vaporized, in the presence of inert gases, by bringing it into contact with a fluidized bed of inert solid particles at from 150.degree. to 250.degree. C., and the mixture of cyclohexanone-oxime vapor and inert gases is passed into a second stage, where the cyclohexanone-oxime is rearranged to caprolactam at from 230.degree. to 450.degree. C. over a supported catalyst, containing boron trioxide, in a fluidized bed.

Preparation of caprolactam

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

In a process for the preparation of .epsilon.-caprolactam by catalytic rearrangement of cyclohexanone-oxime in the gas phase at from 230.degree. to 450.degree. C. over a supported catalyst, containing boron trioxide, in a fluidized bed, wherein the catalyst is removed from the fluidized bed at the rate at which it becomes spent and is treated, in a fluidized state, with gases containing molecular oxygen at from 600.degree. to 900.degree. C., after which boron trioxide or boric acid is added to the fluidized catalyst, at from 300.degree. to 900.degree. C., before the catalyst is returned to the fluidized bed, the improvement that boron trioxide or boric acid of particle size from 0.05 to 1.5 mm is fed to the fluidized catalyst at one or more points.

Preparation of .epsilon.-caprolactam by catalytic rearrangement of

In a process for the continuous extraction of caprolactam from crude lactam by means of benzene in counter-current, in which crude lactam is fed into the upper part of an extraction zone and benzene into the lower part, a solution of caprolactam in benzene is taken off at the top and an aqueous solution containing impurities is taken off at the bottom, the improvement that water is additionally fed into the upper part of the extraction zone and a part of the aqueous solution, containing impurities, obtained at the bottom of the extraction zone is recycled into the extraction zone. Caprolactam is used for the manufacture of nylon.

Continuous extraction of caprolactam from crude lactam

A process for obtaining coarsely crystalline pure ammonium sulfate from reaction mixtures which have been obtained by Beckmann rearrangement of cyclohexanone-oxime with sulfuric acid or oleum, by neutralizing the mixtures with ammonia at an elevated temperature, with the addition of recycled ammonium sulfate mother liquor, the concentration being so chosen that during the neutralization no solid ammonium sulfate precipitates, separating the crude caprolactam from the ammonium sulfate solution, crystallizing ammonium sulfate by evaporating the ammonium sulfate solution under reduced pressure, separating off the crystallized ammonium sulfate and recycling the mother liquor to the neutralization stage. The neutralization is carried out at from 80.degree. to 115.degree. C. under autogenous pressure and the ammonium sulfate solution obtained after separating off the crude lactam is evaporated under a pressure of from 200 to 600 mm Hg while cooling to from 72.degree. to 101.degree. C.

Process for obtaining coarsely crystalline pure ammonium sulfate

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.

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Rosengarten, Germany

Uwe Brand