Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Covestro Deutschland Ag

Rainer Buse

Bill Brady

Friedhelm Steffens

Bernd Pennemann

Berthold Keggenhoff

Joachim Ritter

Jürgen Münnig

Gerd Greger

Aromatic amines are produced by catalytic hydrogenation of aromatic nitro compounds. The reaction mixture generated by this hydrogenation is then worked up by distillation in a manner which makes it possible to substantially free the amine of water with increased energy efficiency. Water free of amine and low boilers and the low boiling materials are also obtained.

Process for the preparation of aromatic amines

The invention relates to an energy efficient process for the distillative working-up of aqueous amine solutions that occur in the catalytic hydrogenation of nitroaromatic compounds. In this process, the amine is freed from water and also the water is obtained free from amine and low-boiling compounds and the concentrated low-boiling compounds are obtained.

Process for the distillative separation of aqueous amine solutions

The invention describes a stirring device made from a gassing stirrer and a liquid mixer or two liquid mixers, which are arranged on a shaft and each have a feed and at least one exit opening, wherein the exit openings of the gassing stirrer and of the liquid mixer or the liquid mixers are at a distance from one another, the ratio, a/d, of the distance, a, between the exit openings to the diameter, d, of the gassing stirrer or liquid mixer being 0.02 to 0.5 and the ratio, b/d, of the distance, b, between the outer edges to the diameter, d, of the gassing stirrer or liquid mixer being 0.01 to 0.4.

Stirring device and process for carrying out a gas-liquid reaction

Toluenediamine is produced and separated from by-products of the reaction by:

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Kö'ln, Germany

Rainer Buse