Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Covestro Deutschland Ag

Bayer Materialscience, LLC

Knut Sommer

Peter Lehner

Stefan Wershofen

Stephan Schubert

Ido Schwarz

Wolfgang Lorenz

Rainer Bruns

Hans-Georg Pirkl

Fritz Pohl

Richard Adamson

Amgad Salah Moussa

Andre Düx

Markus Dugal

Heinz-Herbert Müller

Karl-Heinz Wilke

Franz-Ulrich Von Gehlen

Andre Lago

Susanne Buchholz

Holger Orzesek

Benie Marotz

Franz-Ulrich Gehlen

Alexandra Groβe Böwing

Susanne Bucholz

Alexandra Grosse Böwing

The present invention relates to a process for producing diamines and polyamines of the diphenylmethane series (MDA) by reacting aniline and formaldehyde in the presence of an acid catalyst, wherein the aniline contains in total less than 0.5 wt. %, based on the total weight of aniline, of one or more compounds which contain at least one carbonyl group or of one or more compounds that are formed by reaction of these compounds which contain at least one carbonyl group with aniline.

Process for producing diamines and polyamines of the diphenylmethane series

The invention relates to a process for purifying aniline produced by gas-phase hydrogenation of nitrobenzene, by fractional condensation of the crude reaction product obtained in gaseous form so that at least two liquid process products, a partial condensate (PK) and a total condensate (TK), are obtained.

Process for purifying aniline from gas phase hydrogenations

Aromatic amines are produced by adiabatic hydrogenation of nitroaromatic compounds in the gas phase on one or more fixed catalysts. The nitroaromatic reactant is passed over the catalyst under pressure and at elevated temperature with hydrogen, water, optionally nitrogen and substantially in the absence of the aromatic amine produced from the nitroaromatic.

Process for producing aromatic amines

An isocyanate is produced by continuously reacting an amine with phosgene in the presence of an inert substance in the gas phase. In this process, a phosgene-containing stream and a stream containing both the amine and the inert substance are fed into a reactor. The molar ratio of the inert substance to the amino groups in the stream is greater than 0 but less than 45 mol %. This molar ratio changes by no more than 99% during a 20 minute period.

Method for producing isocyanates in the gas phase

Aromatic amines which have been obtained by reduction of aromatic nitro compounds are purified by mixing the crude amine obtained after phase separation with an aqueous, alkali metal hydroxide solution and subsequent distillation of this mixture over a distillation column. The distillation column has at least an upper and a lower rectifying part and a stripping part. The bottom product of the distillation column is partly to completely sluiced out and is partly evaporated in a main evaporator and at least one downstream re-evaporator and partly recycled back into the column.

Process for the purification of aromatic amines

Compounds containing phenolic hydroxy groups are removed from a gas stream which contains at least one aromatic amine generated during the gas-phase hydrogenation reaction of the corresponding nitroaromatic compounds with hydrogen, by adsorption on a basic solid.

Process for removing compounds containing phenolic hydroxy groups from aromatic amines

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Krefeld, Germany

Knut Sommer