Bayer Intellectual Property Gmbh

Bayer Materialscience Ag

Covestro Deutschland Ag

Karl-Heinz Wilke

Michael Merkel

Peter Lehner

Thomas Knauf

Andre Lago

Hans-Georg Pirkl

Stephan Schubert

Knut Sommer

Franz-Ulrich Von Gehlen

Erwin Dieterich

Ido Schwarz

Thorsten Schmidt

Cliff Andre Peters

Susanne Buchholz

Holger Orzesek

Franz-Ulrich Gehlen

Susanne Bucholz

The present invention relates to a method for producing aromatic amines by the hydrogenation of aromatic nitro compounds. This method supplies aromatic nitro compounds and hydrogen to a reactor and contacts them with a hydrogenation catalyst; and stops the supply of aromatic nitro compounds and hydrogen to the reactor. The supply of aromatic nitro compounds and hydrogen to the reactor is stopped to ensure safe shutdown of the reactor.

Method for stopping a reaction during the production of aromatic amines from nitroaromatics

In a chemical reactor for heterogeneously catalyzed reaction of a fluid, comprising a holding device for catalyst particles and/or inert particles () through which the fluid flows, the side of the holding device lying upstream when viewed in the direction of flow of the fluid comprises knitted wire mesh fabric (), and the average clear mesh width of the knitted wire fabric () is smaller than the average particle size xof the particles (). The invention furthermore relates to a process for reaction of a fluid, wherein the reaction is carried out in a reactor according to the invention in the presence of heterogeneous catalyst particles () and the catalyst particles () are arranged in the holding device for catalyst particles (). The invention also provides the use of knitted wire mesh fabric () as a holding device for catalyst particles and/or inert particles () in chemical reactors.

Chemical reactor with knitted wire mesh fabric as a holding device for particles

The present invention relates to a catalyst comprising a ceramic support with a BET surface area of less than 40 m/g and (a) 1.0 to 100 g of at least one metal of groups 8 to 12 of the periodic table of the elements, (b) 1.0 g to 100 g of at least one metal of groups 4 to 6 and 12 of the periodic table of the elements and (c) 1.0 g to 100 g of at least one metal of groups 14 and 15 of the periodic table of the elements per liter of bulk volume of the ceramic support, wherein the catalyst is additionally doped with (d) potassium in a content of from 0.0050% by weight to 0.20% by weight, based on the total weight of the catalyst. The present invention also provides the use of such a catalyst in the catalytic gas phase hydrogenation of nitroaromatics.

Catalyst and method for producing aromatic amines in the gas phase

The invention relates to a process for the continuous preparation of aromatic amines by hydrogenation of the corresponding nitroaromatics in the presence of catalysts arranged in reaction spaces, in which an adiabatically operated reaction space RA is connected downstream of an isothermally operated reaction space RI and RA additionally also has a separate feed for the nitroaromatic to be hydrogenated, RI is fed with the nitroaromatic to be hydrogenated from the start to the end of the hydrogenation, and the product mixture emerging from RI is fed into RA from the start to the end of the hydrogenation, wherein RA can additionally be fed via the separate feed with the nitroaromatic to be hydrogenated.

Process for preparing aromatic amines

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

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Moers, Germany

Karl-Heinz Wilke