Basf Aktiengesellschaft

Basf Se Corporation

Ulrich Penzel

Eckhard Stroefer

Wolfgang Mackenroth

Hans Volkmar Schwarz

Ekkehard Schwab

Filip Nevejans

Volker Scharr

Hans-Juergen Pallasch

Martin Sohn

Dominic Vanoppen

Eckhard Str&ouml;fer

Steffen Oehlenschlaeger

Peter Van Den Abeel

Hartwig Voss

Kai Thiele

Andreas Wölfert

Andreas Raichle

Heiner Schelling

Stefan Maixner

Samuel Neto

Matthias Eiermann

Jon S Speier

Filip Deberdt

Johannes Buettner

Johannes Jacobs

Peter Zehner

Torsten Mattke

Carsten Knoesche

Andreas Woelfert

Andreas Brodhagen

Joachim Pfeffinger

Michael Bock

Eckhard Ströfer

Frank Poplow

Joana Coelho Tsou

Martin Reif

Georg Krug

Steffen Oehlenschläger

Jan Jacobs

Gunter Georgi

Konrad Morgenschweis

Olaf Schweers

Bernd Weidner

Wilfried Seyfert

Stefanie Haase

Michael Sander

Jan D Jacobs

Holgar Braunsberg

Markus Maurer

Frederik Van Laar

Dietrich Tittelbach-Helmrich

Holger Allardt

Michael Zoellinger

Tsung-Chieh Cheng

Ruediger Fritz

Anne-Kathrin Merten

Kerstin Heinen

Ralf B&ouml;hling

Thomas A Grzanka

Johannes Adam

Thomas Beuermann

Joern Mueller

J&ouml;rn M&uuml;ller

Dieter St&uuml;tzer

Rene Leuthold

Dieter Starosta

Willy Van Pee

Hilmar Boesel

Dietmar Peisker

Fritz N&auml;umann

Klaus Werner

J&uuml;rgen Dosch

Christian Tragut

Holger Braunsberg

Frederick Van Laar

Gerald Molz

Juergen Dahlhaus

William Portwood

Uwe Storck

Dave Beckwith

Dirk Hablawetz

Johannes Büttner

Myung Un Won

The present invention relates to a continuous process for preparing at least one aromatic amine by hydrogenation of at least one nitroaromatic by means of hydrogen, where a liquid phase comprising at least the aromatic amine and a gas phase comprising at least hydrogen are present, in the presence of a catalyst suspended in the liquid phase at a temperature of from 50 to 250&#xb0; C. and a pressure of from 5 to 50 bar, wherein the pressure in the reactor is kept essentially constant by continuous adaptation of the amount of hydrogen fed to the reactor, the total amount of hydrogen fed to the reactor is monitored and the introduction of the at least one nitroaromatic is interrupted if the hydrogen uptake in the reactor is not at least 50 mol % of the amount of hydrogen required for stoichiometric reaction of the at least one nitroaromatic to form the at least one aromatic amine.

Monitoring of the stoichiometric ratio in the reaction of nitroaromatics with hydrogen

The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, if appropriate in the presence of at least one inert medium, in which the amine and the phosgene are first mixed in a mixing chamber () to give a reaction mixture and the reaction mixture is fed to a reactor, the amine being added through an orifice () arranged coaxially to the mixing chamber () and the phosgene being added through feed orifices () in at least two planes () arranged at right angles to the axis () of the mixing chamber (), or the phosgene being added through the orifice () arranged coaxially to the mixing chamber and the amine through the feed orifices () in at least two planes () arranged at right angles to the axis () of the mixing chamber (). At least one plane () is arranged upstream and at least one plane () downstream of the orifice () arranged coaxially to the mixing chamber () in main flow direction of the reaction mixture. The mean residence time of the reaction mixture in the mixing chamber () is not more than 20 ms.

Process for preparing aromatic isocyanates

The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and recirculation of at least a portion of the solvent streams.

Process for the production of isocyanates, preferably diisocyanates and polyisocyanates with solvent recirculation

The invention relates to a process for the continuous preparation of toluenediamine by liquid-phase hydrogenation of dinitrotoluene by means of hydrogen in the presence of a suspended, nickel-comprising catalyst in a reactor with a product isolation unit downstream of the reactor to give a product output from the reactor comprising a liquid phase comprising toluenediamine and dinitrotoluene, in which the nickel-comprising catalyst is suspended, wherein the concentration of dinitrotoluene in the liquid phase of the product output from the reactor in the region between the reactor and the downstream product isolation unit is set to a value in the range from 1 to 200 ppm by weight, based on the total weight of the liquid phase of the product output from the reactor.

Process for preparing toluenediamine by hydrogenation of dinitrotoluene

The invention relates to a method of measuring entry of water and resulting corrosion in plants for producing isocyanates by reacting phosgene with one or more primary amines in a solvent. The invention further relates to an apparatus for producing such isocyanates, in the work-up section of which probes for monitoring corrosion are arranged in defined places.

Method of measuring entry of water into phosgene-conducting plants

A process is proposed for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating toluene with nitrating acid, which comprises

Process for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating of toluene with nitrating acid

The invention relates to a process for preparing polyisocyanates by reacting organic amines with phosgene, wherein the reaction is carried out in at least three stages, with the first stage being carried out in a mixing apparatus, the second stage in at least one residence apparatus and the third stage in at least one separation apparatus and the pressure in each successive stage being lower than that in the previous stage.

Method for the continuous production of isocyanates

The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Method for producing aromatic amines or aliphatic amino alcohols

The invention relates to a process for the partial or complete separation of a mixture comprising hydrogen chloride and phosgene, possibly solvents and possibly low boilers and inerts as are typically obtained in the preparation of isocyanates by reaction of amines with phosgene, which comprises firstly carrying out a partial or complete condensation of phosgene, then a distillation or stripping step in a column to remove the hydrogen chloride from the bottom product phosgene and subsequently a scrub of the top product hydrogen chloride by means of the process solvent to absorb the phosgene in the process solvent. An after-purification by means of adsorption on activated carbon or by another suitable method can subsequently be carried out to remove solvent residues.

Separation of a substance mixture consisting of hydrogen chloride and phosgene

The invention relates to a process for preparing isocyanates by reaction of amines with phosgene in the presence of inert organic solvents in a reactor and subsequent work-up of the reaction mixture leaving the reactor, wherein the solvent is separated off in a two-stage or multistage, preferably two-stage, distillation process in which the solvent is separated off at a pressure of 0.1-15 bar in a first apparatus and at 1-900 mbar in a second apparatus or further apparatuses, with the heat of condensation of the solvent vapor from the first apparatus being used for partial or complete vaporization of solvent in the second apparatus.

Method for separating out solvent from a reaction mixture resulting from an isocyanate synthesis and for purifying this solvent

The present invention provides a process for hydrogenating aromatic nitro compounds to the corresponding amines in the presence of hydrogenation catalysts, which comprises using hydrogenation catalysts in which nickel and platinum are present on a support in the form of an alloy having an atomic ratio of nickel to platinum in the alloy of between 30:70 and 70:30.

Method for the production of amines

A catalyst comprising nickel on a TiOsupport is obtainable by coprecipitation of It is used, in particular, for the hydrogenation of nitroaromatic compounds.

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The invention relates to a process for distillatively preparing TDA from a reactant stream comprising TDA, high boilers and low boilers in a dividing wall column in which a dividing wall is disposed in the longitudinal direction of the column to form an upper combined column region (), a lower combined column region (), a feed section () having a rectifying section () and stripping section (), and also a withdrawal section () having a rectifying section () and stripping section (), which comprises the following steps:

Method for the distillative recovery of toluylenediamine

A process for preparing methylenedianiline by reacting aniline with formaldehyde in the presence of acid catalysts comprising, in a semicontinuous process, introducing aniline with or without acid catalyst, feeding formaldehyde with or without acid catalyst through a mixing element into a circuit in which aniline with or without acid catalyst and with or without previously added formaldehyde is circulated and, after feeding in at least 50% of the total amount of formaldehyde to be fed in, heating the reaction mixture to a temperature above 75&#xb0; C. In addition, the invention relates to a process for preparing polyisocyanates by phosgenation of amines obtainable in this manner and to the polyisocyanates obtainable by this process.

Process for preparing methylenedianiline and methylenebis (phenylisocyanate)

The invention provides a process for preparing amines by catalytic hydrogenation of nitroaromatics and subsequent removal of the catalysts from the reaction mixture, which contains at least one aromatic amine and water, which comprises carrying out the removal of the catalysts by means of membrane filtration, which is carried out at a pressure on the suspension side of from 5 to 50 bar, a pressure difference between the suspension side and the permeate side of at least 0.3 bar and a flux rate on the suspension side of from 1 to 6 m/s.

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Tettau, Germany

Ulrich Penzel