Bayer Materialscience Ag

Covestro Deutschland Ag

Bayer Aktiengesellschaft

Bayer Materialscience, LLC

Covestro Intellectual Property Gmbh & Co. Kg

Dietmar Wastian

Tim Loddenkemper

Joachim Zechlin

Manfred Keller-Killewald

Michael Schelhaas

Christian Steffens

Anke Hielscher

Berthold Keggenhoff

Georg Ronge

Jürgen Münnig

Kai Verkerk

Katrin Joschek

Wilfried Pinke

Reinhard Halpaap

Thomas Knauf

Josef Sanders

Wolfgang Lorenz

Volker Michele

Thomas Schieb

Uwe Klingler

Martin Ehrig

Juergen Spriewald

Armin Schymura

Manfred Jautelat

Friedhelm Steffens

Gerhard Wegener

Bernd Pennemann

Andreas Karl Rausch

Hans-Georg Pirkl

Daniel Koch

Joachim Ritter

Gerhard Wiechers

Jan Busch

Jürgen Arras

Matthias Böhm

Jürgen Spriewald

Erwin Dieterich

Spotswood Miller

Juergen Muennig

Jürgen Kirsch

Ricardo Serra

Marcus Grünewald

Michel Haas

Bernd Rüffer

Achim Wildermuth

J&uuml;rgen Zimmerman

John F Gisch, Jr

Jesse Caravaggio

Kartin Joschek

Holger Conzelmann

Andreas Rausch

The present invention relates to a method for operating a plant for continuous production of an isocyanate by converting a primary amine A with phosgene P whilst maintaining, based on the amino groups of the primary amine, a stoichiometric excess of phosgene in the presence of a solvent L in the liquid phase, using a first, adiabatically operated reaction chamber and a second, isothermally operated reaction chamber. The method is characterised in that a combination of measures, in particular the maintenance of a sufficiently high starting pressure and a sufficiently high starting temperature, is applied in order to bring the plant back into the target state, standard operation, starting from a state of interruption to production.

Method for operating a plant for continuous production of an isocyanate

The present invention relates to a process for preparing an isocyanate by reacting a primary amine with phosgene, comprising I) providing an amine solution, II) providing a phosgene solution, III) mixing the amine solution with the phosgene solution in a mixing unit, followed by IV) further conversion in an adiabatically operated reaction zone and the removing of the gas phase formed as a result of the chemical reaction in a separation zone, V) expanding the remaining liquid phase in two or three stages, VI) further conversion of the liquid phase remaining after the last expansion stage in an indirectly heated reaction zone and VII) isolating the isocyanate from the reaction solution obtained therein.

Process for preparing an isocyanate by partly adiabatic phosgenation of the corresponding amine

A process for preparing an isocyanate by reacting a primary amine with phosgene. The process includes providing an amine solution and adjusting its temperature in a heat exchanger, providing a phosgene solution and adjusting its temperature in a heat exchanger, mixing the amine solution with the phosgene solution, further conversion in an adiabatically operated reaction zone and the removing of the gas phase formed as a result of the chemical reaction in a separation zone, expanding the remaining liquid phase, further conversion of the liquid phase remaining after expansion in an indirectly heated reaction zone, and isolating the isocyanate from the obtained reaction solution. The temperature in the reaction zone and the temperature in the separation zone is adjusted by fixing a target value of 110&#xb0; C. to 145&#xb0; C. for the temperature of the reaction mixture and using the actual temperature of the reaction mixture for closed-loop control of the temperature of the solution of the primary amine and/or of the temperature of the solution of phosgene.

Process for preparing an isocyanate by partly adiabatically operated phosgenation of the corresponding amine

The invention relates to the production of isocyanates by means of phosgenation of the corresponding primary amines in the gas phase, wherein the reactant flows of amine and phosgene are fed separately to a reactor through a pre-heated inert gas flow. Isocyanates within the sense of the invention are, in the broadest sense, all isocyanates whose corresponding amines can be substantially converted into the gas phase without decomposing, with the exception of 1,5-pentane diisocyanate.

Method for producing isocyanates

The invention relates to a method for producing 1,5-pentanediisocyanate (PDI) by reacting 1,5-pentanediamine (PDA) with phosgene in the gas phase.

Method for producing 1,5-pentanediisocyanate in the gas phase

The present invention relates to a continuous process for preparing a polyisocyanate, in which a polyamine and phosgene are first converted predominantly to carbamoyl chloride and amine hydrochloride and only in minor proportions to polyisocyanate, and a portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture thus obtained is recycled into the reaction with phosgene, wherein polyamine, phosgene and the carbamoyl chloride- and amine hydrochloride-containing reaction mixture are mixed intimately in a mixing unit. The portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture which is not recycled into the phosgenation is worked up to give the polyisocyanate.

Process for preparing polyisocyanates

A two-stage process for the preparation of organic isocyanates by reacting primary amines with phosgene in which: a) in a first stage, amine and phosgene are reacted in an adiabatically managed reaction, in which the temperature of reaction is restricted to values between 100 and 220&#xb0; C. by actively adjusting the absolute pressure in the reactor to values between 8 and 50 bar by decompression, and the temperature is held at values between 100 and 220&#xb0; C. until the stoichiometric conversion of phosgene has reached at least 80%; and then b) in a second stage, the reaction mixture from a) is decompressed to an absolute pressure of 1 to 15 bar and the reaction mixture is reacted further at temperatures between 90 and 240&#xb0; C., optionally with the introduction of heat.

Process for preparing polyisocyanates by the adiabatic phosgenation of primary amines

The invention relates to a mixer reactor of the rotor-stator type. This mixer reactor comprises a substantially rotationally symmetric housing which has a distributing chamber, a mixing chamber, a front plate that modifies the cross-section of the housing between these two chambers, and there are separate inlets into the mixing chamber for at least two substances and an outlet for removing the mixed material or product. The inlet for the first substance is provided in the axis of rotation of the mixing chamber. Two or more channels are aligned radially outward from this inlet, and the first substance is transported through these channels and into the mixing chamber. The inlet for the at least second substance is constructed in the form of a plurality of openings in the front plate, these inlet openings being are arranged rotationally symmetrically to the axis of rotation. Each of these inlet openings for the at least second substance has a corresponding pin which can be displaced in the axial direction.

Process and mixing unit for the preparation of isocyanates by phosgenation of primary amines

Processes for separating carbon monoxide from a hydrogen chloride-containing gas, which comprise reacting the carbon monoxide with chlorine to form phosgene and then optionally separating the phosgene from the hydrogen chloride-containing gas. The hydrogen chloride-containing gas that is used preferably derives from a phosgenation or isocyanate forming reaction.

Processes for separating carbon monoxide from a hydrogen chloride-containing gas

The present invention relates to a process for producing 5-nitro-3,4-dihydro-1(2H)-naphthalinone, 1,5-naphthalenediamine and 1,5-naphthalene diisocyanate, in which 4-(2-nitrophenyl)-n-butyronitrile is converted to 4-(2-nitrophenyl)-n-butyric acid.

Process for producing 5-nitro-3,4-dihydro-1(2H)-naphthalinone, 1,5-naphthalenediamine and 1,5-naphthalene diisocyanate

Process for producing 5-nitro-3,4-dihydro-1(H)-naphthalinone, 1,5-naphthalenediamine and 1,5-naphthalene diisocyanate

Process for producing 5-nitro-3,4-dihydro-1(2H)-naphthalinone, 1-5-naphthalenediamine and 1,5-naphthalene diisocyanate

The present invention is directed to a process for the isothermal nitration of aromatic organic compounds, wherein an aromatic organic compound is brought into contact and reacted with a mixture of sulfuric acid and nitric acid. The mixture of sulfuric acid and nitric acid, and the aromatic organic compound are brought into contact with each other through a mixing nozzle which comprises a substantially cylindrical tubular reactor and an annular gap which surrounds the tubular reactor. The aromatic organic compound flows through the tubular reactor, and the mixture of sulfuric acid and nitric acid flows through the annular gap, and they are mixed together upon emerging from the tubular reactor and the annular gap, wherein the ratio of the average rates of flow of the aromatic organic compound in the tubular reactor, and of the mixture of sulphuric acid and nitric acid in the annular gap ranges from 0.5:1 to 10:1.

Process for the production of dinitrotoluene

The invention relates to a process for the production of dinitrotoluene by the two-stage nitration of toluene. In the first stage of this process, toluene was reacted adiabatically with nitrating acid so that at least 90% of the toluene was reacted off and no more than 70% of the toluene formed dinitrotoluene. The resulting organic phase containing mononitrotoluene and the aqueous acid phase containing sulfuric acid were separated, and the aqueous acid phase containing sulfuric acid was concentrated by flash evaporation. The resulting concentrated sulfuric acid was recycled into the reaction in the first stage, and/or into the reaction in the second stage, and/or into the concentration in the second stage. In the second stage, the organic phase containing mononitrotoluene from the first stage was completely reacted isothermally with nitrating acid. The organic phase and the aqueous acid phase containing sulfuric acid were then separated, and the aqueous acid phase containing sulfuric acid was concentrated by vacuum evaporation. The resulting concentrated sulfuric acid was recycled into the reaction in the first stage and/or the second stage.

Process for the two-step production of dinitrotoluene

Growing community of inventors

Dormagen, Germany

Dietmar Wastian