Bayer Aktiengesellschaft

Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Sven Michael Hansen

Peter Fischer

Claus-Peter Reisinger

Hans-Peter Wirges

Michael Traving

Joachim Helbig

Konrad Triebeneck

Jürgen Dreher

Bernd Schwethelm

Hauke Murken

Ralf Schneider

Rolf Schiefer

Chef knife

Isocyanates are produced in the gas phase and by-products such as ammonium halides are selectively separated from the gas phase by desublimation.

Separation of ammonium chloride from the gas phase of an isocyanate production process

A process for the preparation of an aromatic carbonate is disclosed. The process entails reacting an aromatic hydroxy compound of the formula R&#x2014;(O&#x2014;H), with carbon monoxide and oxygen, optionally in a solvent and in the presence of catalyst components, characterized in that after an initial partial charge of R&#x2014;(O&#x2014;H)to the reaction mixture, the balance thereof is subsequently metered into the reaction mixture at least once in the course of the reaction.

Process for the preparation of diaryl carbonates

The preparation of quaternary salt phenolate solutions is disclosed. The preparation entails mixing an aqueous hydroxide-containing solution with an organic phase that contains phenol and quaternary salt, distilling off the water and precipitating and filtering off the resulting salt.

Process for the preparation of quaternary salt phenolate solutions

The invention relates to a process for the removal of deposits formed in a reaction apparatus by the precipitation of solids from a liquid reaction mixture, which process is characterized in that particles of a material that is inert under the reaction conditions are introduced into the reaction apparatus, which particles, by suitable mechanical circulation of the reaction mixture, are so moved through the reactor that, during the reaction, by striking the walls or other built-in elements, they abrasively remove precipitates adhered thereto.

Method for removing deposits from chemical reactors

A process for the separation a substantially adduct-free diaryl carbonate from reaction solution is disclosed. The process entails obtaining a solution that contains diaryl carbonate, catalyst system components and an aromatic solvent, lowering the temperature of the solution, optionally in the presence of a nucleating agent, to produce a crystallization product, and washing the crystallization product with an anhydrous wash solution to remove catalyst residues and impurities.

Separation of impurities and/or valuable substances from solutions containing diaryl carbonate by solution crystallization

A process for producing diaryl carbonate is disclosed. The process entails forming a reaction mixture wherein reacting are an aromatic hydroxy compound corresponding to the formulaR&#x2014;O&#x2014;H&#x2003;&#x2003;(II),wherein R denotes a C-aromatic hydrocarbon radical, with CO and Oin the presence of a catalyst system. The catalyst system contains components a) a Group VIII B metal compound, b) at least one second metal compound, c) a bromide compound, and d) a base. The process entails introduction of one or more of components a) to d) to the reaction mixture in more than one increment in the course of the reaction.

Process for producing diaryl carbonates

Process for separating reaction mixtures and recycling quaternary salts and bases

A process for the separation and recycling of catalyst components from a chemical reaction mixture is disclosed. The process entails at least one extraction step.

Process for the separation of reaction mixtures and the recirculation of quaternary salts

A process for the preparation of a solution of a quaternary cation and an anion from a deprotonated hydroxy aromatic in an organic solvent by means of a reactive extraction of a quaternary salt in the presence of an aqueous hydroxide solution, a hydroxy aromatic and an organic solvent is disclosed. Also disclosed is a process for the recycling of a quaternary salt phenolate solution from a reaction mixture.

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Leverkusen, Germany

Sven Michael Hansen