Covestro Deutschland Ag

Jiangsu Synecoun Medical Technology Co., Ltd

Bastian Mahr

Friedhelm Steffens

Amgad Salah Moussa

Bernd Pennemann

Michael Merkel

Peter Lehner

Ekkehard Barth

A method for producing isocyanates by reacting primary amines with phosgene in a stoichiometric excess in the gas phase, wherein the excess phosgene is subsequently recovered and recirculated back into the reaction. particular a method for the feedback-controlled recirculation of the recovered phosgene, particularly when the phosgene stream that should be recovered is distributed between multiple gas-phase reactors operated in parallel.

Method for producing isocyanates

The present invention relates to a process for separating an isocyanate prepared by reaction of a primary amine with an excess of phosgene in the gas phase from the gaseous crude product obtained in the reaction, wherein

Process for separating an isocyanate prepared by phosgenation of a primary amine in the gas phase from the gaseous crude product of the phosgenation

In a process for producing a spinnable silica sol material, a viscosity value Vis stipulated which the spinnable silica sol material should have after ripening. A viscosity value Vcorresponding to Vwhich the silica sol material has before ripening is ascertained. An aqueous acid solution and a hydrolysable silicon compound are combined. The combined mixture is evaporated to give a single-phase solution while measuring the viscosity of the mixture and the evaporation process is terminated upon reaching the viscosity value V. The single-phase solution thus obtained is then ripened to give a silica sol material with the viscosity value V. The process exhibits reduced waste and more exact reproducibility of the spinning sol properties during the synthesis and an increased space-time yield in the production of biologically degradable and/or resorbable fibers and nonwoven fabrics.

Method for producing a spinnable silica sol material

The invention relates to an industrial-scale method for the vapor-phase hydrogenation of dinitrotoluene (DNT). According to said method, a stream containing DNT is sprayed into a carrier-gas stream containing hydrogen, optionally in the presence of an atomizing gas, unevaporated liquid droplets are extracted from the substantially gaseous stream that is obtained and the resultant gas stream is catalytically hydrogenated to form diaminotoluene.

Method for producing diaminotoluene

The present invention relates to a process for the purification of aniline which originates from gas phase hydrogenations. In this process, only a minimum proportion of the aniline has to be evaporated and condensed again. The process is highly efficient in removing compounds which have phenolic hydroxyl groups and results in minimal losses of aniline. This process also reduces the unwanted coupling mechanisms in the division of the overall crude product in the fraction condensation into individual substreams and the subsequent workup of these.

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Bergisch Gladbach, Germany

Bastian Mahr