Basf Se Corporation

Basf Aktiengesellschaft

Carsten Knösche

Torsten Mattke

Eckhard Stroefer

Gerhard Olbert

Markus Weber

Heiner Schelling

Andreas Daiss

Joachim Pfeffinger

Bernd Sachweh

Andreas Wölfert

Eckhard Ströfer

Michael Schönherr

Veronika Wloka

Martin Karches

Bernd Rumpf

Hermann Ascherl

Nils Bottke

Christian Müller

Heinrich-Josef Blankertz

Manfred Heilig

Bernhard Geissler

Daniel Breuninger

Vanessa Simone Lehr

Dieter Stützer

Christian Benz

Matthias Klötzer

Markus LINSENBÜHLER

Patric Müller

The present invention comprises a process for purifying isocyanate-comprising residues.

Method for purifying residues containing isocyanates

The present invention relates to gas phase phosgenation of amines for preparation of isocyanates. In the present invention, phosgene is prepared by reacting chlorine with an excess of carbon monoxide in a gas phase. The obtained phosgene-containing reaction mixture is divided into two streams by a thermal and/or a membrane separating process. The first stream is a low-carbon monoxide stream of no more than 1% by weight of carbon monoxide, based on a total weight of the first stream. The second stream is a carbon monoxide-rich stream of more than 10% by weight of carbon monoxide, based on a total weight of the second stream. The first stream is used as the phosgene-containing reactant stream in the gas phase phosgenation of amines to prepare isocyanates. The second stream can be recycled into the phosgene synthesis.

Process for preparing isocyanates

The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, if appropriate in the presence of an inert medium, in which the amine and the phosgene are first mixed and converted to the isocyanate in a reactor, by cooling a reaction gas which comprises isocyanate and hydrogen chloride and leaves the reactor in a quench by adding a liquid quench medium to obtain a mixture of reaction gas and quench medium. The amount of quench medium added is such that the temperature of the mixture of reaction gas and quench medium which is established in the quench is above the dew point of the gas present in the quench.

The invention relates to a process for recovering acids from product streams of organic syntheses, which comprises the steps

Method for the recovery of mineral acids from saline solutions

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Niederkirchen, Germany

Carsten Knösche