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

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a process for recovering acids from product streams of organic syntheses, which comprises the steps a) neutralization of the acid with a base, b) removal of the base by means of adsorption, c) recovery of the acid.

Abstract: A process is proposed for preparing isocyanates by phosgenating the corresponding amines in the gas phase, which comprises dividing a phosgene-containing reaction mixture from the gas phase synthesis of carbon monoxide and chlorine to phosgene, which is run with a stoichiometric carbon monoxide excess over chlorine, by means of a thermal separating process and/or of a membrane separating process into two streams, specifically into a first, low-carbon monoxide stream comprising not more than 1% by weight of carbon monoxide, based on the total weight of the first, low-carbon monoxide stream, and into a second, carbon monoxide-rich stream comprising more than 10% by weight of carbon monoxide, based on the total weight of the second, carbon monoxide-rich stream, and using the first, low-carbon monoxide stream as a reactant stream in the phosgenation of amines to isocyanates in the gas phase.

Abstract: 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.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, in the presence or absence of an inert medium, which comprises the following steps: (a) vaporization of the amine in a vaporizer, (b) superheating of the amine, (c) mixing of the gaseous amine with the phosgene and introduction into a reaction zone, (d) reaction of amine and phosgene to give isocyanate in the reaction zone, with a reaction mixture comprising isocyanate and hydrogen chloride being formed, (e) cooling of the reaction mixture comprising isocyanate and hydrogen chloride, wherein the vaporizer comprises a vessel in which tubes through which a heating medium flows are comprised, where number and diameter of the tubes are designed so that the tubes have a specific heat transfer area based on the volume through which the amine flows of at least 300 m2/m3.

Abstract: The present invention relates to a process for preparing isocyanates and an apparatus suitable for this purpose, and also its use.