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

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which phosgene and amine are first evaporated and then superheated further to reaction temperature, and the superheated phosgene and amine are mixed and fed to a reactor in which the phosgene and the amine are converted to the isocyanate, wherein the residence time of the phosgene at temperatures greater than 300° C. is not more than 5 s, and/or the temperature of heat transfer surfaces in contact with phosgene is not more than 20 K above the phosgene temperature to be established. The invention further relates to an apparatus for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase.

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 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 an isocyanate, which involves contacting fluid streams of amine, phosgene and inert medium in at least one mixing device, such that an inert medium stream is metered at least between one amine stream and one phosgene stream within the mixing device, and then reacting an amine with phosgene in a reaction chamber to form an isocyanate. In this process the inert medium stream is metered such that a point of first contact of the amine and the phosgene occurs at a distance from a surface of the mixing device, and a turbulent flow is present in the reaction chamber.

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, optionally 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, and in which a reaction gas (1) which comprises isocyanate and hydrogen chloride leaving the reactor is cooled in a quench (3) by adding a liquid quench medium (5) to form a mixture of reaction gas and quench medium as the product stream (7). The quench medium (5) used is a mixture which comprises at least one solvent and isocyanate and which is withdrawn from the preparation process, any solid particles present in the quench medium (5) being removed before addition to the quench (3).

Abstract: A process for preparing isocyanates by phosgenation of the corresponding amines in a fluidized-bed reactor (R), wherein a gas stream (1) comprising the phosgene is used as fluidizing gas and keeps an inert solid in suspension and a liquid stream (2) comprising the amine is fed into the fluidized bed, with the amine vaporizing partially or completely and reacting with the phosgene to give a reaction gas mixture which comprises the corresponding isocyanate and is taken off from the fluidized-bed reactor (R) is proposed.

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, and in which a reaction gas which comprises isocyanate and hydrogen chloride and leaves the reactor is cooled in a quench space of a quench by adding a quench medium. The quench medium on addition to the quench space has a temperature above the condensation temperature or the desublimation temperature of the reaction gas.

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 at least one inert medium, the phosgene being passed into a reactor (21) through a first inlet and the amine through a second inlet of an ejector (1). The first inlet and the second inlet open into a mixing zone (17) in which the phosgene and the amine are mixed to give a reaction mixture. The mixing zone (17) is followed downstream by a diffuser (19) in which pressure and temperature of the reaction mixture composed of phosgene and amine are increased.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene, optionally in the presence of an inert medium, in which phosgene and amine are first mixed and converted to the isocyanate in a reactor, and in which a reaction gas which comprises isocyanate and hydrogen chloride leaving the reactor is cooled in a quench by adding a liquid quench medium to form a mixture of reaction gas and quench medium as the product stream. The walls of the quench are essentially completely wetted with a liquid.

Abstract: A process for preparing diisocyanates by gas-phase phosgenation starting out from a feed stream comprising the corresponding diamines and a phosgene-comprising feed stream, in which the feed streams are separately converted into the gas phase and preheated to the reaction temperature of the gas-phase phosgenation, wherein the waste heat from a plant for preparing chlorine by heterogeneously catalyzed oxidation of hydrogen chloride by the Deacon process is utilized for this purpose, is proposed.

Abstract: The present invention relates to a process for preparing isocyanates.

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 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: The invention relates to a process for preparing an isocyanate, which involves contacting fluid streams of amine, phosgene and inert medium in at least one mixing device, such that an inert medium stream is metered at least between one amine stream and one phosgene stream within the mixing device, and then reacting an amine with phosgene in a reaction chamber to form an isocyanate. In this process the inert medium stream is metered such that a point of first contact of the amine and the phosgene occurs at a distance from a surface of the mixing device, and a turbulent flow is present in the reaction chamber.

Abstract: A process for preparing isocyanates by phosgenation of the corresponding amines in a fluidized-bed reactor (R), wherein a gas stream (1) comprising the phosgene is used as fluidizing gas and keeps an inert solid in suspension and a liquid stream (2) comprising the amine is fed into the fluidized bed, with the amine vaporizing partially or completely and reacting with the phosgene to give a reaction gas mixture which comprises the corresponding isocyanate and is taken off from the fluidized-bed reactor (R) is proposed.

Abstract: The invention provides a process for preparing isocyanates by reacting amines with phosgene, wherein the amine or a mixture of amine and a solvent is mixed in the form of an aerosol with gaseous phosgene and the amine is subsequently reacted with phosgene.

Abstract: The present invention relates to a process for preparing diisocyanates from diamines and phosgene in the gas phase.