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 isocyanates, comprising (a) the reaction of at least one amine with phosgene in the gas phase in a reaction zone and (b) the subsequent cooling of the reaction gases in a cooling zone by means of indirect cooling, the cooling medium which absorbs the heat of the reaction gases being conducted in countercurrent to the product stream at least in the region of the highest temperature in the cooling zone.

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: 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, 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: 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: 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: 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, 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: The invention relates to a process for preparing isocyanates, comprising (a) the reaction of at least one amine with phosgene in the gas phase in a reaction zone and (b) the subsequent cooling of the reaction gases in a cooling zone by means of indirect cooling, the cooling medium which absorbs the heat of the reaction gases being conducted in countercurrent to the product stream at least in the region of the highest temperature in the cooling zone.

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.