Abstract:
The invention relates to a process for the production of phosgene comprising a gas phase reaction of carbon monoxide and chlorine in the presence of a carbon catalyst in a multi-tubular reactor, wherein the carbon catalyst comprises an amount of mesopores having a pore diameter in the range of from 2 to 50 nm of at least 0.45 ml/g of the total pore volume and the use of a carbon catalyst comprising an amount of mesopores having a pore diameter in the range of from 2 to 50 nm of at least 0.45 ml/g of the total pore volume, for the production of phosgene and a reaction mixture for preparing phosgene, the mixture comprising a catalyst for preparing phosgene comprising a porous material comprising carbon, micropores and mesopores, wherein said micropores have a pore diameter of less than 2 nm and wherein said mesopores have a pore diameter in the range of from 2 to 50 nm, wherein the volume of the mesopores of the porous material is of at least 0.45 ml/g, and a gas stream G comprising carbon monoxide (CO) and chlorine (Cl2).
Abstract:
Chemical reactor comprising an educt space with inlet means for feeding at least one educt stream into said space: a product space with outlet means for removing at least one product stream from said space: a plurality of parallel tubes extending from the educt space to the product space in an axial direction, forming a tube bundle, wherein the tubes comprise at least one heterogeneous catalyst: a cooling liquid space surrounding at least a section of the tube bundle, wherein said space has an inlet and an outlet spaced from the inlet at least in the axial direction, and wherein the cooling liquid space defines a cooling liquid flow path between inlet and outlet: n cooling liquid temperature measuring devices MD(i), i=1 . . . n, n>2, inside the cooling liquid space, wherein MD(i+1), is located upstream of MD(i) in the cooling liquid flow path.
Abstract:
The invention relates to a process for preparing isocyanates by reacting primary amines with phosgene in a solvent, where the solvent comprises a dialkyl carbonate.
Abstract:
The invention relates to a process for preparing isocyanates by reacting primary amines with phosgene in a solvent, where the solvent comprises a dialkyl carbonate.
Abstract:
The invention relates to a method of regulating the viscosity of a mixture (125; 210) comprising at least two components having different viscosities, which comprises the steps:(a) determination of the viscosity (132; 222) of the mixture (125; 210) by means of ultrasound measurements,(b) standardization of the viscosity determined (132; 222) to standard conditions,(c) comparison of the standardized viscosity (14) with a prescribed intended value (134; 224),(d) adjustment of the viscosity of the mixture (125; 210) by increasing or decreasing the proportion of at least one component of the mixture,where the ultrasound measurements in step (a) are carried out at or in a line conveying the mixture or in a vessel.
Abstract:
The invention relates to a process for producing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, comprising: (a) mixing an amine comprising feed stream, a phosgene comprising feed stream and optionally an inert solvent; (b) reacting the amine with phosgene in a first reaction section to obtain an intermediate reaction mixture comprising isocyanate, carbamoyl chlorides, amine hydrochlorides and unreacted phosgene; (c) cleaving the carbamoyl chlorides and remove phosgene from the intermediate reaction mixture in a second reaction section to obtain an isocyanate comprising crude product, (d) optionally working-up the crude product; wherein reacting (b) is carried out such that the intermediate reaction mixture comprises 1.7 to 5 mol-% solid amine hydrochlorides based on the molar amount of amine fed into the process.
Abstract:
The invention relates to a process for producing phosgene by gas phase reaction of carbon monoxide and chlorine in the presence of a catalyst in a reactor that comprises a plurality of contact tubes arranged parallel to one another, which contact tubes are filled with the catalyst and around which at least one fluid heat transfer medium flows, a feed stream of a mixture of a chlorine input stream and a carbon monoxide input stream being conducted into the contact tubes and reacted to form a phosgene-containing product gas mixture, characterised in that the product gas mixture is discharged from the contact tubes at an outlet end of the contact tubes. The method according to the invention is characterised in that the gas phase reaction is carried out in the reactor such that the position of the highest temperature in a contact tube (hot spot) moves along the longitudinal axis of the contact tube at a predetermined rate of migration, the hot spot having a rate of migration in the longitudinal direction of the contact tubes which is in the range of 1 to 50 mm per day. The invention also relates to a reactor for carrying out the process.
Abstract:
The present invention relates to a process for hydrogenating a mixture (G1) in the presence of a catalyst, where the mixture (G1) comprises at least one colorless amine and at least one color-imparting component. As a result of the hydrogenation step, the at least one color-imparting component is firstly partially, preferably fully, hydrogenated, while the colorless amine, in particular aniline, is not hydrogenated or hydrogenated to only a very small extent. The color-imparting components which cause the discoloration of the amine which is itself in principle colorless are thus removed by hydrogenation, as a result of which purification of the colorless amine or the mixture (G1) is achieved.
Abstract:
The present invention relates to a process for preparing at least one polyisocyanate R(—NCO)x, the process comprising preparing a mixture R1 comprising at least one polyamine R(—NH2)x, with x=2 or more, in a first reaction zone Z1; passing at least a portion P1 of the mixture R1, P1 comprising R(—NH2)x, into a storing device D1 and storing P1 in D1 for a period of time Δt1; removing, after storing for Δt1, at least a portion P2 of P1, P2 comprising R(—NH2)x, from D1; passing P2 into a reaction zone Z2; and reacting, in Z2, R(—NH2)x comprised in P2 with phosgene, obtaining a mixture R2 comprising the at least one polyisocyanate R(—NCO)x; wherein Δt1 is in the range of from 1 minute to 7 d.