Patent application number | Description | Published |
20090043135 | PROCESS FOR THE SEPARATION BY DISTILLATION OF DINITROTOLUENE FROM PROCESS FOR THE SEPARATION BY DISTILLATION OF DINITROTOLUENE FROM PROCESS FOR THE SEPARATION BY DISTILLATION OF DINITROTOLUENE FROM PROCESS WASTEWATER FROM THE PREPARATION OF DINITROTOLUENE BY NITRATION OF TOLUENE BY MEANS OF NITRATING ACID - A process is proposed for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating toluene with nitrating acid, which comprises
| 02-12-2009 |
20100015012 | METHOD FOR PRODUCING AROMATIC AMINES OR ALIPHATIC AMINO ALCOHOLS - The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture. | 01-21-2010 |
20110251425 | PROCESS FOR PREPARING AROMATIC ISOCYANATES - The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, if appropriate in the presence of at least one inert medium, in which the amine and the phosgene are first mixed in a mixing chamber ( | 10-13-2011 |
20110295039 | PROCESS FOR PREPARING TOLUENEDIAMINE BY HYDROGENATION OF DINITROTOLUENE - The invention relates to a process for the continuous preparation of toluenediamine by liquid-phase hydrogenation of dinitrotoluene by means of hydrogen in the presence of a suspended, nickel-comprising catalyst in a reactor with a product isolation unit downstream of the reactor to give a product output from the reactor comprising a liquid phase comprising toluenediamine and dinitrotoluene, in which the nickel-comprising catalyst is suspended, wherein the concentration of dinitrotoluene in the liquid phase of the product output from the reactor in the region between the reactor and the downstream product isolation unit is set to a value in the range from 1 to 200 ppm by weight, based on the total weight of the liquid phase of the product output from the reactor. | 12-01-2011 |
20120101299 | PROCESS FOR THE PRODUCTION OF ISOCYANATES, PREFERABLY DIISOCYANATES AND POLYISOCYANATES WITH SOLVENT RECIRCULATION - The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and re-circulation of at least a portion of the solvent streams. | 04-26-2012 |
20120108844 | METHOD OF MEASURING ENTRY OF WATER INTO PHOSGENE-CONDUCTING PLANTS - The invention relates to a method of measuring entry of water and resulting corrosion in plants for producing isocyanates by reacting phosgene with one or more primary amines in a solvent. The invention further relates to an apparatus for producing such isocyanates, in the work-up section of which probes for monitoring corrosion are arranged in defined places. | 05-03-2012 |
20120289746 | PROCESS FOR WORKING UP AN ISOCYANATE-COMPRISING STREAM - The invention relates to a process for working up a stream ( | 11-15-2012 |
20130211141 | MONITORING OF THE STOICHIOMETRIC RATIO IN THE REACTION OF NITROAROMATICS WITH HYDROGEN - The present invention relates to a continuous process for preparing at least one aromatic amine by hydrogenation of at least one nitroaromatic by means of hydrogen, where a liquid phase comprising at least the aromatic amine and a gas phase comprising at least hydrogen are present, in the presence of a catalyst suspended in the liquid phase at a temperature of from 50 to 250° C. and a pressure of from 5 to 50 bar, wherein the pressure in the reactor is kept essentially constant by continuous adaptation of the amount of hydrogen fed to the reactor, the total amount of hydrogen fed to the reactor is monitored and the introduction of the at least one nitroaromatic is interrupted if the hydrogen uptake in the reactor is not at least 50 mol % of the amount of hydrogen required for stoichiometric reaction of the at least one nitroaromatic to form the at least one aromatic amine. | 08-15-2013 |