Process for preparing aromatic amines
AssigneeBASF SE
InventorsStefanie Haase, Dusko Kadijevic, Anne-Kathrin Merten, Michael Zoellinger, Andreas Raichle, Alexander Schocker, Sandra Mühlbeyer, Olaf Wiedenhoff, Joana Coelho Tsou
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Abstract
A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.
Claims30
A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture or a measurement of the absorption of IR- and/or VIS-radiation through the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture, with the result of the determination of the concentration of nitro and nitroso compounds being used for process control or regulation of the hydrogenation, wherein samples are fed on-line via a bypass to the chromatograph and wherein the bypass is equipped with an automated liquid metering valve for sampling, optionally with upstream particle filter.
A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture or a measurement of the absorption of IR- and/or VIS-radiation through the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture, with the result of the determination of the concentration of nitro and nitroso compounds being used for process control or regulation of the hydrogenation, wherein to determine the concentration of the nitro and nitroso compounds, a gas chromatogram of the reaction mixture is produced and evaluated, and wherein the introduction of the reaction mixture into the gas chromatograph is carried out by means of an automated liquid metering valve heated to at least 80° C.
A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture or a measurement of the absorption of IR- and/or VIS-radiation through the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture, with the result of the determination of the concentration of nitro and nitroso compounds being used for process control or regulation of the hydrogenation, wherein sampling for the concentration determination is carried out in a bypass for the liquid product output downstream of a product isolation unit or in a bypass for the liquid product output between reactor and product isolation unit and wherein the bypass is equipped with an automated liquid metering valve for sampling, optionally with upstream particle filter.
Dependencies are inferred from the claim text.