| 摘要 |
<p>The method comprises contacting nitrated crude products with a washing medium to produce an emulsion by a mixing unit, and subsequently feeding the produced emulsion in a tubular reactor so that, during a passage of the emulsion, impurities obtained in nitrated crude products are removed through the tubular reactor and are transferred into the washing medium. The mixing unit comprises agitated vessels, a jet mixer or a centrifugal pump. The jet mixer generates a central propulsion jet, and a medium in the form of an annular beam surrounding the propulsion jet. The method comprises contacting nitrated crude products with a washing medium to produce an emulsion by a mixing unit, and subsequently feeding the produced emulsion in a tubular reactor so that, during a passage of the emulsion, impurities obtained in nitrated crude products are removed through the tubular reactor and are transferred into the washing medium. The mixing unit comprises agitated vessels, a jet mixer or a centrifugal pump. The jet mixer generates a central propulsion jet, and a medium in the form of an annular beam surrounding the propulsion jet. A ratio of speed between the central propulsion jet and the medium is 1:1-10:1. The mixing unit is integrated into the tubular reactor, and is a component of the tubular reactor. The tubular reactor is equipped with mixing elements for entering a mixing energy. The mixing elements are formed as static mixer or flow divider. The mixing energy of the mixing elements is 20-200 J/l and/or a pressure drop of per mixing element is 0.3-0.8 bar. A delay time in the tubular reactor is 1-30 seconds. A mass ratio between the nitrated crude products and the washing medium is 10:1-1:2, and/or a phase ratio between the nitrated crude products and the washing medium is 5:1-1:1. The washing medium is present in water state under process conditions at a temperature of 25[deg] C and an atmospheric pressure. A base having a concentration of 0.02-0.2 mol/l is added to the washing medium. The nitrated crude products: are present in liquid state under process conditions at the temperature of 25[deg] C and the atmospheric pressure; derived from a nitration of benzene, toluene and xylene, and/or optionally halogenated with mono-, di- and tri-nitroaromatics. The step of feeding the resulting emulsion in the tubular reactor comprises connecting a separation of the nitrated products liberated by the impurities of the washing medium in a sheath device. A mixture withdrawing from the tubular reactor is transferred from the cleaned nitrided products and the washing medium before separation of the nitrided products liberated from the impurities of the washing medium into the agitated vessels. The washing medium is recycled after separation of the nitrided products. Independent claims are included for: (1) an apparatus for removing impurities from nitrated crude products obtained during nitration of aromatic compounds; and (2) a production plant for nitration of aromatic compounds with subsequent purification.</p> |
