Mononitrochlorobenzene (MNCB)

The mixture of Mononitrochlorobenzene isomers, produced from Chlorobenzene with Nitric Acid in the presence of Sulfuric Acid by the adiabatic process, or from Chlorobenzene and NCB mixed acid by the conventional nitration process, serves for obtaining the separate isomers. These are mainly used as raw materials in the dyeing chemistry and the agricultural chemistry. Meissner's adiabatically working MNCB plants are characterized by application of tube reactors which minimize the formation of by-products by optimum intermixing of the reactants, practically excluding any back mixing in the tube reactor. Due to the adiabatic process, the reconcentration of the Sulfuric Acid obtained after separation of the Mononitrochlorobenzene is performed directly in the plant. The raw Mononitrochlorobenzene is automatically fed to the washing section consisting of Meissner compact washing units performing the washing as well as the separation of the product from the respective washing medium. The purified Mononitrochlorobenzene contains Chlorobenzene, which is separated by means of steam from the Mononitrochlorobenzene in the subsequent stripping unit, and which is returned into the process. Meissner MNCB plants using the conventional nitration process are characterized by application of circulation reactors which have been developed especially for nitration purposes, and which ensure a high degree of security due to their large cooling areas for a small reactor volume. The circulation pumps used in the reactors accomplish an optimum conversion of the reactants providing a constantly high quality of MNCB. For safety reasons the separation of the mixture of MNCB isomers from the spent acid is carried out in dynamic separators, which are characterized by a short separation time (within the range of seconds) and a very small volume. The mixture of MNCB isomers is automatically fed to the washing section consisting of compact Meissner washing units which perform the washing as well as the separation of the product from the washing medium. Meissner as main contractor offers, along with the MNCB plant, also the spent acid regeneration plant for recovery of concentrated Sulfuric Acid and Nitric Acid.