| 摘要 |
A process for producing dinitrotoluene is provided to allow the use of simple plant equipment, to realize high selectivity to dinitrotoluene and high toluene conversion, and to permit highly selective use of nitric acid introduced directly to a reaction step. A process for producing dinitrotoluene comprises the steps of: (a) reacting a toluene-containing organic phase with a nitrated acid-containing aqueous phase to form a reaction mixture containing mononitrotoluene; (b) separating the reaction mixture containing mononitrotoluene into a mononitrotoluene-containing organic phase and a sulfuric acid-containing aqueous phase; (c) reacting the mononitrotoluene-containing organic phase with nitrated acid to form a reaction mixture containing dinitrotoluene; and (d) separating the reaction mixture containing dinitrotoluene into a dinitrotoluene-containing organic phase and a sulfuric acid-containing aqueous phase. In step (a), the weight ratio of the aqueous phase:organic phase is greater than 2:1. In step (b), the weight ratio of the aqueous phase:organic phase is greater than 1.5:1. In each of step (a) and step (c), the organic phase is dispersed in the aqueous phase. Additionally, less than 2.06 mole of nitric acid is used per mol of toluene.
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