Patent ID: 8907144

Claim:
A continuous adiabatic process for the production of mononitrotoluene, comprising: (a) feeding into a reactor toluene and a mixed acid, the mixed acid comprising nitric acid, sulfuric acid and water, the molar ratio of the toluene to the nitric acid being greater than 1, the toluene and the mixed acid comprising a two-phase mixture; (b) passing the two-phase mixture through the reactor to react the toluene with the mixed acid, producing mononitrotoluene and a spent acid phase; (c) selecting the values of the reaction parameters such that the nitric acid is not fully consumed and the spent acid phase contains at least 0.003 wt % nitric acid and such that the produced mononitrotoluene comprises less than 0.5 wt % dinitrotoluene and less than 1 wt % of cresols plus benzoic acids; (d) separating an organic phase comprising the mononitrotoluene from the spent acid phase; (e) concentrating the spent acid phase to produce a concentrated sulfuric acid; and (f) recycling the concentrated sulfuric acid for use in step (a).