Résumé

Although nitrations of arom. compds. are of considerable importance, it is still difficult to predict effective rates of nitration in the heterogeneous two-liq.-phase system used in industry. For the nitrations of several arenes such as toluene and benzene, the nitration reactions occur in the aq. acid phase or at the interface between liq. phases. The arom. reactant must hence be transferred from the org. to the inorg. phase. Thus the design and scale-up of industrial nitrators is strongly influenced by the simultaneous mass-transfer and chem. reaction. To get proper design parameters, it is essential to know the limiting step. Based on published data on the reaction rate as a function of the acidity of the inorg. phase in the temp. domain up to 40 Deg, an overall kinetic model for the nitration of benzene is presented, which allows the prediction of chem. reaction rates under industrial conditions and temps. up to 140 Deg. The kinetic model was exptl. verified in a large domain of reaction parameters using a stationary continuous stirred tank reactor as nitrator. Besides the kinetics of heterogeneous nitration, the solubilities of the reactants in each phase were studied. [on SciFinder (R)]

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