Heat effects due to dilution during aromatic nitrations by mixed acid in batch conditions

Abstract

Although the heat produced by aromatic nitration is relatively large in comparison to the heat produced by dilution, knowledge of the rate of heat generation due to dilution of the mixed acid is important for predicting the dynamic behaviour of discontinuous nitration processes. In this paper a mathematical model, its implementation and experimental validation of the heat effects due to dilution are described and discussed.

Aromatic nitrations by mixed acid. Fast liquid-liquid reaction regime

“…[22]). Here, the heat of dilution, which plays an important role in the total heat generated during nitration, has been evaluated using a model developed in previous work [23]. Furthermore, the selectivity and yields were directly determined from concentration measurements by gas chromatography [24] and then compared with the reaction rate determined by calorimetric measurements [25].…”

Mathematical modelling and numerical simulation of aromatic nitrations by mixed acid in discontinuous reactors

“…The precision of this calorimetrie method depends on the correct representation of all the secondary heat effects like heat losses, stirring power supply, heat taken up by reactor wall and dilution heat see Hernández et al (1993). In this particular case, the heat of dilution, which cannot be neglected as part of the total heat generated during the nitration, was evaluated using a model developed in previous work, see Zaldivar et al (1992b). The experiments in the reaction calorimeter were carried out in such a way so as to assure the overall conversion rate is always controlled by chemical reaction.…”