Effect of kinetic models on hot spot temperature prediction for phthalic anhydride production in a multitubular packed bed reactor

Although there are several kinetic models for the production of phthalic anhydride from the partial oxidation of o-xylene, only few studies have compared the effect of the kinetic model on the prediction of the hot-spot temperature. In this work, the predicted temperature profile for the partial oxidation of o-xylene to phthalic anhydride in a multitubular packed bed reactor was obtained for different kinetic mechanisms using one-dimensional pseudo-homogeneous and heterogeneous models. The predicted temperature profile using the one-dimensional heterogeneous model with the kinetic model of Calderbank et al. but with the adjusted kinetic and transport parameters proposed by Anastasov presented a good correlation with regard to experimental data. Nevertheless, in the hot-spot zone deviations, up to 30K were presented. In conclusion, the temperature performance in the production of phthalic anhydride is suitably predicted by the one-dimensional heterogeneous model and the Calderbanket al.'s kinetic model. Though, prediction using bidimensional models should be done to establish the best correlation with experimental data.