Kinetic model discrimination of toluene hydrogenation over noble metal supported catalyst

The hydrogenation of toluene was studied using an integral fixed bed reactor with a Pt/γ-Al2O3 commercial catalyst over a wide range of experimental conditions: temperature = 100-250°C, H 2 inlet pressure = 0.3-1.9 bar, toluene inlet pressure = 0.04-0.15 bar, and space time = 2-10·10-2 gcat h g tol -1. Hydrocarbon molecules blocked the active sites at elevated temperature and toluene partial pressures, as a consequence three reaction-controlled regimes can be found: (i) kinetic, (ii) surface coverage and (iii) thermodynamic. The experimental data were fitted to 23 kinetic models proposed in the literature (empirical and mechanistical), estimating their parameters, while the model discrimination was based on statistical F-test and mechanistical aspects. From the best of our knowledge, a simplified kinetic model was proposed, introducing the thermodynamical equilibrium constant. Finally, that kinetic model was used to develop a simulation.