Temperature-programmed propane dehydrogenation over Pt–Sn/Al2O3 catalyst: Application in kinetic and catalyst deactivation studies

• Temperature-programmed reaction was applied to propane dehydrogenation (PHD).
• Kinetic parameters were obtained by nonlinear regression of conversion-time data.
• Activation energy of PDH (72 kJ/mol) is larger that of catalyst decay (21 kJ/mol).
• Simulated temperature-time profile for constant conversion shows upward curvature.
• Temperature-time trajectory would not be economically optimal in commercial PDH.

The kinetics of propane dehydrogenation and catalyst deactivation over Pt–Sn/Al2O3 catalyst was studied by temperature-programmed reaction. Catalytic runs were performed in a fixed-bed quartz micro-reactor both under constant (620 °C) and rising temperature. The reaction temperature was increased from 600 to 650 °C in such a way that the propane conversion remained the same with time over the deactivating catalyst. A model based on single reversible main reaction and first-order concentration-independent deactivation was used. The model was solved and optimized numerically to obtain the kinetic parameters of the main reaction and catalyst deactivation. Activation energies of 72 and 21 kJ/mol were obtained for the main reaction and catalyst deactivation, respectively. Within 150 h-on-stream, both temperature histories showed the same propylene yield, however the constant temperature operation gave this yield at lower propane consumption. The simulated temperature-time profiles for constant propane conversion showed an upward curvature (that is, accelerating type).