Deactivation kinetics of platinum-based catalysts in dehydrogenation of higher alkanes

The deactivation of promoted Pt-Al2O3 catalyst in dehydrogenation of C10–C14 normal paraffins to the corresponding mono-olefins was studied. Two models based on reversible and irreversible main reaction and nth order, concentration-independent deactivation kinetic was used. The kinetic parameters were obtained by utilizing non-linear estimation functions of industrial plant time–temperature trajectory data. The reversible reaction model showed a better fit to the plant data. The results were also checked through integral analysis of experimental data. The results of both approaches were consistent and showed a second-order decay law. The activation energies of the dehydrogenation and catalyst decay were found to be EA = 90 kJ/mol and Ed = 140 kJ/mol, respectively. The larger activation energy for catalyst deactivation compared to that of main reaction implies that catalyst decay is much more temperature sensitive than main reaction.