Kinetic modeling of simultaneous dehydrogenation of propane and isobutane on Pt-Sn-K/Al2O3 catalyst

• Reactor study of the simultaneous dehydrogenation of propane, isobutene mixture.
• Kinetic modeling of simultaneous dehydrogenation of C3–iC4 mixture on Pt-Sn-K/Al2O3.
• Introducing new reaction rate equations based on Langmuir-Hinshelwood approach.
• Model screening among several rival models.
• Sensitivity analysis of kinetic parameters, and simplifying of best selected model.

The kinetics of simultaneous dehydrogenation of propane and isobutane over a commercial Pt-Sn-K/Al2O3 catalyst is reported. The experiments were carried out in a laboratory-scale plug flow reactor over the temperature range of 560–600 °C at atmospheric pressure. Several Langmuir-Hinshelwood mechanisms for C3 and iC4 were tested. Models were derived with the assumption of propane, isobutane and hydrogen adsorption on the same type of active site. A simple deactivation model was used for fitting the kinetic data, then the best fit for these reactions was found with the rate determining step (RDS) of surface reaction for propane and adsorption on the catalyst surface for isobutane. The results showed a good agreement between experimental and calculated data for these simultaneous reactions.