Phenomenologically based kinetics of ODH of ethane to ethylene using lattice oxygen of VO_x/Al₂O₃–ZrO₂ catalyst

This study addresses the kinetic modeling of ethane oxidative dehydrogenation (ODH) over a 10% wt VO_x catalyst supported on Al₂O₃–ZrO₂ (1:1) in the CREC Riser Simulator Reactor. The catalyst was synthesized using impregnation by a soaking method. Following this, the catalyst was characterized using BET, XRF, TPR, NH₃-TPD and Raman Spectroscopy. The ODH catalyst was studied in a fluidized CREC Riser Simulator at a temperature range of 525–600 °C and with 20–50 s contact time. Good ethylene selectivity of up to 82% at 8.5% ethane conversion was attained. A kinetics model was established using a Langmuir–Hinshelwood rate equation. Catalyst activity (availability of lattice oxygen) was first modeled using TPR results. This model was then incorporated with the developed L–H model for the series-parallel reaction network. Nonlinear regression was employed to estimate kinetic parameters and activation energies with their respective confidence intervals. The proposed kinetics for ODH, satisfactorily predicted ethane conversion and selectivity at the selected operating conditions.