Phenomenologically based kinetics of ODH of ethane to ethylene using lattice oxygen of VOx/Al2O3-ZrO2 catalyst

- Kinetics of ODH of ethane to ethylene with lattice oxygen of VOx/Al2O3-ZrO2.
- Catalyst lattice oxygen favors high ethylene selectivity up to 82%.
- The depletion of catalyst lattice oxygen is modeled using TPR data.
- Series-parallel reaction network is developed using CREC Riser Simulator data.
- A Langmuir-Hinshelwood model satisfactorily predicts the experimental data.

This study addresses the kinetic modeling of ethane oxidative dehydrogenation (ODH) over a 10% wt VOx 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.

Schematic representation of the Langmuir-Hinshelwood mechanism for ODH of ethane to ethylene using lattice oxygen of VOx/Al2O3-ZrO2 catalyst.132