Industrial & Engineering Chemistry Research, Vol.53, No.40, 15317-15332, 2014
Kinetic Modeling of Propane Oxidative Dehydrogenation over VOx/gamma-Al2O3 Catalysts in the Chemical Reactor Engineering Center Riser Reactor Simulator
This study reprts kinetic modeling of propane oxidative dehydrogenation (ODH) employing a new VOx/gamma-Al2O3 catalyst especially desigened for propane ODH with controlled acidity This catalyst is prepared with different vanadium loadings (5-10 wt %). Kinetic experiments are carres out under and oxygen-free atmosphere in the Chemical Reactor Engineering Center fluidized bed riser simulator at 475-550 degrees C and atmospheric pressure. Sucesssive-injection propane ODH experiment without catalyst regenration) over partially reduced catalysts show good propane conversions (11.73%-15.11%) and promising propylene selectivity (67.65-85.89%). Regarding propylene selectivity, it increases while that for CO2 decreases as the catalyst degree of reductio augements with the consecutive propane injectins. This suggests that a controlled degree of catayst reduction is needed for hig propyers selectivey Under such oxygen tree conditions the lattice oxygen of the catalyst is consumed via the ODH reaction. On reaction. On the basis of the data botained, a kinetic model is propsed. In this model. reaction rates are related to the degree of catalyst reduction using an expoential deasy function. The Kinetic and decay model parametes are estimate using nonlinear regression analysis. Activatin energies and Arrhenius pre-exponential constants are calculated with their respective confidence inervals. The propsed parrelle-series kinetic model staisfactiorly predicts the ODH reaction of propane under the selected reaction conditions.