Thermo-kinetic and diffusion studies of glycerol dehydration to acrolein using HSiW-Γ-Al2O3 supported ZrO2 solid acid catalyst

Abstract

The thermo-kinetic study of gas-phase glycerol dehydration reaction using a supported γ-Al2O3 nanoparticle based solid catalyst (SiW20-Al/Zr10) has been investigated. The kinetic model was established based on the reaction mechanism, taking into account two parallel reactions of glycerol degradation into acrolein or acetol. Reaction rate constants and activation energies for all the products in the glycerol dehydration reaction were determined at various reaction temperatures (280–340 °C). The first-order kinetic model and the experimental data fitted-well. Also, based on thermodynamic analysis the values of ΔH‡, ΔS‡, and ΔG‡ for all the endothermic reactions were determined by Eyring equation. Finally, the absence of internal and external diffusions were confirmed by Weisz-Prate Criterion (CWP <1) and Mear's Criterion (CM < 0.15), respectively for pellet diameters less than dP < 5 μm. The results from this study are useful for future reactor modeling and simulation work.