Gas phase dehydration of glycerol catalyzed by gamma Al2O3 supported V2O5: a statistical approach for simultaneous optimization

Selective gas-phase dehydration of glycerol to acrolein over V2O5/g-Al2O3 catalysts was investigated. The catalysts with various V2O5 loading were facilely synthesized by an impregnation method. The prepared catalysts were characterized by several techniques such as scanning electron microscopy (SEM), temperature-programmed desorption of NH3 (TPD-NH3), temperature programmed reduction (H-2-TPR), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and X-ray diffraction (XRD). The effects of V2O5 loading (5-25 wt%), gas hourly space velocity (GHSV) of O-2/N-2 (120-540 h(-1)) and reaction temperature (250-320 degrees C) on yield of acrolein were studied by Box-Behnken design. The influence of independent factors and their quadratic interactions were examined by means of the analysis of variance (ANOVA). The present results indicate that temperature has a different effect on the conversion and selectivity of acrolein. The catalyst with 14.80 wt% of V2O5 loading, GHSV of 268.60 h(-1) and reaction temperature of 286.35 degrees C produced the maximum yield of acrolein (73.05%). The analysis revealed that the predicted results agree well with experimental data (12.5 wt% loading of V2O5 on gamma-Al2O3, GHSV of the carrier gas = 330 h(-1) and reaction temperature of 285 degrees C with 68.31% yield).