Physiochemical characterization and support interaction of alumina‐supported heteropolyacid catalyst for biodiesel production

Abstract

12-Tungstophosphoric acid (TPA)-supported γ-Al 2 O 3 catalysts were synthesized with varying TPA loadings. Catalysts characteristics were determined using Brunauer-Emmett-Teller surface area analysis, thermogravimetric analyses, X-ray diffraction, Raman, pyridine-adsorbed Fourier-transform infrared spectroscopy, and 13 C hpdec (high-power 1 H decoupling) nuclear magnetic resonance, whereas surface morphology was studied using scanning electron microscope and transmission electron microscopy analyses. Surface defects were found in the catalyst with higher TPA loadings (55-65 wt.%). The presence of WO x was observed at higher loadings and later agglomerated into tungsten oxide crystals. The TPA impregnated catalysts were investigated for biodiesel synthesis from canola oil. The reaction was found to be independent of mass transfer limitation. The activation energy was 33.6 kJ mol −1 , and preexponential factor was 7.3*10 −2 min −1 . The turnover frequency for the supported catalysts was found in the range of 9.7*10 −4 -8.8*10 −2 min −1 . A conversion of 94.9 ± 2.3% was obtained under the optimized conditions, that is, 10 wt.% of the catalyst loading, 17.5 methanol to oil molar ratio, 4 MPa, and at 200°C in 10 hr.

Potassium and 12‐tungstophosphoric acid loaded alumina as heterogeneous catalyst for the esterification as well as transesterification of waste cooking oil in a single pot

“…In case of 20‐K/TPA/Al 2 O 3 , 4.8 wt% weight loss was noticed up to 100°C owing to the loss of ethanol molecules. Another gradual weight loss step of 5.7 wt%, observed in the range of 100°C–550°C, might be due to the loss of physisorbed solvent molecules and thermal decomposition AlOH bonds 35 . The partial decomposition of hydroxyl group may create the Lewis acidic sites over the catalyst which might be liable for imparting the esterification activity to the catalyst.…”

Production of biodiesel from high free fatty acids content Jatropha curcas oil using environment affable K–Mg composite catalyst

“…The result showed that almost all the JCO was converted into the corresponding ME; thus, the catalyst was noticed very efficient for the transesterification reaction. Kurhade et al reported 94.9 ± 2.3% conversion when the canola oil transesterification was performed using TPA supported gamma‐alumina catalyst at 10 h 26 . Finally, in compared to the above reported work, the present K–Mg (1:2) composite has shown better activity with respect to time.…”

“…It has been concluded that the JCO conversion increased to 99.5% when the reaction time moved from 0.5 to 3 h. The other reaction conditions were kept constant: 6 wt% of K-Mg (1:2) composite with 10:1 methanol to oil molar ratio at 70 C. The result showed that almost all the JCO was converted into the corresponding ME; thus, the catalyst was noticed very efficient for the transesterification reaction. Kurhade et al reported 94.9 ± 2.3% conversion when the canola oil transesterification was performed using TPA supported gamma-alumina catalyst at 10 h. 26 Finally, in compared to the above reported work, the present K-Mg (1:2) composite has shown better activity with respect to time.…”

Solvent Free, Selective Oxidation of Styrene Catalyzed by Cobalt Acylpyrazolone Supported onto Neutral Alumina: Synthesis and Spectral Characterization

“…Neutral alumina exhibits reflection peaks corresponding to the 311, 400, and 440 reflection planes at 37°, 48°, and 66°2θ, respectively, and these reflection peaks are perfectly matched in published papers [40] The ] in an amorphous form on the support (Al 2 O 3 ) surface. [42,43]…”