Study on the solid acid catalysts in biodiesel production from high acid value oil

In an effort to make use of high acid value oils for biodiesel production, various solid acid catalysts such as cesium-doped heteropoly tungstate (CsHPW), 20%TPW/ZrO2, 20%WO3/ZrO2, 20%TPW/γ-Al2O3, and 20%TPW/SiO2 were prepared and evaluated. Leaching of the active species from the catalyst during actual reaction conditions was also investigated to estimate the contribution of homogeneous catalysis. CsHPW was found to be highly active and most stable among other acid catalysts and a maximum conversion of 90% was obtained at the optimum reaction conditions. Further, the recycled use of the selected catalyst was also examined.