Sustainable biodiesel production via transesterification of vegetable oils and waste frying oil over reusable magnetic Ca2Fe2O5/CaO@MgFe2O4-Fe2O3 catalyst

Abstract

ABSTRACT The leaching and reusability problem of the catalyst in the catalytic transesterification for biodiesel production led to the poor sustainability and high posttreatment cost. Herein, a reusable magnetic Ca2Fe2O5/CaO@MgFe2O4-Fe2O3 catalyst with high textural stability and good catalytic activity was prepared in this study, and its catalytic performance toward transesterification of five different oil feedstocks was evaluated. Catalyst preparation conditions were optimized and characterizations including scanning electron microscope (SEM), X-ray diffraction analysis (XRD), and so on, were also conducted to investigate the catalytic behaviors. The results demonstrated that the catalyst has good ferromagnetism for magnetic separation, and the presence of synergistic interaction enhanced catalytic activity with all of > 90% biodiesel yield and improved the reusability with > 75% biodiesel yields at the 10th cycle. In addition, the biodiesel yield reached the maximum under the transesterification reaction parameters were optimized, and at the 15/1 methanol/oil molar ratio, 2.5 wt% catalyst dosage, 70°C for 120 min. Further, for biodiesel from five different oil feedstocks, the same composition, all of > 90% yield and the quality that met the American Society of Testing Materials (ASTM) standards demonstrated the strong oil feedstocks applicability and application potential of catalysts.