The synthesis of CaO loaded onto Al2O3 from calcium acetate and its application in transesterification of the sunflower oil

Abstract

Transesterification of sunflower oil was carried out over CaO loaded onto γ-Al2O3 as heterogeneous base catalysts. The solid base catalysts were syn­thesized by the modified wet impregnation of calcium acetate monohydrate onto neutral γ-Al2O3, calcined at different temperatures in an inert atmosphere and characterized by FESEM, XRPD and FTIR techniques. The catalyst con­taining 5.5 wt. % CaO supported on γ-Al2O3 calcined at 700°C exhibited the highest FAME yield at mild reaction conditions (60°C, atmospheric pressure, methanol-to-oil molar ratio of 9:1 and 0.51% of active species-CaO by weight of oil). The best CaO/γ-Al2O3 catalyst showed a similar or lower catalytic activity than some other CaO-based catalysts at a smaller amount of the catalyst (at least two times less than in other studies).