Preparation of mixed spinel catalyst support (Ca_xMg_1-xAl₂O₄) reinforced by calcium oxide toward in the biodiesel production from vegetable oil

A number of CaxMg1-xAl2O4 supports with different amounts of calcium were synthesized by the solution combustion method. Then, calcium oxide was placed on the support by the impregnation method. The synthesized catalysts were evaluated by various physico-chemical analyzes, and their catalytic performance in a biodiesel production system was probed. The results showed that the addition of calcium to the support could improve the physicochemical properties. The conversion of 93.3% was obtained using optimum catalyst (CaO/Ca0.2Mg0.8Al2O4) at the conditions of 100 degrees C, 12 molar ratio of methanol to oil, 3 wt. % of catalyst, and 3 h of reaction time.