Effect of basicity on the catalytic performance of heterogeneous catalysts for biodiesel production

Abstract

In a heterogeneous base methanolysis of vegetable oils one of the most important characteristics of the catalysts are the basicity and the availability of basic centers. The impact of these factors on the catalytic activity was investigated in the reaction of sunflower oil methanolysis by CaO/γ-Al2O3 catalyst. The particle morphology of CaO-dispersed onto γ-Al2O3 surface was analyzed by field emission scanning electron microscopy (FESEM), while basicity and basic strength of prepared catalysts were determined using Hammett indicators method. The results showed a strong dependance of catalytic activity on its basicity. The catalyst with the highest basicity was the most active, and decreasing basicity reduces activity of the catalyst. In addition, it was shown that the catalyst activity depends on the favorable spatial distribution of basic sites, i.e. of their availability.