Transesterification of Nannochloropsis oculata microalga's lipid to biodiesel on Al2O3 supported CaO and MgO catalysts.

In this study, we present the activities of Al(2)O(3) supported CaO and MgO catalysts in the transesterification of lipid of yellow green microalgae, Nannochloropsis oculata, as a function of methanol amount and the CaO and MgO loadings at 50 degrees C. We found that pure CaO and MgO were not active and CaO/Al(2)O(3) catalyst among all the mixed oxide catalysts showed the highest activity. Not only the basic site density but also the basic strength is important to achieve the high biodiesel yield. Biodiesel yield over 80 wt.% CaO/Al(2)O(3) catalyst increased to 97.5% from 23% when methanol/lipid molar ratio was 30.