Sunflower and rapeseed oil transesterification to biodiesel over different nanocrystalline MgO catalysts

Catalytic activity for the production of biodiesel with three morphologically different nanocrystalline MgO materials prepared using simple, green and reproducible methods was investigated. The catalysts were tested in autoclave, microwave and ultrasound conditions. The results showed that working under microwave conditions with these systems led to higher conversions and selectivities to methyl esters, as compared to autoclave or ultrasound, a leaching of the magnesium was evidenced as a direct consequence of a saponification reaction. The results demonstrated that nanostructured MgO could be used effectively as a heterogeneous catalyst system for biodiesel transesterification and the facet of MgO exposed had an important influence regarding activity and selectivity.