Nonaqueous synthesis of SrO nanopowder and SrO/SiO2 composite and their application for biodiesel production via microwave irradiation

SrO/SiO2 composite was synthesized in a few minutes by reacting Strontium acetylacetonate in benzyl alcohol with mm size SiO2 beads using microwave radiation under argon atmosphere. The current work illustrates the optimization of a one-stage method whereby Nannochloropsis microalgae is converted to biodiesel using direct transesterification by microwave irradiation, the SrO/SiO2 serving as a base catalyst. Microwave radiation accelerates the disruption of the microalgae cells, and eases the release of oil. The SrO/SiO2 has been characterized by thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), scanning electron micrograph (SEM) and dynamic light scattering (DLS). The activity of the catalyst particles in the transesterification reaction was studied using 1H NMR spectroscopy. The catalyst was reused for six cycles without appreciable loss in catalytic activity and the biodiesel yield of the Nannochloropsis microalgae was measured.