Microwave-Assisted Biodiesel Production from Microalgae, Scenedesmus Species, Using Goat Bone-Made Nano-catalyst

The production of biodiesel from Scenedesmus algal oil is one of the best alternative forms of liquid fuel production from biomass to petrol diesel. Biodiesel plays a significant role in the carbon sequestration process during cultivation. Scenedesmus algal species was isolated and cultured in a bold basal medium by using nonheat releasing white florescence (2500 lx) for a 12:12-h dark and light cycle. Algae oil was extracted from dried microalgae biomass through a microwave digester-assisted solvent extraction method. Consequently, about 20.8% algal oil per gram was obtained. A waste-based calcium oxide (CaO) nano-catalyst prepared from goat bone was used in the transesterification process. The catalyst was calcinated at 900 °C and characterized using FTIR, SEM, EDX, and XRD techniques. The results revealed a mean particle size of 43.96 nm with an irregular shape, porous structure, and possession of many active sites. The optimized transesterification process offers an optimum biodiesel yield of 92% at the experimental conditions, i.e., at a reaction temperature of 60 °C, 2% (Wt.) catalyst loading and 11:1 methanol to algal oil molar ratio, 1500 rpm stirring speed, and 3 h reaction duration. The physicochemical properties of the produced biodiesel were tested according to ASTM D6751 standards and are in good agreement.