Application of Sonication in Lipid Extraction from Microbial Biomass for Third Generation of Biodiesel

Increasing demand in terms of fuel and energy with limited fossil fuels forces researchers to develop renewable fuels in sustainable ways. Biodiesel, as an alternative to mineral diesel, has emerged as one of the potential renewable fuels. With an increasing demand for biodiesel, conventional and non-conventional sources of triglycerides were investigated. In terms of future demand, edible and non-edible sources are insufficient to fulfill the requirement and thus microbial oil will be one of the crucial feedstock for biodiesel production. The extraction of lipids from various biomass is one of the crucial steps in the synthesis of biodiesel, which controls the overall production cost. Over the last few years, conventional lipid extraction techniques such as solvent extraction, mechanical processes, and chemical treatments have been explored, however, all these have their own limitations. Moreover, in order to obtain high purity lipids in an economical way, the use of sonication has garnered much attention in extracting the lipids from the microbial biomass because of the shorter process time, the straightforwardness of the process, and the superior quality of products. It may also lead to reducing the use of solvents in the extraction process. The book chapter deals with the limitations of conventional extraction processes of lipids from microbial biomass and the role of ultrasound in efficient and economic operations. Moreover, to lower the production cost, the application of ultrasound in simultaneous extraction and transesterification has been explored.