The current global energy demand is met by burning the non-renewable fossil fuels. As the demand is escalating, resources and reserves are diminishing. In addition, the environment is threatened by the continuous emission of greenhouse gases; mainly CO2, which is worrying. Therefore, searching for alternatives is inevitable. Biodiesel received a considerable attention to potentially replace petroleum-based fuels. It can be produced from oil-rich feedstocks through several methods using different technologies, including transesterification. Although alkali catalyzed biodiesel process is commercially viable, several challenges were raised. In this chapter, an overview of the current status of biodiesel production approaches is discussed and the emerging technologies are highlighted. The chapter rewards the attention of using green processes, where the effectiveness of using; microalgae biomass as a green feedstock (compared to conventional crop-based seeds), lipases as green catalysts (compared to conventional chemical catalysts), and green and tunable solvents, such as neoteric solvents and supercritical fluids (compared to conventional volatile organic solvents) are addressed.
Part of the book: Frontiers in Bioenergy and Biofuels