A realistic scenario on microalgae based biodiesel production: Third generation biofuel

Microalgae are the widely employed sources of third generation biofuels, which attracted huge attention by the researchers of the present decade because of their great productivity with lipid content. But to date, the utilization of microalgae for renewable biofuel production is not considered economically viable. The various growth modes employed for microalgal cultivation, such as phototrophic, heterotrophic, mixotrophic, photo-heterotrophic has been compared and conferred in the current investigation. A wide variety of microalgal harvesting techniques that balance energy and economic sustainability is being carried out nowadays. Based on the culture employed, mode and conditions of microalgal cultivation, the choice of bioreactor differs like an open system or closed system bioreactor. This review discusses the basis, key challenges and the future perspective of present-day microalgal cultivation conditions regarding biomass and lipid production. Concurrently the impacts of cultivation mode, bioreactor used for lipid productivity to improve profitable microalgal biodiesel have also been summarized.Department of Science and Technology (DST India) -Promotion of University Research and Scientific Excellence (DST-PURSE) [SR/PURSE Phase 2/38G]; RUSA - Phase 2.0 (Policy (TN Multi-Gen), Department of Education, India) [F.24-51/2014-U]; Scheme for Promotion of Academic and Research Collaboration (SPARC) [SPARC/2018-2019/P485/SL