Microalgal-Based Biorefinery Approaches Toward a Sustainable Future

The formidable upsurge in energy demand along with the current fuel crisis and dwindling fossil fuel reserves, coupled with the alarming increase in atmospheric carbon dioxide (CO2) levels, made it imperative to embrace cleaner and greener energy source to ensure sustainable future of the planet “Earth.” In pursuits of this sustainable goal, microalgae have emerged as a viable solution capable of generating biofuels with lower carbon emission profile such as biodiesel, bioethanol, and biogases such as syngas, methane, hydrogen, hythane etc., along with value-added compounds such as bioplastics, biofertilizer, biochar etc., thus presenting a holistic approach to mitigate global concerns of energy crisis, environmental, and economic security. This chapter critically scrutinizes the production of “microalgae propelled bioenergy” and circular economic behavior of microalgae by employing a cascading approach, thus enabling a versatile biorefinery model. Indeed, by embracing “waste to wealth” paradigm, this approach engenders a synergistic orchestration of production of multiple products, promoting sustainable and efficient resource utilization.