Microalgal Biorefinery: A Sustainable Technology Toward Circular Bioeconomy and Microalgal Biomass Valorization

Abstract Against the environmental threats caused by anthropogenic activities, there is a soaring interest in circular bioeconomy as a workhorse to maintain human prosperity by securing the full sustainability of our social system. Among the various technical candidates to achieve the plan, the microalgal biorefinery is regarded as the most promising technical model because the concept is able to reap the benefits of both microalgae and biorefinery process simultaneously. Thanks to this, the microalgal technology is considered to possess high versatility and huge environmental remediation ability. In this chapter, the strengths of and opportunities for microalgal biorefinery-driven circular bioeconomy in terms of its systematic components, such as the raw materials, products, and the refinery process, are elaborated. Notwithstanding the potential, many improvements are still needed to confront the refinery technologies’ risk factors and accomplish the realization of microalgal biorefinery-based circular bioeconomy. In this context, while discussing the threats that the biorefinery system confronts, such as underperforming biomass productivity of microalgae and low efficiencies of the process elements, strategies to overcome the weaknesses and plans to increase the contribution of microalgal biorefinery to the circular bioeconomy are suggested.