Recent advances in microalgal carbon capture and utilization (bio-CCU) process vis-à-vis conventional carbon capture and storage (CCS) technologies.

The rise of the global mean temperature as a consequence of incessant anthropogenic greenhouse gas (GHG) emissions, led by CO2, is one of the direst challenges faced by humankind today. The need of the hour is to minimize fossil fuel usage and capture the atmospheric CO2. Broadly, the CO2 mitigation strategies employ carbon capture and storage (CCS) and biological carbon capture and utilization (bio-CCU) technologies. A critical comparative summary of the prevalent CCS and bio-CCU methods has been presented in this study. Among all the CO2 capture technologies, the microalgal bio-CCU in a biorefinery model is more environment and economy-friendly. Microalgal biorefinery can potentially serve as a platform not only for bio-CCU but also for producing third-generation biofuels and commercially important value-added products as means of wealth generation from waste CO2. Alongside reducing the world's reliance on fossil fuels, this approach also directly or indirectly addresses most of the UN's sustainable development goals (SDGs). To enhance the microalgal CO2 capture efficiency and consequent biomass productivity, smart bioprocess design and reactor engineering performed by researchers are summarized to understand the progress in this direction. Recent advances, innovations, and existing challenges in the design and development of microalgal cultivation processes and systems, including CO2 delivery mechanisms, have been critically discussed and assessed in terms of carbon capture efficiency. The futuristic vision for the fourth-generation microalgal biorefinery-based bio-CCU has also been outlined to make some practical recommendations for its successful implementation or adaptation by the thermal power plants and cement industries. [ABSTRACT FROM AUTHOR]