Algae-Based Bioenergy Production as a Carbon Mitigation Technology

The looming threat of global warming from various anthropogenic interventions has become increasingly visible globally. The atmospheric carbon dioxide (CO2) concentration, the most prevalent greenhouse gas, crossed 410 ppm for the first time in 2017. Alarmingly, this value further elevated to an all-time high of 420 ppm in January 2023. Even though extensive research has been conducted on developing efficient carbon capture and storage technologies, most are expensive, have a short working life, and impose high environmental impacts. On the other hand, algal cultivation is a green alternative for CO2 sequestration into biomass with derived applications, such as feedstock for producing biofuel, biogas, enzymes, antioxidants, vitamins, biofertilizers, and other value-added products. Additionally, algae-based bioelectrochemical systems (BESs), like microbial carbon-capture cells and biophotovoltaics, are considered more advanced technologies owing to their multidimensional usages, including CO2 sequestration, bioenergy production, wastewater treatment, and valuable product recovery. Therefore, the current chapter comprehensively describes algae-based carbon capture, recent advancements in algal cultivation, and associated roadblocks. Furthermore, this chapter also highlights algae-mediated CO2 capture through BESs, process optimisation, and challenges in the large-scale implementation of these systems.