Microalgae conversion to alternative energy, operating environment and economic footprint: An influential approach towards energy conversion, and management

Microalgae (MA) biorefinery is a vital platform for the conversion of biomass into biofuels, biomaterials, and bioactive substances and it can remediate the pollutant from the environment. Moreover, its commercialization can enable a jump start towards resolving energy and economic crisis. However, the major bottleneck in biorefinery includes (i) low biomass and biomolecules production, (ii) high cost, (iii) less economic viability, (iv) high energy requirement, and (v) environmental impacts of the process. Furthermore, the lack of advanced models or algorithms for process designing and limited genetic and molecular knowledge is a key bottleneck. Thus, there is an urgent need for novel integrated microalgal bioenergy conversion methods that provide economic and environmental balance. Moreover, advanced molecular knowledge in the microalgal research pipeline can be developed that improves the biosynthesis of biomolecules. Furthermore, novel technological development is required that automatically controls and monitors the microalgal biorefinery. Thus, the current review describes a comparative analysis of the gaps from previous studies. Subsequently, it highlights advanced cutting-edge cultivation and molecular and genetic approaches for enhancing biomass and biomolecules. It critically evaluates the potential of artificial intelligence (AI) algorithms and IoTs-based sensors used in microalgal cultivation, system optimization pipeline, and other aspects. Finally, it aims to provide a conceptual scenario and integrated mechanisms of multiple biofuel production with co-products formation concerning zero-carbon and waste footprint to maintain a circular-bioeconomy. Additionally, it also offers elaboration on recent life-cycle-assessment (LCA), techno-economic analysis (TEA) of recent microalgal biofuels biorefinery, and algal biofuels' current and future market trends towards sustainability key challenges and opportunities. This review will contribute critically to the novelty and significance in the field of microalgae biorefinery to develop smarter, safer, cleaner, greener, and economically efficient techniques for exhaustive energy recovery tactics and pathway to a digitalized the future of MA biorefinery.