Exploring innovative techniques in algal lipid extraction: Pioneering paths to sustainable biofuel production

The rising need for renewable and sustainable energy sources has brought attention to potential of microalgae as a feedstock for biodiesel production. This review explores innovative techniques in algal lipid extraction, emphasizing advancements that address the challenges associated with traditional methods. In this regard, cultivating high lipid-content algae is pivotal, with genetic modifications and optimized growth conditions playing crucial roles. However, lipid extraction necessitates effective cell-wall disruption, a significant bottleneck due to the robust nature of algal cells. Traditional methods like Bligh-Dyer, Folch, and Soxhlet extraction offer simplicity and high yields; these methods are hindered by toxic reagents, energy-intensive processes, and scalability issues. Evolved methodologies provide promising alternatives with enhanced efficiency and industrial applicability, including bead milling, high-pressure homogenization, ultrasonication, microwave-assisted extraction, and ionic liquid-based techniques. However, they often face challenges such as high energy demands, equipment costs, and environmental concerns. Further, the electrochemical, photochemical, and bio-electro Fenton methods for lipid extraction showed more sustainable outcomes at laboratory scale and further research is required in this direction for upscaling. This review systematically compares the advantages and limitations of various lipid extraction technologies, providing a comprehensive perspective on their feasibility for large-scale biodiesel production. Additionally, it highlights the life cycle analysis of these techniques and identifies future research directions for achieving sustainable algal biofuel production.