Divulging the future of sustainable energy: Innovations and challenges in algal biodiesel production for green energy

Abstract

Algae, often hailed as the tiny superheroes of the aquatic world, have garnered significant attention for their ability to produce sustainable and eco-friendly biodiesel, presenting a promising alternative to traditional fossil fuels. This review examines the current state of algal biodiesel production, addressing key challenges such as strain selection, high production costs, and environmental impact, and proposing solutions to guide future research in renewable energy. The production process typically involves open raceway ponds or closed photo-bioreactors, followed by harvesting, drying, and lipid extraction, with innovative methods like ultra-sonication in situ synthesis offering high-quality biodiesel. The review clarifies the roles of catalysts in the transesterification process and fatty acid methyl esterase (FAME) generation and stress-induced production, as well as the distinction between direct and indirect transesterification methods. The heterogeneous catalysts in transesterification have improved the purity of biodiesel and decreased processing times, while genetic modifications and nanotechnology-like innovative methodology have increased lipid production. According to economic estimates, high production costs remain a hurdle if the worldwide algae biofuel industry is estimated to be worth USD 8.38 billion in 2022. However, the financial viability may be enhanced by the co-production of value-added products (VAPs), projected to reach USD 53.43 billion by 2026. Despite significant advancements in the field, this paper showed the widespread adoption of algal biodiesel as a sustainable energy source using genetic engineering, coagulation-flocculation, synthetic biology, and biorefinery-based production to overcome technological and economic constraints focused on the last. Strong regulatory support and ongoing innovation are necessary to achieve large-scale viability.