Algae to Biofuels: Catalytic Strategies and Sustainable Technologies for Green Energy Conversion

The global population surge and continuously rising energy demand led to the rapid depletion of fossil fuel reserves. Over-exploitation of non-renewable fuels is responsible for the emission of greenhouse gases, air pollution, and global warming, which causes serious health issues and ecological imbalance. The present study focuses on the potential of algae-based biofuel as an alternative energy source to fossil fuels. Algal biofuels are more environmentally friendly and economically reasonable to produce in pilot scale over the lignocellulosic derived biofuels. Algae can be cultivated in closed, open, and hybrid photobioreactors. The algal strain along with various factors such as light, temperature, nutrients, carbon dioxide, and pH is responsible for the growth of biomass and biofuel production. Algal-based biofuels offer numerous benefits in terms of socio-economic growth. This review highlights the basic cultivation, dewatering, and processing of algae to produce biofuels using various methods. We also conferred various advantages of an integrated biorefinery system and current technological advancements for algal biofuel production. In addition to this, policies, and market regulations are discussed in brief. At the end, critical challenges and future perspectives of algal biorefineries are reviewed. The algal biofuels are environment friendly as well as economically sustainable and usually offer more benefits compared to fossil fuels.