The urge of algal biomass-based fuels for environmental sustainability against a steady tide of biofuel conflict analysis: Is third-generation algal biorefinery a boon?

To meet the rising demand for biofuel, food, and feed, as well as pharmaceuticals, microalgal-based biorefinery systems provide various advantages. Because of the worldwide energy crises, the future of microalgal biorefinery is attentively receiving prominence. Despite being renewable and carbon–neutral, microalgal-based technology produces net CO2 emissions. Due to poor market pricing for renewable fuels, current biomass conversion techniques are neither profitable nor long-term viable. The microalgal strain chosen is critical to the experiment's success. A comprehensive approach that considers all three aspects of environmental sustainability is required to successfully address these challenges. The process should never be jeopardized in any way that threatens its long-term viability. The issue of sustainability must therefore be addressed from the outset of every biorefinery project. It is necessary to investigate genetically altered microalgal strains with improved lipid content, light usage efficiency, pigment accumulation, and other features during the design phase of an algal-based biorefinery, among other things. This is due to the recent drop in crude oil prices, as well as the significant capital and investment costs associated with algae cultivation. Dewatering, harvesting, and lipid recovery must all be researched and developed at a low cost. To solve the problem of decreasing biomass productivities at bigger production scales, a new generation of photobioreactor designs, lighting strategies, and nutrient feed systems are required. To be successful, proponents of large-scale microalgae-based biorefineries must integrate social and sustainability sciences into their commercial plans. The current review explores the potential application of algal biomass for the production of biofuels and bio-based products. The variety of processes and pathways through which bioconversion of algal biomass can be performed are described in this review.