Renewable biofuels from microalgae: technical advances, limitations and economics.

The current world energy crisis and increasing greenhouse gas emissions demand a shift from fossil-based fuels to alternative and sustainable biofuels. The innate potential of microalgae over traditional terrestrial feedstocks to provide a high-quality and sustainable fuel portfolio has been recognized. Microalgae are known to mitigate atmospheric CO₂ and convert it to valuable metabolites and bioactive compounds. The high growth rate of microalgal biomass with no additional requirements of feed and arable land makes microalgae as realistic alternative to existing biofuels sources. Micro-algae can store more primary metabolites under abiotic stress, which can be used as a possible source of energy. These metabolite storing abilities of microalgae have become a point of interest for the scientific community as the accumulated lipids serve as potential feedstock for biodiesel production by transesterification, whereas the carbohydrates can be used as the feedstock for bioethanol production by fermentation. Although microalgae-based biofuels are viable sources of energy, their commercialization and deployment in the fuel market remain a challenge. As a result, efforts are being undertaken to make it more cost-effective. This review describes the microalgae biorefinery method for producing biofuel along with its commercial potential, latest research updates in biofuel research, strategies to improve the algal metabolite content along with the limitations of using algal biomass for biofuels with possible solutions to overcome those limitations. [ABSTRACT FROM AUTHOR]