Paradigm shift in algal biomass refinery and its challenges.

• Social changes on a global scale have challenged the nascent algal industry. • Drop-in fuel would be a new major target of algal lipid-based products. • Enhancing CO 2 fixing efficiency would be a major goal in outdoor cultivation. • An integrated refinery process is required for feasible whole cell utilization. Microalgae have been studied and tested for over 70 years. However, biodiesel, the prime target of the algal industry, has suffered from low competitiveness and current steps toward banning the internal combustion engine all over the world. Meanwhile, interest in reducing CO 2 emissions has grown as the world has witnessed disasters caused by global warming. In this situation, in order to maximize the benefits of the microalgal industry and surmount current limitations, new breakthroughs are being sought. First, drop-in fuel, mandatory for the aviation and maritime industries, has been discussed as a new product. Second, methods to secure stable and feasible outdoor cultivation focusing on CO 2 sequestration were investigated. Lastly, the need for an integrated refinery process to simultaneously produce multiple products has been discussed. While the merits of microalgae industry remain valid, further investigations into these new frontiers would put algal industry at the core of future bio-based economy. [ABSTRACT FROM AUTHOR]