Progress and Challenges in Biodiesel Production from Microalgae Feedstock

Increasing energy demand and limited fossil fuel sources have developed the interest of researchers toward biofuel, as it is regarded as the promising approach for continuous source of energy. Microalgae are considered as a desirable feedstock for biodiesel production due to its inherent capacity to synthesize large amount of oil. The key steps in microalgae biofuel synthesis are cell culture, cell recovery, lipid removal, and fatty acid methyl ester (FAME) production. The high cost of biodiesel production is the major bottleneck in the microalga biofuel technology. Among the four steps, harvesting and lipid extraction count more than 50% of the total cost of biodiesel production. Recently, nanoparticle engineering-based methods have been applied as a powerful tool in algae system to overcome the technical problems. Another problem is the mass cultivation of microalgae, which carries major importance because massive biomass is required for viable production of biodiesel. Closed cultivation system (photobioreactor) and open cultivation system (open raceway ponds) are emerged as a solution for mass cultivation of microalgae, but there is a need to understand the design and principle of cultivation system. In this chapter, a pragmatic and critical discussion is tried to put forward with the ongoing research on microalgae with future trends.