Published November 2009
The growing energy demand and depletion of fossil fuel resources has created an urgency in the development of alternative energy sources. Such development would reduce the dependence on foreign oil and offer the potential to reduce greenhouse gases. While biofuel technology is gaining momentum in both research laboratories as well as in industry, the economics of making biofuels are challenged by crude oil price fluctuations. Additionally, initial investments into biofuel production technologies such as biofuels from food crops (first generation) and biofuels from nonfood crops (second generation) raised concerns about a rise in the price of food crops and land usage.
Third generation biofuel technologies are now the center of attention. Biofuels from algae appear to resolve the problems associated with first and second generation biofuel technologies. Algae are fast growing organisms that need sunlight, carbon dioxide and water to generate energy that is stored in algal cells in the form of lipids. These lipids can be extracted from algal cells and converted to biofuels such as biodiesel or renewable diesel. Many companies, both small and large, have announced investments into algae biofuel technology. Of these, a major investment announcement worth $600 million was made by ExxonMobil in July 2009. The U.S. government is also supporting this research in the form of grants and tax incentives. While some pilot plants are being built to eventually commercialize the algae biofuel technology, no commercial plant exists today.
In this review, we analyze the technology and economics of 30 million gallons/yr of biodiesel production by a heterotrophic microalgae process, where algae utilize glucose as a fixed carbon source.
This review will be of interest to biofuels producers, technologists, investment communities and government.