Chapter 18: Algae
Published:16 Dec 2010
Algae have been and are used as a source of: food, industrial and fine chemicals, pharmaceuticals, nutraceuticals, cosmaceuticals, animal fodder, energy, effluent bioremediation, and fertilizer for the past five thousand years. Algal utilization as a feedstock for biofuel development is not a new concept having been initiated over the past forty years utilizing both macro and microalgae. Utilization of algae as a potential biofuel feedstock, reducing global reliance on petroleum-based transportation fuels, has attracted significant attention. Algal-based biofuels represents many different forms of liquid transportation fuel or energy source including: alkanes, biobutanol, biodiesel, bioethanol, biohydrogen, biomethane, gasoline, green diesel, and jet fuel.
Microalgae or phytoplankton have rapidly gained acceptance as a significant feedstock second-generation biofuel feedstock. Several advantages of microalgae over terrestrial crops include: Large areal productivities and yields (estimates 5000-7000 gallons/acre/year); Short lifecycle; Use of marginal, non-arable land; and Avoidance of feedstock vs. food conflict. Macroalgae or seaweeds represent an alternative to microalgal cultivation as a source of algal-based biofuels exhibiting several advantages including harvesting ease and long-established farming efforts and yielding ∼16 million wet tons per year. Algal-based biofuels stands ready to take its place amongst the evolving second-generation biofuel feedstocks. Incremental biological and technological enhancements along with the development of new methodologies will drive the commercialization of this nascent industry to realize its fullest potential; a significant source of biologically-based transportation fuels.