Algae as a Potential Biofuel
Microorganisms Could Fulfill Big Needs for Biodiesel and Ethanol
As high fuel prices and political unrest drive research into alternative fuels, filling your gas tank with goo from your fish tank may one day be possible.
Although usually considered an environmental menace, algae is making waves in the area of biofuel research. As a substance that contains oil and carbohydrates, researchers are turning to this product as a source of both diesel and ethanol.
Ethanol-based biofuels are mainly derived from fermenting the carbohydrates in corn and soy, which are cheap to produce. Raising these crops, however, also requires oil and huge swaths of land that can displace acreage required for food.
Algae, on the other hand, can be grown in areas unsuitable for farming using wastewater and CO2 exhaust from industrial processes.
According to Michael Briggs from the University of New Hampshire Biodiesel Group, the amount of land required to produce enough algae to meet U.S. fuel needs for transportation (or 140.8 billion gallons of biodiesel) would require a land mass of approximately 9.5 million acres. This is a fraction of the acreage used for crop farming (450 million acres) or grazing land for animals (500 million acres).
Fuel research on algae began in 1978 through the U.S. Department of Energy’s Aquatic Species Program, whose goal was to produce biodiesel from algae by growing it in open ponds using leftover industrial CO2. The program ended in 1996, as the technology was too expensive and could not compete with the relatively low oil prices at the time.
A technology still far from refined
According to a January 19, 2008 article in Science Daily, Keith Cooksey, a researcher at Montana State University who was part of the Aquatic Species Program, discovered how to increase oil production from algae in the 1980s and “developed a system that screened algae for their oil content and greatly reduced the sample size needed for their research.”
Recently, many private companies have taken up the challenges of harnessing the power of algae, which include maintaining correct water temperature and CO2 levels.
An article in Popular Mechanics from March 29, 2007 described the efforts of a company called Solix Biofuels to address these problems by moving algae from open ponds to “photobioreactors” (closed structures made of polyethylene plastic) and by forcing carbon dioxide through this closed system.
Selecting the right kind of algae is also a factor, as not every strain will produce the desired amount of oil. Chevron and the US Department of Energy’s National Renewable Energy Laboratory announced in October 2007 that they are working together on this very problem to identify and develop algae strains that can be economically cultivated and processed for fuel.
Don't count your guppies before they hatch
In the right conditions, algae have extremely fast growth rates, and unlike other biofuel crops, they can be harvested on a constant basis year round.
Algae can even grow in wastewater and act as a cleaning agent for that water at the same time. Salinity and desert conditions are also suitable environments, meaning that areas untenable for food crops are perfect for algaculture.
However, as pointed out in a February 5, 2007 article in Technology Review, while some types of algae can produce large amounts of oil, they only do so when starved for nutrients, which then inhibits their ability to quickly grow and reproduce.
Therefore, finding algae with a high lipid content and fast growth rate that is simple and cost-effective to cultivate is still a significant hurdle. And though many scientists and companies have begun jumping on the algae bandwagon, there is still a long road to travel before this promising crop can yield its full potential.
References:
Montana State University (January 19, 2008). "Renewed Interest In Turning Algae Into Fuel Generated". Science Daily. Retrieved January 19, 2008.
National Renewable Energy Laboratory. (July 1998). A Look Back at the U.S. Department of Energy’s Aquatic Species Program: Biodiesel from Algae. Retrieved January 19, 2008.
