The biodiesel community has always been marked by spirited enthusiasm, a clear sense of mission, and the dream that biodiesel could one day play a significant role in our energy future. That dream may soon be a reality. Researchers at Utah State University say that farming algae, with reported oil yields of 10,000 gallons per acre, could become an economically feasible biodiesel feedstock by the end of the decade.
This is the Holy Grail of biodiesel: an oil source that could make a serious dent in our fossil fuel consumption. Our most productive feedstock today, the oil palm, doesn’t even come close with yields of 635 gallons/acre, and is followed distantly by the U.S. standard, soy, at 48 gallons of oil/acre.
Producing biodiesel from algae isn’t a new concept, and it’s easy to see why: algae grow voraciously (measured by the day), algae can proliferate in heinous growing conditions (saltwater or extreme temperatures), and certain species contain up to 60% oil (by weight).
Put quite simply, microalgae are remarkable and efficient biological factories capable of taking a waste (zero-energy) form of carbon (CO2) and converting it into a high density liquid form of energy (natural oil). This ability has been the foundation of the research program funded by the Office Fuels Development.”
Between 1978 and 1996, the Department of Energy (DOE) funded research into technologies that could have significant impacts on the consumption of fossil fuels. The focus of this research became the Aquatic Species Program (ASP), which investigated renewable fuel production (biodiesel) from high-oil algae species, fed by the waste CO2 from coal-fired plants. Researchers whittled down over 3,000 strains of microorganisms into the most productive 300, and constructed 1000 sq. meter test ponds outside of Roswell, NM. The ponds were set up as sort of algae ‘race-tracks’, where algae were circulated around shallow, oval-shaped ponds as carbon dioxide bubbled through the mixture. Results were successful and encouraging, but the program fizzled out after almost 2 decades (a lot of which had to do with a budget crunch and allocating more resources to researching ethanol). Researchers noted that one obstacle to large-scale algae production may be the high cost, which was estimated to be double the price of diesel at the time. (I wonder what they would say now.)
Utah State may finally take this research to the next level. Scientists there plan to produce algae in a grid of indoor bioreactors, with light captured by parabolic dishes on the roof and fed inside via fiber-optic cables. Put several thousand of these bioreactors together and you have an algae farm:
The solar bioreactor utilizes single cell algae, nature’s most efficient means to convert sunshine to biomass, which contain up to 60% oil by weight. To minimize land and water resources, an enclosed bioreactor is used to grow algae on proprietary vertical membranes that resemble library newspaper racks. Harvesting of algae is achieved by periodically flushing water down the membrane from holes in the top ‘rack’. Mature algae are dislodged and collected in a bottom trough while immature algae cling to the membrane and continue to grow. Sunlight is collected and distributed to vertical panels that are sandwiched in close proximity between the growth membranes, much like alternating plates in a car battery. Oil extracted from mature algae can be converted to biodiesel using well established technologies.”
The program has been funded by $6 million in seed money from the Utah Science and Technology Research Initiative, and plans on building the first commercial plant in Utah. USU researchers say algae-biodiesel could become economically feasible by 2009.
Needless to say, this is an exciting project that I will be watching closely.