Biofuel Options Expand as Science Taps New Sources
February 24, 2010
Scientists are making progress in developing biofuels with a range of methods and an assortment of feedstocks. Among the promising clean energy alternatives is an algae photo-bioreactor that grows algae in municipal wastewater to produce biofuel. Developed by the National Aeronautics and Space Administration (NASA), the bioreactor consists of large plastic bags made from a permeable "forward osmosis" membrane. The bags hold the algae and waste nutrients in place while allowing cleansed water to pass through. The bags could potentially be deployed in contaminated and "dead zone" coastal areas, removing excess nutrients while growing algae for biofuels. NASA's Ames Research Center licensed the patent-pending photo-bioreactor to Algae Systems, LCC, which plans to develop and pilot the technology in Tampa Bay, Florida. The company hopes to integrate the technology into biorefineries to produce renewable energy products, including diesel and jet fuel. See the NASA press release.
Researchers are also working with genetic engineering to help find new sources of biofuels. One promising development is testing the use of tobacco as a biofuel feedstock. Recently, researchers from the Biotechnology Foundation Laboratories at Thomas Jefferson University identified a way to increase the oil in tobacco plant leaves, making them a better potential source for biofuel production. Previously, oil-rich tobacco seeds have been tested as diesel fuel, but tobacco plants don't produce abundant numbers of the seeds. so the yield is low. According to researchers, some of these modified plants can yield 20 times more oil than unaltered tobacco, which could make them worthwhile for biofuels. In another novel approach, a team at the University of California, Los Angeles (UCLA) has genetically modified a strain of cyanobacteria, or blue-green algae, to consume carbon dioxide and produce the liquid fuel isobutanol, which holds potential as a gasoline alternative. The reaction is powered directly from sunlight through photosynthesis. See the press releases from Thomas Jefferson University and UCLA.
Other projects are concentrating on using microbes and enzymes to help extract biofuels from biomass. A collaboration led by DOE's Joint BioEnergy Institute (JBEI) has developed a microbe that can produce an advanced biofuel directly from biomass. Researchers from JEBI and biofuels developer LS9 engineered a strain of Escherichia coli bacteria to produce biodiesel fuel, alcohols, and waxes directly from simple sugars. Their new strain of E. coli also produces hemicellulases, enzymes that are able to ferment hemicellulose, the complex sugars that are a major constituent of cellulosic biomass. JBEI is led by DOE's Lawrence Berkeley National Laboratory (LBNL). Along those lines, Novozymes recently launched what it said was the first commercially viable enzymes for production of biofuel from agricultural waste. The enzyme company said its new Cellic CTec2 enzymes could enable the biofuel industry to produce cellulosic ethanol at a price below $2 per gallon for the initial commercial-scale plants that are scheduled to be in operation in 2011. Novozymes has received $29.3 million in DOE grants to pursue biofuel research. See the press releases from LBNL and Novozymes.