A new federal report concludes that the ability to make fuel efficiently from virtually any kind of plant is within reach, offering the promise of a technology that could dramatically benefit the environment, slash dependence on foreign oil, and one day even reorder the global balance of power.
The Department of Energy report, to be released soon, offers a road map for moving from today's technology that makes the fuel ethanol from cornstarch to a new approach using cellulose, the main ingredient in most plants. That would greatly increase the country's ability to produce ethanol, which can easily be used in most automobiles, and create unexpected sources of energy from the rice paddies of California to the paper mills of northern New England.
``I think this is very doable," said Sharlene C. Weatherwax, a program manager in the department's Office of Science, which helped prepare the report. ``This is not a blue-sky exercise for us."
The report lays out an ambitious plan, a kind of Manhattan Project for biofuels, for solving the central obstacle: the high cost of production. The report, prepared in consultation with top scientists in academia, industry, and the government, envisions solving the underlying scientific problems over the next five years, followed by a 10-year program of transferring these advances to industry.
Scientists cautioned that it is impossible to predict how rapidly they will progress, but the report will add momentum to a field that has suddenly become very hot. President Bush called for the development of cellulosic ethanol in his State of the Union address in January, singling out switchgrass, a tall grass that grows on the North American prairie, as a potential source. In the past few months,
Driving the enthusiasm is the high price of oil, which has made alternatives more attractive. But the field itself has been progressing, as new biological tools -- particularly the ability to modify the genetic makeup of organisms -- have made thorny problems seem more tractable. At the same time, leading thinkers from across the political spectrum have come to see dependence on foreign oil as the root cause of many of the nation's challenges.
Fundamentally, traditional fossil fuels and ethanol are plant power. Fossil fuels are plant matter that has been subjected to heat and pressure over millions of years, leaving it in forms that are easy to burn such as coal or oil. This has traditionally been the least expensive option, but it also releases huge amounts of carbon and other materials into the air, causing pollution and trapping heat from the sun in the atmosphere.
Ethanol production turns plant material directly into fuel by breaking it down into alcohol. As plants grow, they remove from the atmosphere the carbon dioxide that contributes to global warming. Today, ethanol is mostly made from corn kernels, but the benefits are modest because the manufacturing process requires a lot of fossil fuels and because of limits on corn production.
For several decades, however, scientists have worked on creating ethanol from cellulose, the long chains of sugars that give plants their toughness, according to Chris Somerville , a plant biologist with the Carnegie Institution and Stanford University who helped prepare the Department of Energy report. Studies have shown this would bring larger environmental advantages because much more fuel could be made using the same amount of energy.
Automobiles on the road today can use a blend of 10 percent ethanol and 90 percent gasoline, but it costs no more than about $200 extra to manufacture a ``flex fuel car" that can use up to 85 percent ethanol. There are already more than 5 million flex fuel cars being driven in the country, and
Veterans of past alternative-energy booms agree that there is palpable excitement now but that this same excitement has come and gone in the past.
``There is no question that interest waxes and wanes based on the price of oil compared to alternatives," said David Barclay , executive director of the Northeast Sustainable Energy Association. Barclay said many alternatives need government financing to be competitive because they are still operating on a relatively small scale.
Cellulose is much more difficult to process than corn kernels, making it prohibitively expensive. The Energy Department estimates that, using current technology, it would cost about $2.26 per gallon to make cellulosic ethanol, according to John Ferrell , an engineer in the department's Office of the Biomass Program, which helped prepare the new study. This estimate does not include the cost of distributing the fuel, which would make it more expensive than gasoline even at the current high prices.
To make ethanol, a manufacturer must break down the plant cell walls using harsh chemicals, then use enzymes that can break down the cellulose into the small molecules of sugar that make it up. These sugars are then fermented by placing them in large vats with microorganisms that convert the sugar into ethanol.
Each of these steps can be made more efficient using a wide range of approaches, especially genetics. For example, plants could be genetically modified so that it's easier to break down the cell wall, getting access to the cellulose.
A number of companies and academic scientists are already working on new solutions. Agrivida , a Cambridge-based start-up created by two MIT graduates, hopes to create genetically modified plants that can create the enzymes needed to break down their own cellulose.
The plants would grow the enzymes so that they are inactive until subjected to high heat, preventing them from degrading the plant while it is still growing, according to R. Michael Rabb , one of the company's founders.
Another company, Mascoma , was founded this year by longtime cellulosic ethanol researcher Lee R. Lynd , a professor of engineering at Dartmouth College in Hanover, N.H. They have created genetically modified bacteria that convert sugars into ethanol at high temperatures, making them easier to use in industrial settings. In March, Silicon Valley venture capitalist Vinod Khosla invested $4 million in the company, which is also supported by Cambridge- based Flagship Ventures .
``The fact that the world is waking up to the need and potential for this technology is very exciting," said Lynd.
Many other companies are involved, and more are expected to join the race. Two enzyme companies, Novozymes and
The enzymes used for corn starches cost about 5 cents per gallon, according to Ferrell. In May, Genencor announced that it is joining a French project to create ethanol from wood pulp.
The Department of Energy has proposed more than doubling the funding for biofuels research and development from this year's $94 million to $190 million next year, a measure Congress is now considering.
Gareth Cook can be reached at email@example.com.