Cellulosic ethanol makes a stand


ROCK SPRINGS, Pa. – When Americans think ethanol, they think corn. But corn isn’t the only way to get ethanol.
Ethanol can also be made from switchgrass, a grass that is native to the American Midwest and typically found on prairies, roadsides, pastures and in ornamental gardens. Switchgrass is a strong, warm-season grass that can grow almost anywhere in the U.S.
What is it? Ethanol made from grasses or any kind of agricultural waste is called cellulosic ethanol.
At Pennsylvania’s Ag Progress Days Aug. 15-17, scientists presented information about the benefits of cellulosic ethanol and its potential as a renewable fuel source.
Tom Richard, a professor in Penn State’s department of ag and biological engineering, said the process for producing cellulosic ethanol is the same as the process for producing ethanol made from corn.
Turning switchgrass into energy is also a relatively low-energy process. Richard said it is still somewhat difficult to convert switchgrass to energy, but as research progresses, the conversion will become simpler.
Approximately 80 gallons of cellulosic ethanol can be produced from 1 ton of switchgrass.
Current studies have shown the energy needed to produce ethanol – whether from corn or cellulosic biomass – does not exceed the energy it produces.
Ground use. Using switchgrass as a renewable fuel source also allows farmers to take advantage of ground not suitable for other crops.
Although the U.S. doesn’t have any cellulosic ethanol plants in operation, Richard said there are plans to get them started. Canada is also working on this science and has a demonstration plant up and running.
Another benefit of cellulosic ethanol is carbon sequestration.
Carbon sequestration is important because when carbon is released, which is what happens when fossil fuels are consumed, it accumulates in the atmosphere where it has damaging effects.
Studies have revealed significantly more carbon in soil under switchgrass than in soil under other crops. This carbon sequestration is due to things like deep roots, no-till practices and the soil erosion control of the plant itself.
Researchers have also found a use for the lignin produced when switchgrass is converted to cellulosic ethanol. Lignin, a clean-burning material, can be used to power ethanol plants, which makes the production process more energy efficient.
Space considerations. So, if switchgrass is part of the answer to America’s energy woes, do we have enough room for large-scale production?
In 2005, the USDA and U.S. Department of Energy conducted a study that put the available amount of dry biomass at 1.3 billion tons by 2050. This amount of dry biomass would displace about 30 percent of the nation’s current fuel consumption.
Richard assured Ag Progress Days visitors that grain-based ethanol plants won’t go away or become obsolete. Cellulosic ethanol is simply another part of the solution to U.S. energy concerns.
(Reporter Janelle Skrinjar welcomes feedback by phone at 800-837-3419, ext. 22, or by e-mail at jskrinjar@farmanddairy.com.)


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