On January 23, 2007, President George Bush said in his State of the Union Address to the nation: “It's in our vital interest to diversify America's energy supply -- the way forward is through technology. We must continue changing the way America generates electric power …. We must continue investing in new methods of producing ethanol -- using everything from wood chips to grasses, to agricultural wastes.”
The new method of producing ethanol that President Bush referred to in his State of the Union speech is cellulosic ethanol, as opposed to conventional ethanol that is already used in such products as gasoline for our cars. Conventional ethanol is produced from the raw materials of starches, which is obtained from grains that humans eat.
Cellulosic ethanol, on the other hand, is produced from the cellulose of plants. Cellulose is the primary constituent of the cell walls of plants such as wood, grasses, and straw. Since cellulose cannot be digested by humans, the production of cellulose does not compete with the production of food. In addition, land that is not suitable for grain-producing farming can be used for cellulose-producing farming.
Switchgrass (Panicum virgatum), also called tall prairie grass and other names, is a likely plant used to make cellulosic ethanol in the United States because it is a hardy perennial grass. It is already readily available on the North American prairie—growing up to about 7 feet (2.2 meters) in height.
Since cellulose is much more abundant than grains, the price of cellulose is much cheaper. Moreover, since cellulose is the main component of plants, the whole plant can be harvested (in the past, cellulose was often discarded), resulting in better yields for farmers. Cellulosic ethanol can be produced from many different types of biomass (any type of plant or animal materials used as fuel) including those found from agricultural, forestry, and urban sources.
In addition, the production of cellulosic ethanol does not generate very much toxic emissions. According to recent U.S. Department of Energy studies performed by scientists at Argonne National Laboratory, near Chicago, Illinois, cellulosic ethanol was found to reduce the emissions of greenhouse gases by 85% over reformulated gasoline. By contrast, starch ethanol reduces greenhouse gas emissions by only 18 to 29%.
The production of cellulose ethanol has improved recently due to technological advancements. As of June 2006, the price to produce one gallon of cellulosic ethanol, according to the U.S. Department of Energy, is $2.25 ($0.59 for one liter). However, by 2012 the cost of production is targeted to be $1.07 per gallon ($0.28 per liter). Eventually, cellulosic ethanol could at least compete with or maybe even replace gasoline as the fuel of choice for our cars and other petroleum-based devices.
President Bush’s 2007 State of the Union Address is found at: http://www.whitehouse.gov/news/releases/2007/01/20070123-2.html.
More information about cellulosic ethanol is found at: http://www.harvestcleanenergy.org/enews/enews_0505/enews_0505_Cellulosic_Ethanol.htm.