Future Methods of Production
Technologies over the years have been increasing the efficiencies of corn/sugarcane-based ethanol production. One issue with corn however, is that it also an important food crop and some fear demand for fuel could raise food prices. Researchers study new technologies that may be more efficient than corn or sugarcane.
Switchgrass and other plant matter
The majority of a plant is not convertible to sugar and potential ethanol fuel is wasted because of this unconvertibility. Research is currently investigating the efficiencise of converting plant matter (biomass) using chemical processes into ethanol. Switchgrass, a plant that grows on the Great Plains in the United States, is under study due to its high cellulose content (Iowa DNR).
Ethanol from non-sugar/starch sources is called cellulosic ethanol. One benefit from using any kind of plant matter is that it is widely avaible; any sort of plant matter can be converted by chemical processes into ethanol. The negative side however, is that the plant matter must be processed into sugars and then processed into ethanol, an additional step that reduces effiencies. According to Pimentel and Patzek, switchgrass-based ethanol production is less efficient that corn based production.
Exotic new method: algae
One method that has been in the media lately is algae-based fuel production. Because algae are simple organisms, they do not use much energy in building structures, as plants do. Current experiments with algae involve finding which species would be the most efficient and suited for the climate a production plant would be in.
The process for algae-based production of ethanol requires a fossil fuel energy station. Power plants that burn coal, oil, or natural gas produce large volumes of carbon dioxide. Instead of releasing the gas into the atmosphere, the gas is first passed through tubes filled with algae, which flourish due to the high amounts of carbon dioxide. This process can reduce the carbon dioxide output of a power plant by as much as 40% andd reduce nitrous oxide emissions by nearly 90% (USAToday). From the algae, an oil that can be used as biodiesel is produced. In addition, the remaining biological matter can be converted into ethanol. Major benefits from this technology also include less demand on land, for the algea are grown in bags or tubes and for the amount of fuel produced, the algae require a fraction of the land corn or other plant-based production woudl require.
Sources
"Biofuels in the US Transport Sector". Energy Information Administration. Feb. 2007. 4 Jan. 2008 http://www.eia.doe.gov/oiaf/analysispaper/biomass.html.
Chawla, Kiran. "Algae Could Provide Ethanol, Biodiesel Fuels". NBC33TV 21 May 2007. 6 Jan. 2008 http://www.nbc33tv.com/news/local/7621026.html.
Clayton, Mark. "Algae — Like a Breath Mint for Smokestacks". USAToday 10 Jan. 2006. 6 Jan. 2008 http://www.usatoday.com/tech/science/2006-01-10-algae-powerplants_x.htm.
"How Ethanol is Made". Renewable Fuels Association. 2006. 5 Jan. 2008 http://www.ethanolrfa.org/resource/made/.
Pimentel, David, and Tad W. Patzek. "Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower". Natural Resources Research 14.1 (2005): 65-76.
"Renewable Energy: Switchgrass". Iowa Department of Natural Resources: Energy. 5 Jan. 2008 http://www.iowadnr.com/energy/renewable/switchgrass.html.