- Ethanol biofuel is a form of alcohol derived from plants and used as a fuel for motor vehicles. Ethanol can originate from sugar cane, corn, wheat, sorghum or even waste paper. Corn serves as the base of the majority of ethanol produced in the United States.
Because it is derived from plants, one of ethanol's main advantages is its recognition as a renewable resource, as opposed to non-renewable fossil fuels. Theoretically, the same land should continually be able to provide corn or other plants for ethanol production. However, the amount of petroleum-based fertilizers and other chemicals needed to grow crops for ethanol presents a disadvantage. - Ethanol is most often combined with gasoline for use in vehicles. More than 95 percent of the gasoline supplied in the United States in early 2011 contains 6 percent ethanol as a fuel additive. To help replace fossil fuels, ethanol can be used in an 85/15 ratio with gasoline (85 percent ethanol, 15 percent gasoline), known as E85 ethanol. However, only flexible fuel vehicles can use E85.
Ethanol contains a higher oxygen content and so burns cleaner than gasoline, producing fewer greenhouse gas emissions. Ethanol's high octane rating also increases engine performance (see references 1). However, as a disadvantage, ethanol is a less efficient fuel than gasoline, so drivers will need to refuel more often. - Because ethanol is derived from domestically-grown corn in the United States, it is touted as an answer to the United States' dependence on foreign oil. The majority of ethanol produced in the U.S. originates as corn in the Midwestern states. One concern is that land used to grow corn for ethanol is not available to grow crops for food or livestock production. However, if in the future technology exists to produce ethanol from the unusable parts of food crops, a balance between food and fuel production could be reached.
- The cost of producing ethanol fuel is higher than that of petroleum-based fuel, although government subsidies have historically sought to level ethanol's stance in the marketplace. While lower ethanol contents are widely available, E85 ethanol is only readily available in certain regions, most prominently in the Midwest.