Ethanol fuel
Ethanol is commonly used as a fuel source additive and not as a fuel substitute.
Ethanol fuel is ethanol (Ethyl Alcohol or Grain Alcohol), the same type of alcohol found in alcoholic beverages. It can be used as a fuel, mainly as a biofuel alternative to gasoline, and is widely used by flex-fuel light vehicles in Brazil, and as an oxygenate to gasoline in the US. In fact the recent surge in interest for alternative fuel sources is driving research to use Ethanol as a transportation fuel source.
Together, Brazil and USA were responsible for 89 percent of the world's ethanol fuel production in 2008. Because it is easy to manufacture and process and can be made from very common crops such as sugar cane and corn, in several countries ethanol fuel is increasingly being blended as gasohol or used as an oxygenate in gasoline. Bioethanol, unlike petroleum, is a renewable resource that can be produced from agricultural feedstocks.
Anhydrous ethanol (ethanol with less than 1% water) can be blended with gasoline in varying quantities up to pure ethanol (E100). And most modern gasoline engines will operate well with mixtures of 10% ethanol (E10).
For instance, most cars on the road today in the USA can run on blends of up to 10% ethanol, and the use of 10% ethanol gasoline is mandated in some cities where harmful levels of auto emissions are possible.
Ethanol can be mass-produced by fermentation of sugar, or by hydration of ethylene (ethene CH2=CH2) from petroleum and other sources.
Current interest in ethanol mainly lies in bio-ethanol, which is produced from the starch or sugar in a wide variety of crops. But there has been considerable debate about how useful bio-ethanol will be in replacing fossil fuels in vehicles. And concerns relate to the large amount of arable land required for crops, as well as the energy and pollution balance of the whole cycle of ethanol production. Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns.
According to the International Energy Agency, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future than the previously thought. Cellulosic ethanol offers promise as resistant cellulose fibers, a major and universal component in plant cells walls, can be used to generate ethanol.
