Renewable Fuels: Ethanol and Biodiesel


Ethanol
Ethanol is a high-octane, water-free alcohol produced from renewable resources such as wheat, corn, sugar cane, straw, wood or other bio-materials. Ethanol is most often blended with gasoline, usually at ratios of up to 10 percent of the total mix. The result is a clean-burning fuel.

Already, ethanol and biodiesel have become a significant part of the global energy equation. As early as 2004, it was recognized that the unprecedented growth in U.S. ethanol production made it the single most important and fastest growing value added market for farmers everywhere. Moreover, while helping to increase the quality of the air we breathe, the introduction of biofuels has also helped to reduce the consumption of fossil fuels.

Today, ethanol remains as the best near-term instrument for reducing greenhouse gas emissions from vehicles. The insatiable demand for octane and clean-blending components to replace MTBE in gasoline has made ethanol a regular ingredient for motor fuels. In reality, refiners would probably embrace ethanol even if federal oxygenate standards did not mandate its use. The octane in ethanol is that good.

Ethanol has made the transition from the niche fuel or curiosity it was at its humble beginnings in the 1970s to its current position as a standard gasoline component valued for its octane and oxygen content. Billions of gallons are now produced annually.

Biodiesel
Biodiesel is a clean-burning alternative fuel, produced from renewable resources. It contains no fossil fuel ingredients, but can be blended with petroleum diesel to form a biodiesel blend. This product can then be used to power compression-ignition (diesel) engines with only minor or no modifications.

Biodiesel is biodegradable, nontoxic, and effectively free of sulfur and aromatics. Biodiesel, in simple terms, can be produced from any fat or oil such as soybean oil, through a refining process. Fuel-grade biodiesel must meet strict industry specifications (ASTM D6751) in order to ensure proper performance. This alternative fuel also meets Environmental Protection Agency standards as a legal motor fuel for sale and distribution. In contrast, natural vegetable oils cannot meet biodiesel fuel specifications.

A biodiesel blended with petroleum diesel (20 percent biodiesel / 80 percent petroleum diesel) produces measurable environmental benefits with a minimum increase in cost for fleet operations and other consumers. Biodiesel is approved for use in the United States. In 2006 alone, it is estimated that as much as 250 million gallons were sold on the domestic markets.

A primary advantage of the use of biodiesel is to substantially reduce unburned hydrocarbons, carbon monoxide, and particulate matter in conventional diesel engines, compared to emissions from diesel fuel.