What is biodiesel?

Monday, February 2, 2009

Biodiesel is the name of a clean-burning, non-toxic alternative fuel made from vegetable oils that can be used in compression-ignition (diesel) engines. Since soybean oil is the dominant oil produced in the U.S., the development of biodiesel has focused around soy oil. One bushel of soybean produces about 1.5 gallons of biodiesel.

Biodiesel can be used in its pure form, also known as neat biodiesel, or B100. Biodiesel can also be blended at any level with petroleum diesel to create a biodiesel blend. The most common mix is a 20:80 blend of biodiesel to petrodiesel. This blend is called B20.

The name "biodiesel" was introduced in the United States in 1992 by the National SoyDiesel Development Board (now the National Biodiesel Board), which has pioneered the commercialization of biodiesel in the U.S.

What is NOT biodiesel

Blends of biodiesel and diesel fuel. Biodiesel is often mixed with petroleum-based diesel fuel. When 20% biodiesel is blended with 80% diesel fuel, this blend is known as B20. Some people mistakenly believe this blend is biodiesel.

Raw oils: Raw vegetable oil cannot meet biodiesel fuel specifications, it is not registered with the EPA, and it is not a legal motor fuel.

Ethanol-diesel blends (E-diesel)

How is biodiesel made?

Biodiesel is made through a simple refining process called transesterification. The process involves mixing methanol with sodium hydroxide, then mixing that with an oil such as soybean oil. The final products are methyl esters (biodiesel) and glycerine. Glycerine is a valuable material used in the manufacture of soaps and other products.

Methyl or ethyl esters can be produced from vegetable and tree oils, animal fats, and/or used oils and fats.

Some advantages of biodiesel

1. Biodiesel fuel (B100) burns much cleaner than petroleum fuel. The exhaust emissions of sulfur oxides and sulfates, the major components of acid rain are essentially eliminated compared to diesel. Biodiesel is comprised of mid-carbon chains, which burn more completely than petroleum fuel. That is why there is a substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter compared to emissions from diesel fuel.
2. Biodiesel has exceptional lubricating qualities. Use of biodiesel or biodiesel blends have been shown to contribute significantly to the longevity and cleanliness of diesel engines.
3. In new engines, biodiesel fuel consumption is similar to that of petrodiesel. In used engines, fuel economy substantially improves due to continuous cleaning effect of biodiesel.
4. Biodiesel is biodegradable and nontoxic when used in its pure form (B100). For the 20% and lower blends, the diesel fuel portion of the blend determines the toxicity and biodegradability. Biodiesel fuel and fuel blends smell better than conventional diesel - a value to those who work in close proximity to the fuel.
5. Biodiesel is especially promising as a marine engine fuel. As a biodegradable, non-toxic fuel, biodiesel can help prevent damage to marine environments such as wetlands, marshes, rivers, and oceans.
6. Biodiesel is a domestic, renewable resource that strengthens the domestic agricultural economy.
7. The production of soy-based biodiesel has a positive energy balance (as much as 3:1), due to the high energy value of ester-based feedstock's, the low-energy requirements of the conversion process, and the nitrogen-fixing characteristic of soybean.
   

Where to get biodiesel

Biodiesel is available nationwide. It can be purchased directly from biodiesel producers and marketers, petroleum distributors, or at various public pumps.