Albemarle County Public Schools is currently (February 2006) using biodiesel (B20 blend) in several of its school buses in order to evaluate potential operational and environmental benefits of using this alternative to regular diesel fuel.

What is biodiesel? "Biodiesel is a domestic, renewable fuel for diesel engines derived from natural oils like soybean oil, and which meets the specifications of ASTM D 6751. Biodiesel can be used in any concentration with petroleum based diesel fuel in existing diesel engines with little or no modification. Biodiesel is not the same thing as raw begetable oil. It is produced by a chemical process, which removes the glycerin from the oil."

(Source: http://www.biodiesel.org/resources/definitions/default.shtm)

Most commonly, biodiesel is used as a blend of 20% biodiesel and 80% diesel fuel (known as "B20"). B20 can be used in most equipment and applications that use diesel fuel. Biodiesel can also be used in its purest form - 100% biodiesel ("B100") - if proper precautions are taken.

Pros and Cons of Biodiesel Use:

Pros:

• Reduces harmful diesel emissions such as carbon monoxide, particulate matter, hydrocarbons and sulfates;
• Enhances our nation's security by reducing dependence on foreign oil;
• Provides a safe, nontoxic and biodegradable alternative to diesel;
• Can improve lubricity of diesel fuels when used as an additive.

Cons:

• There is a slight increase in nitrogen oxide (NOx) emissions associated with using biodiesel in engines. 
• Biodiesel costs more than conventional petrodiesel.

After considering both the pros and cons, it seems that the environmental benefits of using biodiesel outweigh any limitations, and warrant a close evaluation and consideration for using it in place of diesel.

Related Information and Links:

• The National Biodiesel Board
• Virginia Biodiesel
• US Department of Energy - Biodiesel