Biodiesel as a transportation fuel

A bus powered by soybean oil
A Bus Powered by Soybean Oil

Source: Stock photography (copyrighted)

Most of the trucks, buses, and tractors in the United States use diesel fuel. Diesel fuel is a nonrenewable fuel made from petroleum. Using biodiesel fuel produces less pollution than using petroleum diesel fuel. Any vehicle that operates on diesel fuel can switch to biodiesel without making changes to the engine.

Biodiesel fuel has chemical characteristics similar to petroleum-based diesel, so it can be used as a direct substitute for diesel fuel. Biodiesel fuel can also be blended with petroleum diesel in any percentage without losing fuel economy.

Biodiesel blends

A blend of 20% biodiesel with 80% petroleum diesel is known as B20. Low-level biodiesel blends like B2 and B5 are popular fuels in the trucking industry because biodiesel has excellent lubricating properties, so usage of the blends can benefit engine performance.

Pure biodiesel (often called B100) and biodiesel blends are sensitive to cold weather and may require a special type of anti-freeze, just like petroleum-based diesel fuel. Biodiesel acts like a detergent additive, loosening and dissolving sediments in storage tanks. Because biodiesel is a solvent, B100 may cause rubber and other components to fail in older vehicles. This problem does not occur with biodiesel blends.

Biodiesel use has increased substantially since 2001

Because of biodiesel's environmental benefits, ease of use, and available subsidies, biodiesel use in the United States grew from about 10 million gallons in 2001 to 358 million gallons in 2007. Consumption dropped to about 320 million gallons in 2008 and in 2009, but production continued to increase through 2008 to meet strong export demand. Consumption dropped to about 263 million gallons in 2010, as the federal excise tax credit for biodiesel blending expired. In 2011, the tax credit was extended for one year, and substantial quantities of biodiesel were needed to meet the Renewable Fuels Standard. These factors caused biodiesel consumption to increase to 887 million gallons in 2011. Consumption declined to about 870 million gallons in 2012, and then increased to nearly 1.4 billion gallons in 2013 and 2014.

Biodiesel at blend levels of 5% by volume (B5) or lower can be used in any diesel engine. Some use of biodiesel at blend levels of 20% by volume (B20) occurs with fleet vehicles such as school and transit buses, snowplows, garbage trucks, mail trucks, and military vehicles. Some fleet use of biodiesel blends is required by federal or state mandates. There are public fueling stations that offer biodiesel blends for sale to the public in nearly every state.

In 2012, 6.44 billion gallons of biodiesel were consumed in about 64 countries; 54% was consumed in five countries.

World biodiesel consumption, 2012

  Billion gallons Share of total
World total 6.44  
United States 0.92 14%
Germany 0.75 12%
Brazil 0.74 11%
France 0.66 10%
Spain 0.42 7%
All others 2.96 46%