Alternative Fuel Choices Limited For Construction Equipment

By Jeff Griffin, Senior Editor | August 2009 Vol. 64 No. 8

Alternative fuels, including petroleum based diesel and gasoline with additives, are perceived by many to be a key element in reducing world dependency on oil.

Although not without controversy, usage of gasoline/ethanol blends is increasing for passenger cars and light duty trucks. On road diesel trucks can successfully burn diesel fuel/biodiesel blends, and some truck fleets have been converted to liquified natural gas. Research and development of other alternative fuels continues.

Alternative fuels have achieved much less impact on construction sites.

"Currently, biodiesel is really the only viable alternative fuel for use in off road equipment," said Joe Suchecki, director of public affairs for the Engine Manufacturers Association (EMA). "Biodiesel fuels derived from plant materials or waste fats and oils are a viable supplement to the diesel fuel supply derived from petroleum. However, currently there really is not enough production capacity in biodiesel fuel to have a major impact on fuels, and alternatives such as raw vegetable oil or ethanol added to diesel fuel are not recommended."

Suchecki said that biodiesel fuels meeting ASTM specifications can be blended with petroleum based diesel in amounts of up to 5 percent with essentially no issues. Some engine manufacturers have approved higher blend levels for some engine families. Beyond that, there are still issues with biodiesel created using the trans esterification process.

Off road equipment owners considering using biodiesel must evaluate its economics and be prepared to properly store supplies.

Practical
The key word when considering using biodiesel is "practical," said Caterpillar's Martin Willi.

"It comes down to economics and infrastructure," he explained. "For alternative fuels to be practical there must be high volume demands to justify costs of the logistics and storage. Handling guidelines must be carefully followed. Biodiesel cannot be stored for long periods of time because it absorbs water and can oxidize over time. That's a positive from the environmental perspective, but something biodiesel users must take into account."

Most CAT engines burning biodiesel today are able to use a blend of 20 to 30 percent, said Willi.

"CAT engine specifications define what fuels can be used," he said. "So it is important to know the blend and quality of biodiesel being purchased. Until recently in Illinois, it was possible to purchase biodiesel without labeling. Now labeling requirements for blended fuels are in place and that will help. Guidelines for fuel usage are subject to change."