A small amount of biodiesel added to a tank of regular diesel fuel may help the fuel industry meet lower sulfur standards while improving needed fuel lubricity, according to a University of Missouri researcher.

The Environmental Protection Agency plans to lower the sulfur standard for diesel fuel in June 2006, to reduce emission levels. The new mandate requires diesel fuel with a sulfur level of 15 parts per million, down from the current permissible level of 500 ppm.

In addition to new federal standards, several states, which could include Missouri, plan to mandate the use of a 2 to 5 percent blend of biodiesel fuel.

“Each time the level of sulfur has been lowered, the lubricity of the fuel has dropped,” said Leon Schumacher, associate professor of agricultural engineering. “A lubricity additive may be needed to prevent premature failure of the diesel fuel injection system.”

Number One and Number Two diesel fuels with 15 ppm sulfur that Schumacher tested did not meet lubricity standards set by the Cummins Engine Company and European diesel engine manufacturers, he said.

The addition of 1 percent or more biodiesel raised the lubricity of new Number Two diesel fuel to meet these standards, he said. Additional testing is under way on how biodiesel can affect the lubricity in Number One diesel fuel.

Schumacher said the United States uses 60 billion gallons of petroleum-based diesel fuel for transportation each year. A switch of 2 to 5 percent of that 60 billion gallons to biodiesel would be a substantial reduction in the use of petroleum-based fuel, he said.

Biodiesel can be produced from any type of vegetable- or animal-derived oil including lard, tallow, canola, flax, peanuts, sunflowers, safflower, corn or soybeans — even waste fry oil from fast-food restaurants.

In Missouri, the biggest boost should be for soybean producers. With a glut of soybeans on the market signaling lower prices, the opening of a new market for biodiesel should be good news for Missouri producers, he said. The use of biodiesel fuel should help users as well as producers.

“With as little as 1 or 2 percent biodiesel I am seeing advantages in what I notice in engines' lubricating oil. In used-oil samples, I am finding less wear metals like aluminum, iron, lead and copper,” Schumacher said. “That means the engine should last longer and we could potentially lengthen our oil-change intervals.”


Robert Thomas is an information specialist with Extension and Ag Information, University of Missouri (573-882-2480 or thomasr@missouri.edu).