They're not just for french fries anymore. Tests have shown that many vegetable-derived cooking and salad oils, such as corn, sunflower and canola, can be made to perform as well or better than the commercial standard for car, boat and machine lubricants.
Svajus Asadauskas, a doctoral candidate working under the direction of J. Larry Duda, chairman of the Department of Chemical Engineering, and Joseph Perez, adjunct professor of chemical engineering, reported that, when blended with a proprietary additive developed at Penn State, some vegetable oil formulations perform as well or better than the commercial standard, 10W-30 SG, in the usual tests for the ability to resist burning and forming deposits at high temperatures. They also performed as well or better than the standards in tests for slipperiness and for evaporation loss.
While the tests examined important but relatively narrow characteristics, Duda notes that one of the group's commercial partners, Renewable Lubricants of Ohio, has also demonstrated vegetable oil's potential by using similar corn oil formulations successfully in company vehicles for the last three years. The company's success challenges the widespread perception that vegetable oils oxidize too rapidly to be used in engines.
Duda said there has been continuing interest in vegetable oil-based lubricants for many years because they are more environmentally friendly. They can be produced and disposed of with less impact on the environment and are cheaper to manufacture than current synthetic lubricants.
Duda adds, "Vegetable oils offer Third World countries with a good farm base a real alternative to importing oil for lubricants."
Highly saturated oils make the best lubricants because of their good stability, Duda said. However, highly saturated oils don't have the fluidity needed in cars, boats and machines.
Asadauskas, a native of Lithuania, is an intern at the U.S. Department of Agriculture (USDA) oil chemical research laboratory in Peoria, Ill.
Perez, who retired from the U.S. Department of Energy about two years ago, is a volunteer faculty member at Penn State. The Penn State Tribology Group, which studies the lubrication of moving surfaces, is the only chemistry-focused tribology group in the U.S.