Biodegradable Lubricants Developed from Alternative Crops

Weather patterns, consumer demand and geography all make agricultural business unpredictable. These factors can lead to market gluts, frequently in the wheat and corn sectors. Agricultural Research Service scientists have found a potentially profitable new use for high-oleic oilseed crops, pulling these alternative crops into production.

ARS chemists Terry A. Isbell and Steven C. Cermak made environmentally friendly, effective lubricants containing estolides, which are fatty acids from high-oleic oilseeds, such as high-oleic sunflower and high-oleic safflower. Isbell and Cermak, who are at the National Center for Agricultural Utilization Research (NCAUR) in Peoria, Ill., recently received two U.S. patents on the technology.

The new vegetable-based biodegradable hydraulic fluid is for use in heavy equipment or as crankcase fluid. Industrial-sized production of starting material--the basis for making biodegradable lubricants from sunflower oil fatty acids--was accomplished at a pilot plant at NCAUR.

These lubricants compare favorably to soybean and canola oil, which have also been used to produce biodegradable lubricants. Tests show that estolide-based lubricants pour well in cold temperatures, don’t break down or degrade, and retain their ability to lubricate. The estolide-based lubricants outperform soybean and canola-based products in all of these characteristics, according to Isbell.

However, soybean oil costs only about 13 cents per pound, while oleic acid is 75 cents per pound. But the estolide-based lubricants require fewer additives than traditional vegetable oil lubricants, which makes their final market cost essentially the same.

Their superior properties make estolides good candidates for many lubricant applications, particularly where enhanced performance and biodegradability are required, according to Isbell.

This research was done under a Cooperative Research and Development Agreement (CRADA) with Lambent Technologies of Chicago. The company was acquired in 1998 by Petroferm of Fernandina Beach, Fla.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.