ARS Develops "Green" Motor Oil

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What if all of the petroleum-based motor oil now used throughout the country, not only in cars and trucks, but also in every other kind of engine, from ships to lawn mowers, could be replaced with an even better lubricant made from plant oils like canola, sunflower and soy? That tantalizing possibility could one day become a reality, thanks to the work of scientists at the Agricultural Research Service's (ARS) Bio-Oils Research Unit in Peoria, Illinois.

Organic chemists Steven Cermak, Terry Isbell, and their colleagues developed a new kind of bio-based fluid, known as oleic estolides, that is already being used in race cars, and is expected to be commercialized for public use in the next few years.

Although the idea of using plant-based motor lubricants is not a new one, previous efforts by scientists could not overcome several obstacles. Prior bio-based lubricants generally had poor cold-temperature properties, they froze, for example, or particulate formed, clogging up fuel filters. In addition, the earlier lubricants had low oxidative stability and therefore broke down easier.

The estolide oils invented by Isbell and Cermak solve both those problems. They have excellent cold-temperature properties, as well as outstanding oxidative stability properties. Those breakthroughs pave the way for oleic estolides to replace conventional motor lubricants, helping to reduce the nation's dependence on foreign oil.

In addition, the new lubricant has important advantages over conventional petroleum-based and synthetic motor oils, according to Cermak. Because oleic estolides permit the engine parts to move more freely, they don't impose as much wear on the engine, and provide a 10 to 15 percent increase in fuel economy.

Commercializing the estolides was not an easy task. Isbell and Cermak spent endless hours preparing samples, trying to find a partner for a Cooperative Research and Development Agreement (CRADA). They presented their data and findings at numerous meetings and in peer-reviewed scientific journals.

An initial CRADA was signed in the mid-1990s, but the partner decided not to pursue the technology. After the partner agreed to assign its rights to the estolide technology back to the ARS, Cermak and Isbell resumed their search; and in 2006 they entered into a new CRADA with Peaks & Prairies, a small startup owned by farmers in Montana. The ARS has granted the company, recently renamed LubriGreen BioSynthetics, an exclusive license to the estolide patent rights.

In 2011 LubriGreen began commercializing the lubricant, which is currently being used in race cars, a common precursor use for motor oils before they go on the larger market, according to Cermak. LubriGreen has entered into agreements with two large oil companies to distribute the estolide lubricant. The oil companies will buy the base estolide oil from LubriGreen, provide additives, and market their individual brands to consumers, likely sometime in the next few years. LubriGreen has received a substantial investment from one of the companies to continue the research and development process.

In their search for CRADA partners, and in collaborations with them, Isbell and Cermak provided technical assistance for the pilot production of selected products, provided equipment and data transfers, and conducted physical property testing and distillations of estolide materials.

Though some of these tasks might seem straightforward, no prior methods or procedures had been developed for such new materials. Isbell and Cermak had the difficult task of demonstrating, through the use of scientific data, that estolides could not only equal the performance of petroleum-based materials, but exceed them.