Motor Oil of the Future May Come from Veggies

EMBARGOED FOR RELEASE: Monday, March 24, 10:30 a.m., Central Time

Vegetable oil similar to the stuff you use to cook your food may one day fill your car's engine. Researchers at the U.S. Department of Agriculture have developed a chemically modified version of the edible oil that shows promise as a cleaner, renewable alternative to petroleum-based motor oil, while enhancing its protective properties.

Veggie motor oil could eventually be produced cheaper than petroleum-based oil and may help reduce this country's dependence on foreign oil, the researchers say. Their work was described today at the 225th national meeting of the American Chemical Society, the world's largest scientific society.

"Vegetable oil is going to have a huge impact on the future by making the world a cleaner, greener place. Our new version is a significant step in that direction," says Atanu Adhvaryu, Ph.D., a chemist with the USDA's National Center for Agricultural Utilization Research in Peoria, Ill., and a lead researcher on the project.

The new oil could provide a number of performance-enhancing benefits to car engines. In addition to preventing engines from overheating, it offers improved protection from corrosion, better lubrication and improved dispersion of sludge (insoluble byproducts of oil oxidation), which can clog oil filters and lead to engine damage.

The oil could be available to consumers within five years, Adhvaryu says.

Besides car engines, veggie oil and its derivatives also have a wide-range of industrial applications, including hydraulic fluids, lubricants for heavy machinery and functional fluids for processing metals.

Vegetable-based oils have been increasingly used in automotive and industrial applications, mostly as additives to enhance properties of petroleum-based oils. However, they have been limited in application due to their instability at both low and high temperatures. The other drawback has been their cost: Right now, the cost of developing vegetable oil derivatives is much higher than that of petroleum-based oils.

Adhvaryu and his associates have developed a simple, cost-effective method for enhancing the temperature stability of vegetable oil, while retaining its basic chemistry. They chose soybean oil as their starter material, which is available in surplus quantities.

Like other vegetable oils, the soybean oil molecule consists of a triglyceride molecule. The fatty acid chains of the molecule are highly unsaturated, consisting of multiple double bonds, which contribute to the molecule's instability at high temperatures.

Using a newly developed technique, the researchers figured out a way to chemically alter the fatty acid chains in order to reduce the amount of double bonding, creating a more stable molecule. They then added new functional groups to make it even more stable.

The researchers are now working on making chemical modifications to the fatty acid portions of the molecule to make it more stable at low temperatures as well. The resulting product is a vegetable oil molecule that is more stable at both hot and cold temperatures, a key requirement for using it as stand-alone engine oil, industrial fluid and specialty grease. While vegetable oil is a good lubricant in its native form, this property is significantly improved by chemical modification of the oil structure, Adhvaryu says.

The same chemical modification methods developed to improve the temperature-stability of soybean oil can be used for practically any type of vegetable oil, including corn, canola, sunflower and safflower oils, he adds.

Disposing of vegetable oil is easier on the environment because it is so biodegradable, the researcher says. It produces small organic molecules, carbon dioxide and water. The breakdown of petroleum-based oil, on the other hand, produces carbon monoxide -- thought to contribute to global warming -- and unburned hydrocarbons, which are toxic to the environment and harmful to humans.

On a comparative basis, the biodegradability of vegetable oil is generally 90 to 98 percent, compared with 20 to 40 percent for petroleum-based oil, says Adhvaryu. In case of a maritime oil spill or industrial accident, vegetable oil would remain in the environment for a shorter time, he says.

And while petroleum-based oils are limited, non-renewable resources, vegetable-based oil can be developed as needed from renewable plant sources.

Although promising, vegetable oil does have its limitations. It will likely never replace gasoline entirely, which is a petroleum-oil derivative, because vegetable oil is not as flammable by nature, Adhvaryu says.

And unlike the vegetable oil you buy at the supermarket, the new stuff is not edible, he adds.

The USDA provided funding for this study.

The paper on this research, AGRO 14, will be presented at 10:30 a.m., Monday, March 24, at the Hampton Inn-Convention Center, Riverside I, during the "General Papers" symposium.

Atanu Adhvaryu, Ph.D., is an associate research scientist with the USDA's National Center for Agricultural Utilization Research in Peoria, Ill., and a research associate with the Department of Chemical Engineering at Penn State University in State College, Penn.

EMBARGOED FOR RELEASE: Monday, March 24, 10:30 a.m., Central TimeAGRO 14 New triacylglycerol oil with superior low-temperature and thermal stability

Atanu Adhvaryu, Department of Chemical Engineering, Pennsylvania State University / NCAUR, USDA, 105 Fenske Laboratory, University Park, PA 16802 Z. Liu, National Center for Agricultural Utilization Research, ARS-USDA Peoria, and Sevim Z. Erhan, National Center for Agricultural Utilization Research/ARS/USDAOils derived from renewable sources are gaining wide popularity in agricultural, marine, forestry and in certain industrial applications. Natural and genetically modified vegetable oils are limited in application due to their poor low temperature and thermo-oxidative stability. The current research is based on the development of chemical modification methodology for vegetable oil structures to improve these functional properties. The procedure is based on a single-step and two-step synthetic route for converting sites of unsaturation in triglyceride fatty esters to diester functionality. The modification resulted in improving the onset temperature of oxidation (196 degrees C), high temperature insoluble deposit (22 %) and low temperature fluidity (-21 degrees C) compared to regular soybean oil (178 degrees C, 66 % and -6 degrees C), respectively. The resultant vegetable oil derivatives, having diester substitution at the sites of unsaturation, have utility in hydraulic fluids, lubricants, metal working fluids and the like.

EMBARGOED FOR RELEASE: Monday, March 24, 10:30 a.m., Central TimeAGRO 14 New triacylglycerol oil with superior low-temperature and thermal stability*Briefly explain in lay language what you have done, why it is significant and its implications, particularly to the general public.

Vegetable oils in its native form have extremely poor thermal and low temperature stability. Though vegetable oil derivatives have great potential for application as industrial and automotive fluids, their use is highly limited. This research is based on the development of a methodology for chemical modification of vegetable oil to improve the thermal and low temperature properties. This is achieved by creating additional branching sites in the oil structure using a novel catalyst system and an organic group with optimized chain length. Fluids developed by this method still retain the basic vegetable oil structure, highly cost effective and has a potential for commercial production. This work has tremendous impact on the development and supply of eco-friendly industrial fluids based on renewable resources. These fluids match and sometime exceed the performance properties of mineral oil based products currently used in agricultural, industrial, forestry and marine applications. This research has significant impact on the market potential for non-food uses of vegetable oil produced annually in surplus quantity and therefore on the agro-economy.

The unique thing about this research is that the developed fluid still maintain the vegetable oil structure and therefore highly eco-friendly. The fluids developed involve a novel catalytic chemistry and the methodology reported is highly cost effective for large scale production. Fluids developed on vegetable oil thus far are mostly based on ester derivatives of oil and do not possess the inherent benefits of vegetable oil and their associated properties.

* How new is this work and how does it differ from that of others who may be doing similar research?This work has already been submitted for US patent protection.

Corresponding authors name: Dr. Atanu Adhvaryu, Asso. Research Scientist.USDA, NCAUR, 1815 N. University St. Peoria, IL 61604.