January/February 2001

Mason Chemists on the Road to Alternative Fuel By Lynn Burke Decreased oil production and rising fuel prices are renewing interest in alternative fuels. And researchers in George Mason’s Chemistry Department say one solution is as close as your grocery store shelf--that is, soybean oil. George Mushrush, chair of the Chemistry Department, points to the results of research he and others recently published in Industrial & Engineering Chemistry Research (a publication of the American Chemical Society) on the use of soybean oil as a blending stock for diesel fuel. “The stuff is absolutely wonderful,” says Mushrush. “We’re looking at all that could be bad, and so far [the results have] turned out excellent.” The research was a collaborative effort among researchers at the Naval Research Lab, Geo-Centers Inc., and the university. George Mason researchers include doctoral students Janet Hughes and James Wynn, and undergraduate Joseph Sakran. According to Mushrush, the soybean oil used in the research is the same oil found on grocery store shelves. He says that theoretically you could use the oil to cook french fries, strain it, and then use it again as fuel. The research looked at the use of a blending stock referred to as biodiesel. Biodiesel (chemically called methyl esters) is produced through a reaction of vegetable oil (in this case, soybean oil) or animal fat with methanol in the presence of a catalyst. Just adding 20 percent of the blending stock produces substantial benefits. Diesel fuel alone suffers from stability problems in which solids are formed that can plug nozzles and filters. When the blending stock is added to diesel, the fuel suddenly becomes stable, says Mushrush. The group’s research showed that blends in the 10 to 20 percent concentration range produced much fewer solids than diesel fuel alone and remained stable in storage for at least a year. The researchers also say that adding 10 to 20 percent of the blending stock enhances the fuel’s lubricating properties, which could lengthen the life of fuel pumps and other fuel-handling components. In addition, soybean oil is inexpensive--only $0.17 per pound. Best of all, says Mushrush, the oxygen-rich compounds in biodiesel cause the fuel to burn cleaner, reducing the soot that anyone who has ever been stuck behind a bus in traffic knows all too well. Currently, Ag Environmental Products, the company that produces the biodiesel used in Mason’s research, is marketing the fuel in mass transit areas where air quality is a concern and Energy Policy Act regulations could apply. The company is in the process of having the specification for pure (100 percent) biodiesel approved by the American Society for Testing and Materials. “Soybeans are weather tolerant and easy to grow,” says Mushrush, “and can be grown anywhere from Michigan to Florida.” But, he adds, under current agricultural practices, the use of 100 percent soybean oil as fuel would not be possible simply because not enough soybeans are grown to accommodate the needs of both the food and fuel industries. Production would need to be stepped up. In the meantime, “20 percent is enough to improve fuel and make it less toxic,” he says. Although biodiesel cannot be blended with gasoline or jet fuel because of its molecular weight and its freezing point, Mushrush says it could be used in home heating oil. Biodiesel used in home heating oil yields the same benefits as when used in diesel: It is more stable, less expensive, and cleaner burning. For homeowners with leaky underground oil storage tanks, Mushrush believes the use of a less toxic oil could play a role in future remediation efforts.