From Fryolator to Fuel Tank, Waste Cooking Oil Powers Jetta

Listen to the UVA Today Radio Show report on this story:

May 1, 2009 — Keith Williams' car fuel is a waste.


Williams, a University of Virginia physics professor, runs his 2005 Volkswagen Jetta on fuel derived from cast-off cooking oil at Hereford College, formulated as part of a class project.

A resident professor at Hereford, Williams had been burning waste oil for motor fuel for about a year before he decided that generating the fuel might make a good topic for a short course. 

"At first I was just going to take the short course," said Pin-Hsuan "Katy" Lai, a first-year student and Hereford resident who is one of the dozen students enrolled in Williams' non-credit course. "But after I got my hands-on experience, I could see how we could take a waste product and make something useful out of it."

Williams and his students run about 20 gallons of waste cooking oil from Runk Dining Hall each week through a centrifuge to filter out particles. They then heat it to burn off any water, rendering the oil clean enough to propel a diesel vehicle.

"We could expand it so people at U.Va. could run it in their diesel vehicles," said Lai, who is considering a business or environmental major.

Rebecca White, director of the Department of Parking and Transportation, made a presentation to the class, detailing what her department has done with biodiesel.

Converting used cooking oil "is not pulling something out of the food stream, such as some of the corn-based fuels," White said.

While the waste oil fuel is not feasible yet for the bus fleet – in part due to conversion costs – White said she might run a few of her department's other vehicles on it.

Williams purchased a $1,000 kit to convert his diesel to run on vegetable oil, which included adding a second fuel tank to his car. He needs regular diesel fuel to start the Jetta, since the waste oil is too viscous when cold; once heated, though, it runs fine in the car. (The viscosity issue would be a problem for the buses, White said.)

Williams has seen no fall-off in his car's performance since the conversion and is still getting about 50 miles per gallon, comparable to the mileage he was getting on regular diesel fuel.

The waste cooking oil burns cleaner, Williams said, without the sulfur emissions that are a byproduct of both regular diesel and bio-diesel.

"This saves on the cost of fuel and also reduces the environmental impact," Lai said.

The students are trying to promote their alternate fuel efforts. Lai and Anna Pfieffer, another first-year student, created a video slide show on the project and have commissioned T-shirts bearing a logo they designed.

Pfieffer said the course has changed her thinking. "I definitely have a harder time throwing things away," she said. "I look at trash with a whole new prospective of what it could be used for."

The students would like to see their video spark creativity in others. "I hope that it can be used to educate others on what we did in our research and get people to see that with creative thinking you can turn a waste product into a treasure," Pfieffer said.

Williams said there are many potential applications for the cooking-oil fuel. He is considering converting a lawn mower to run on it, and it would also work as a home heating fuel, he said, adding that it would burn easier in a furnace than in a diesel engine.

Williams obtains, processes and uses the fuel locally, which he said fits nicely into the "buy local" movement. It also can help local restaurants that normally pay to have their waste cooking oil hauled away, said Brent Berringer, director of University Dining Services, which purchases about 128,000 gallons of cooking oil a year, of which about 102,400 gallons is later removed as waste oil.

Aside from the start-up costs of purchasing the equipment such as the centrifuge, Williams uses electricity to heat the oil so water will evaporate. Now he is weighing solar options.

"We are looking at building a solar collector to heat the oil without pulling any power off the grid," Williams said.

— By Matt Kelly