RENO, NV --- Researchers at the University of Nevada have concluded that waste coffee grounds can provide a cheap and environmentally friendly source for production of biodiesel fuel.

The new study, published in the Journal of Agricultural and Food Chemistry, describes an approach to "extract oil from spent coffee grounds and to further transesterify the processed oil to convert it into biodiesel."

This process yields 10 to 15 percent oil by weight, depending on whether the coffee is from Arabica or Robusta beans. The biodiesel produced from the coffee grounds was found to be stable for more than a month under ambient conditions. The fuel actually smells like coffee, and is more stable than traditional biodiesel because of coffee's high antioxidant content.

"It is projected that 340 million gallons of biodiesel can be produced from the waste coffee grounds around the world," the study said.

The study authors are Narasimharao Kondamudi, Susanta K. Mohapatra and Mano Misra, who work in the chemical and materials engineering department at the University of Nevada in Reno. They plan to develop a small pilot plant to produce and test the fuel sometime in 2009.