Energy Fuels, 2014, by Rhodri W. Jenkins, et. al.
http://pubs.acs.org/doi/pdf/10.1021/ef4022976

"Waste coffee grounds offer a viable waste feedstock for biodiesel production. Approximately 8 million tonnes of coffee are produced globally each year and contain up to 15 wt % lipid, of which the glyceride portion is predominantly made up of palmitic, stearic, oleic, and linoleic acids. In this investigation, the variation in the oil content, saponifiable lipids, and lipid profile according to the regional location and processing or brewing techniques was assessed. A number of key fuel properties were also investigated."