Scientists at the University of Nevada, Reno, have made diesel fuel from used coffee grounds.
The technique is not difficult, they report in The Journal of Agricultural and Food Chemistry, and there is so much coffee around that several hundred million gallons of biodiesel could potentially be made annually.
Analysis showed that even the grounds contained about 10 to 15 percent oil by weight. The researchers then used standard chemistry techniques to extract the oil and convert it to biodiesel. The processes are not particularly energy intensive, Misra said, and the researchers estimated that biodiesel could be produced for about a dollar a gallon.
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