Coffee grounds can be a source of biodiesel.
Mano Misra, a professor of engineering at the University of Nevada, Reno, stumbled across a discovery that coffee naturally contains oil as he looked into his leftover coffee cup. Coffee grounds contain 10 to 15 percent oil by weight and Misra realized that it could be a likely candidate to provide a viable supply of biodiesel. You can make biodiesel at a cost of only $1 per gallon if you reclaim coffee grounds.
Instructions
Separating Oil from Coffee Grounds
1. Dry the used coffee grounds by thinly spreading them on a clean surface. A couple of hours can be enough to dry the grounds if spread thinly enough.
2. Separate the coffee grounds from its oil with a Soxhlet extraction apparatus with recovery distillation accessory. Pour a small amount of hexane into the flask on the side of the Soxhlet apparatus.
3. Boil liquid hexane in the bottom of the flask.
Separate the Hexane from the Coffee Oil
4. Allow the coffee grounds in the apparatus to fill with hexane five times, which takes about 10 minutes each time. The hexane-coffee oil mixture will become lighter in color as the oil is separated.
5. Extract the coffee oil from the hexane and reclaim the hexane by distilling the hexane out of the hexane-coffee oil mixture. Run cold water through the side arm of the apparatus and it will condense the hexane vapor so that it drips into a collection flask on the side of the apparatus.
6. Surround the collection flask with ice to keep the hexane in a liquid, not gas form.
Tags: coffee grounds, Coffee grounds, collection flask, flask side, from Coffee, hexane-coffee mixture, side apparatus