Calling all chemists! Shelling out too much on gas? If you can make grappa, you can make biodiesel.
Caveat: This isn't child's play. Precise instructions, measurements and materials can be found all over the Internet, but here's a vastly simplified look at the process.
1. On a first-name basis with your local McManager? Time to call in a favour and get some waste grease.
2. Fish out the stuff that isn't waste vegetable oil (WVO), like shoes, cans and last week's Happy Meal toys.
3. Heat the oil. If it starts crackling, you've got water in it that will mess with the process. You'll need to separate it by boiling it off.
4. Time to start transesterification (getting the biofuel). This requires good lye. Depending on your skill, the process could be terrific or terrifying, so check your measurements.
5. Add methanol, and if all goes well, you end up with sodium methoxide, which can cause burns you won't even feel since it takes out your nerves.
6. Heat some more and stir.
7. Let the stuff cool, and in a few hours, if you haven't screwed it up, you'll have biodiesel floating on top of congealed glycerine.
8. Separate the glycerine. Some people boil off the methanol to produce good industrial soap.
9. Wash, dry, drive away a winner (in your pre-converted biodiesel car).
Source: journeytoforever.org