Biodiesel is getting big! Between 2004 and 2006, use increased ten times, from 25 million gallons to 250 million gallons. Biofuel "fueling point" and advocacy company Propel Biofuels claims
Biodiesel is a clean-burning, domestically-produced fuel, that can be used in any diesel engine with no conversions whatsoever. It is derived from 100% renewable resources like soybeans, canola and mustard seed. Biodiesel delivers equivalent or better engine performance while decreasing harmful emissions by nearly 80%. Grown domestically, it also provides regional farmers with an added revenue stream while decreasing America’s dependence on foreign oil.
Typically, commercially available biodiesel is combined with regular petroleum diesel. Common mixes include B2 (2% biodiesel, 98% regular), B20 and B60, but B100 is available some places -- though usually at noncompetitive prices.
However, one of the tantalizing prospects of biodiesel is the ability for ordinary citizens to create their own fuel. Not counting the hours spent, you can typically make your own for as little as 50 cents gallon. Here's the process as described by Rob Elam (not coincidentally the co-founder of Propel) in his article Making Biodiesel in The Best of MAKE.
1) Filter and de-water (and presumably, de-onion-ring) the oil
2) Determine the acidity of the oil
3) Process the oil with lye and methanol (HEET gasoline additive)
4) Allow to settle and skim off the biodiesel from the waste (glycerine)
Unbiased information might be tricky to find, but if you're interested in learning more, check out this biodiesel basics article on the Union of Concerned Scientists website.
Photo by Rob Elam. (cc)