Ten Things You Didn't Know About Biodiesel

With the cost of regular, fossil fuel-based, diesel passing $4.419 per gallon, diesel-dependent drivers across the U.S. are feeling a painful financial pinch, and economy-minded tinkerers are brewing their own biodiesel fuel from used cooking oil.

While you might know you can make your own biodiesel and save on fuel expenses, there are other aspects of biodiesel you might not be aware of. Following are 10 biodiesel facts you might not know:

1. You can use homemade biodiesel in any vehicle with a diesel engine with little or no modification needed. Because it can dissolve engine deposits left by conventional diesel, though, you might have to check your fuel filter more frequently after switching to biodiesel ... at least in the beginning.

2. Rising gasoline and diesel costs are being blamed for a growing number of cooking oil thefts from restaurants across the U.S. Producing biodiesel from used grease costs only about 80 cents per gallon -- less than one-fifth the cost of regular diesel fuel.

3. Because of biodiesel's solvent properties, you need to be careful when using it around painted surfaces. If you spill any on your car's exterior, be sure to wipe it off quickly, or your paint might end up wiping off too.

4. Like any other kind of fuel, biodiesel has a limited shelf life. The National Biodiesel Board recommends that you use any biodiesel you have in six months or less to be sure it works as it's supposed to.

5. You can make your own biodiesel fuel from used cooking oil; any kind -- soybean, sunflower, palm, vegetable, even chicken grease -- will do. Another promising source of biodiesel fuel is algae. In New Zealand, one company has grown algae in ponds of sewage, then pulped the algae to derive the oil that can be converted into biodiesel.

6. Algae-based biodiesel might be the most efficient kind of biodiesel fuel, based on the amount of land required to produce the fuel stock. An acre of algae could yield as much as 1,800 gallons of biodiesel, compared to 90 gallons-per-acre for peanuts or 82 gallons-per-acre for sunflowers.

7. Biodiesel is so far the only alternative fuel that's passed the health effects requirements of the U.S. Clean Air Act. It generates far less particulate and hydrocarbon pollution than fossil fuel-based diesel, though -- if not properly treated with additives or a catalytic converter -- it can produce more nitrogen oxide, a greenhouse gas, than regular diesel fuel.

8. Some 700 major fleets across the U.S. already use biodiesel to power their buses and trucks. Users range from Oregon's Willamette Valley Vineyards and Maine's L.L. Bean to the food services company Sysco and FedEx, which has its own biodiesel fuel station in Washington, D.C. In California, one-fourth of all biodiesel is used by public fleets.

9. Biodiesel is made by adding sodium methoxide to your preferred variety of used cooking oil. As a bonus, a byproduct of the biodiesel production process is glycerin, a key ingredient in homemade soaps.

10. Using homemade biodiesel can be a great way to save on fuel costs and reduce your greenhouse gas emissions, but you could be in trouble with the law if you don't pay state or federal fuel taxes. The requirements vary state by state but, according to the California Center for Sustainable Energy, you're subject to federal taxes if you brew more than 400 gallons of homemade biodiesel. In fact, a retired chemist in Illinois found himself in trouble last year after the state went after him for not paying state fuel taxes for the biodiesel he was making himself.