"Used grease is worth money? (gasps) Then my arteries are clogged with yellow gold! I'm rich Apu! Rich, I...aaggh! (clenches heart, then sighs) Money in the bank." ~Homer Simpson, Lard of the Dance

Sweet Leviticus, it's true! Common kitchen grease is worth something. You can make biodiesel with it.

Biodiesel is an alternative fuel that can be made from virtually any kind of oil. It works only in diesel engines, which were invented by Rudolf Diesel in 1895. The diesel engine was originally intended to run on a variety of fuels. When it was unveiled at the 1900 World's Fair, it was tested with peanut oil, however, petroleum was cheaper to produce in mass and that has been the staple fuel ever since. In recent years environmental and political concerns have invigorated the quest for alternative fuels and created a viable industry for the production of biodiesel.

Soybean oil is the most common derivative for biodiesel, but it can also be made from canola, peanut, cottonseed, mustard seed or sunflower. Methyl or ethyl is created when the vegetable oil is combined with alcohol and catalyzed with sodium hydroxide at a temperature of about 150 degrees. The only by-product it creates is glycerol which can be used to make soap. In its pure form, it is biodegradable and non-toxic. In the event of a spill, it would disperse quickly and handling is safer due to its high flashpoint. Pure biodiesel, known as B100 or 100% vegetable oil, is not commony used, however. B20 or 20% vegetable oil and 80% petroleum is the most commonly used form.

It has been proven that petroleum burning releases carcinogens into the atmosphere. Prolonged exposure to petrol emmissions can cause cancer due to the presence of polycyclic and nitrated hydrocarbons in the air. Pure biodiesel reduces those carcinogens by 80 and 90%, respectively. However, using anything higher than B20 can invalidate the warranty in most diesel engines even though there is no difference in maintenance and it would actually increase the life of the engine due to its lower viscosity. B100 is also 40 cents to 2 dollars more expensive per gallon than petrodiesel and although the engines require very little upfitting, it is necessary to replace the fuel hoses and seals because pure biodiesel can degrade elastic polymers. Another small problem with biodiesel is that it doesn't like to ignite in cold temperatures and it has a higher freezing point than petrol. Engines in colder climates would have to be stored indoors or fitted with engine block heaters.

There are currently 13 companies in the United States registered to produce and supply biodiesel. 40 states and over 200 government fleets including the United States Postal Service, the Department of Agriculture, NASA and several public transit systems, schools and national parks services are using B20 biodiesel to run their trucks. New legislation spearheaded by the Environmental Protection Agency and the National Biodiesel Board is presented to Congress all the time. The Energy Policy Act of 1992 requires a percentage of all government vehicles to use alternative fuels. In exchange, the municipality is allowed a tax credit for every 450 gallons of biodiesel purchased. Until March 2002, the credits for biodiesel were capped at 50% of total allowable credit. Senators Blanche Lincoln and Christopher Bond from Arkansas and Missouri introduced the biodiesel amendment which would allow a government entity to use biodiesel for all of its tax credits thus increasing the purchasing potential and opening up a wider market for the fuel.

In The Simpsons episode "Lard of the Dance" it was Groundskeeper Willie who had the most formidable stash of grease in Springfield, hidden in the basement of Springfield Elementary. A random choice? I think not. The supplies you need to make biodiesel are:

  • Grease. Check.
  • Methanol. Check. (Willie is Scottish, after all)
  • Sodium Hydroxide. Check. (You can buy it in mass at janitorial supply houses)
  • A working schematic and a handiness with tools to build the processor. Check.

Once again, The Simpsons shows us the way toward a better future.