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Features April 11, 2003  RSS feed


Powering a Car on Waste Vegetable Oil

By David Henri, New Hartford


I converted my 1981 diesel VW Rabbit to run on free waste vegetable oil from restaurant fryers. I get an exhilarating feeling of freedom from going down the road running on this renewable fuel.

When Rudolf Diesel invented the diesel engine, he designed it to run on peanut oil. It was soon discovered that it would operate on cheaper petroleum oil. Today diesel engines will run, with a little modification, on peanut oil as well as on the oils of canola, soy, corn, sunflower, safflower, palm, olive, coconut, hemp, cottonseed, sesame, and many others.

These oils burn much cleaner in a diesel engine than diesel fuel. They emit no sulfur, and thus do not contribute to acid rain. The carbon released is what would have been released naturally from the decay of the plant matter used. Therefore it is carbon-neutral, releasing carbon that was captured a year or two ago, and that carbon will be again absorbed in next year's crop. Fossil fuels, on the other hand, release carbon captured millions of years ago, upsetting the atmospheric balance and causing global warming. Another benefit is that the particulate matter emitted from running on vegetable oil is way lower than diesel fuel. Gone is the obnoxious diesel smell and black smoke, replaced with the smell of cooking oil. So if you are following me as I tool around town and suddenly get hungry for fish and chips, that’s why. Also, any veggie oil spills are biodegradable.

Politically, vegetable oil is a correct fuel to use. It requires no deployment of troops to "protect" vital oil interests in foreign lands. It isn’t tainted by Big Oil lobbies and campaign contributions. It keeps money from going to the Middle East. It makes people more free, not only here but globally. It can be made from crops grown and pressed locally, an ideal use for open space.


The heated vegetable oil fuel filter.The heated vegetable oil fuel filter.

Waste vegetable oil is a very economical fuel to use. It is recycling something that was used up. Restaurants pay to have it removed, so they give it to me gladly. I’m accustomed to smelling fast food—now I smell free renewable fuel! It’s like manna from heaven.

Now that you know why I converted my car, here is a general explanation of how I did it. Waste vegetable oil needs to be filtered well before being used. Veggie oil also needs to be heated to run through the injector pump and fuel injectors on a diesel engine. This is accomplished by using heat transferred by engine coolant from the engine. In my trunk I have a separate fuel tank for veggie oil. It’s heated with a copper coil inside the tank that has hot coolant running through it. The veggie fuel line runs inside the heater hose that delivers the coolant to the tank. It is a hose within a hose, heating the oil as it heads towards the engine. There is a separate fuel filter that’s wrapped in a copper coil that also has hot coolant circulating through it, heating the veggie fuel in the filter.

In order to get the oil hot enough to flow (and run), I need to use diesel from the regular tank and fuel system to warm up the car. After a few miles I switch over to veggie by using an electric fuel selector switch mounted on the dashboard. The car seems to run better on vegetable oil. A few miles before I stop I turn back to diesel to clear out the veggie oil from the pump and lines, so that it does not congeal. Eventually I’ll use biodiesel instead of diesel for warming and stopping, and then I won’t be using any fossil fuels.

Biodiesel is diesel fuel made from vegetable oil, chemically altered to be very close to regular diesel fuel in composition. It’s the other option for folks who do not wish to convert their car to run on veggie oil. Just get some biodiesel and pour it into your regular diesel tank; this fuel does not need to be heated. It can be delivered to your home in 50-gallon drums. No need to worry—it’s nontoxic, biodegradable, and has a higher flash point than home heating fuel. There is currently not any place to buy biodiesel from a pump in Connecticut, but there is a biodiesel co-op in Southington that delivers to members (for more info go to <ctbiodzl.freeshell.org>). It costs around $2.50 a gallon. The people who use it mostly drive VW TDI’s (turbo-diesel models) that get 50 miles to a gallon, meaning that they are paying about 5 cents per mile for fuel. (The driver of a typical car that gets 25 miles per gallon at $1.75 per gallon for gasoline spends 7 cents per mile for fuel.)


The veggie oil tank in the trunk.The veggie oil tank in the trunk.

Biodiesel can be made locally from waste vegetable oil. I made a small amount, but it uses some nasty chemicals that I didn’t like working with. Take some methanol and mix it with lye, in the proper proportions, using safety precautions. Mix that mixture with veggie oil and start a chemical reaction; the products are biodiesel and glycerin. Do not try this without getting the book From the Fryer to the Fuel Tank by Joshua Tickell. Available at <www.veggievan.org>, this book is also required reading for anyone who wants to convert a diesel car to run on veggie oil.

The use of biodiesel and straight vegetable oil is growing. Biodiesel can be mixed with diesel for a much cleaner-burning fuel. Many towns are starting to run these mixes in school buses for the better health of their children.

Want to join the veggie oil movement? Get yourself a diesel and convert it, or join the CT Biodiesel Co-op. There are kits available at <greasel.com>. Give me a call at 860-489-9555, and I’ll be glad to help.

Two percent of the passenger cars in the United States are diesel; there is enough waste veggie oil to run a lot of these. Also, you can power your home with biodiesel and a diesel generator. In Europe, 30% of the cars are diesel, and European farmers are growing rapeseed (canola) for the production of biodiesel. Fields of yellow flowers instead of oil fields—now that’s a choice we can live with.