A Simple BioDiesel Experiment

Biodiesel is a diesel fuel that is made by reacting vegetable oil (cooking oil) with other common chemicals. Biodiesel may be used in any diesel automotive engine in its pure form or blended with petroleum-based diesel. No modifications are required, and the result is a less-expensive, renewable, clean-burning fuel. Here's how to make biodiesel from fresh oil. You can also make biodiesel from waste cooking oil, but that is a little more involved, so let's start with the basics.
Materials for Making Biodiesel

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  1 liter of new vegetable oil (e.g, canola oil, corn oil, soybean oil)
  3.5 grams (0.12 oz.) sodium hydroxide (also known as lye). Sodium hydroxide is used for some drain cleaners, such as Red Devil™ drain cleaner. The label should state that the product contains sodium hydroxide (not calcium hypochlorite, which is found in many other drain cleaners)


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  200 milliliters (6.8 fl. oz.) of methanol (methyl alcohol). Heet™ fuel treatment is methanol. Be sure the label says the product contains methanol (Isoheet™, for example, contains isopropyl alcohol and won't work).


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  blender with a low speed option. The pitcher for the blender is to be used only for making biodiesel. You want to use one made from glass, not plastic, since the methanol you will use can react with plastic.


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  digital scale [to accurately measure 3.5 grams (0.12 oz.)]
  glass container marked for 200 milliliters (6.8 fl. oz.). If you don't have a beaker, measure the volume using a measuring cup, pour it into a glass jar, then mark the fill-line on the outside of the jar.


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  glass or plastic container that is marked for 1 liter (1.1 quart)
  wide mouth glass or plastic container that will hold at least 1.5 liters (2-quart pitcher works well)
  safety glasses, gloves, and probably an apron. You do not want to get sodium hydroxide or methanol on your skin, nor do you want to breathe the vapors from either chemical. Both chemicals are toxic. Please read the warning labels on the containers for these products! Methanol is readily absorbed through your skin, so do not get it on your hands. Sodium hydroxide is caustic and will give you a chemical burn. Prepare your biodiesel in a well-ventilated area. If you spill either chemical on your skin, rinse it off immediately with water.

Let's Make Biodiesel!

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  You want to prepare the biodiesel in a room-temperature (70° F) or warmer room since the chemical reaction will not proceed to completion if the temperature is too low.
  If you haven't already, label all your containers as 'Toxic - Only Use for Making Biodiesel', since you don't want anyone drinking your supplies and you don't want to use the glassware for food again.


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  Pour 200 ml methanol (Heet) into the glass blender pitcher.
  Turn the blender on its lowest setting and slowly add 3.5 g sodium hydroxide (lye). This reaction produces sodium methoxide, which must be used right away or else it loses its effectiveness. (Like sodium hydroxide, it can be stored away from air/moisture, but that might not be practical for a home setup.)


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  Mix the methanol and sodium hydroxide until the sodium hydroxide has completely dissolved (about 2 minutes), then add 1 liter of vegetable oil to this mixture.

Continue blending this mixture (on low speed) for 20-30 minutes.

Pour the mixture into a wide-mouth jar. You will see the liquid start to separate out into layers. The bottom layer will be glycerin. The top layer is the biodiesel.

Allow at least a couple of hours for the mixture to fully separate. You want to keep the top layer as your biodiesel fuel. If you like, you can keep the glycerin for other projects. You can either carefully pour off the biodiesel or use a pump or baster to pull the biodiesel off of the glycerin.