Equipment
There are several suppliers of biodiesel kits (see Resources). Before purchasing any kit, research the kits carefully, and be comfortable with making small batches. Some farmers will already have all of the equipment. For safety, a completely closed system is best. There are several how-to references available for making a closed-system biodiesel reactor. This publication describes a simple open-system method to be used by a responsible adult with proper safety equipment.
To make a small batch of biodiesel from new oil, you will need the following.
A blender with a glass jar. (These are available at second-hand stores for a few dollars) or a glass jar with a tight fitting lid to use to shake the reactants. Note: After using the blender or jar to make biodiesel, do not use it for any food preparation. Also note that the biodiesel will dissolve any natural rubber. The seals that come with the second-hand blender will probably not last too long. You can cut new seals out of Teflon sheeting available from auto parts stores.
- A scale that can weigh 0 to 50 grams to the nearest 0.1 gram.
- One quart jar.
- One-cup liquid measuring cup (glass or plastic compatible with methanol).
- A hand pump. (Inexpensive pumps are available at cleaning supply stores.)
- Vegetable oil.
- Methanol.
- Sodium hydroxide (lye).
Method
Have all the materials warm, room temperature at the coolest, 130°F at the warmest. Put on the respirator, goggles, and gloves (See Hazards! box). Place 1 fluid cup of methanol in the blender. Measure out 3.5 grams of sodium hydroxide from a new container and place it in the methanol in the blender. Put the top on the blender and blend on low speed for about five minutes. Shut off the blender. The mixture in the blender is now sodium methoxide, a strong base. Avoid getting this on anything, especially yourself.
Measure one quart of new vegetable oil and pour it into the sodium methoxide in the blender. Put the lid on (you may now take off the respirator, gloves, and goggles) and blend at low speed for a half hour. Let the mixture settle at room temperature for at least eight hours. The mixture is now composed of light-colored methyl esters (biodiesel) floating on top of heavier, darker glycerol. Using the hand pump, pump the light biodiesel off of the glycerol.
The resulting biodiesel can be used in oil-fired heating equipment or some oil lamps. Some people use biodiesel at this stage in diesel engines; I recommend washing the biodiesel (see Washing Biodiesel, below). The glycerol can be used to make soap, or it can be poured into a pan, left to dry-out for a week or so, and then put into a compost bin. Glycerol can also be burned as a fuel; see Glycerin Uses in the Resources section.
If you were not successful, make sure you follow the recipe exactly, and try again. Unsuccessful batches can show up in a variety of ways, but if you are using new oil, a batch can fail because you didn't use almost pure methanol, you used old sodium hydroxide, you did not mix the solutions long enough, or the temperature was too low. If you do not have two distinct layers in the blender, you probably did not use enough sodium hydroxide. If you have a solid white material in the blender, this is soap. Study the How-To Resources for help in figuring out what went wrong and how an unsuccessful batch may be remedied. Get comfortable making small batches before moving up to a larger batch.
