How to Make Biodiesel From Soybeans

by Faith Davies

In today's world, biodiesel fuel is very appealing. It burns cleanly and can be made by unwanted or wasted organic material, helping the environment and saving energy. With the rising cost of oil and gasoline, many consumers and businesses are eager to make the switch to biodiesel to run their diesel-powered vehicles, generate electricity or heat their homes or commercial buildings. Many people are interested in ways to produce biodiesel fuel for their own consumption. One way to do this is through the use of soybean-based oil.

Making Biodiesel from Soybean Oil

Step 1

Pour the methanol into the plastic container, using the funnel. Add the lye through the second funnel. Place the top on the container and swirl it until the lye is dissolved.

Step 2

Heat the soybean oil to130 degrees F.

Step 3

Pour the heated oil into the blender, add the core chemicals and blend on the lowest setting for 30 minutes. Be sure to use a spare or secondhand blender and not one you intend to use for food.

Step 4

Transfer the mixture to one of the soda bottles and allow to settle. Screw the lid onto the soda bottle tightly and let the bottle sit for 24 hours.

Step 5

Prepare your wash bottles while the mixture settles. Take two of the soda bottles and pierce a small hole that is about 2 mm in size in the bottom corner of each. Cover the hole with duct tape.

Step 6

Carefully pour the top layer of glycerin into one of the empty soda bottles. Be sure to pour slowly so the biodiesel and glycerine do not mix again. If they do, allow the mixture to sit again until the layers separate once more.

Step 7

Add the biodiesel and 150 ml of water into one of the wash bottles, cap it tightly, lay the bottle on its side, and roll it on a flat surface. You will need to roll the bottle until the water and the biodiesel are completely mixed. Stand the bottle up when finished and then let it settle for three hours.

Step 8

Remove the tape from the wash bottle and allow the water to drain. Replace the duct tape when only the biodiesel remains in the bottle.

Step 9

Repeat Steps 6 and 7, alternating wash bottles until you have washed the biodiesel four times. Make sure to clean the wash bottle before using it again.

Allow the biodiesel to dry in an open soda bottle. When the biodiesel is dry, it will appear translucent. This can take as many as five days. Once it's dry, it's ready to be used.


  • • If during step 6, your biodiesel does not separate from the water after the time window has elapsed, you will need to begin the process again, being more careful about the measurements of the methanol and the lye.
  • • Your soybean oil must be fresh as you begin working with biodiesel. As you have more experience, you may find that you are able to switch to used oil instead.
  • • The amount of ingredients above will give you a small amount of biodiesel. Its purpose is to learn the procedure. Once you have successfully completed it a few times, you can increase the size of your batches.
  • • Methanol, KOH lye, and the HDPE #2 container are all available from online chemical supply stores. Both chemicals should be kept out of the air as much as possible. Soybean oil is also available in bulk once you are ready to begin producing larger batches of biodiesel.


  • • Safety goggles and rubber gloves should be worn throughout every step of this process. Lye can burn the skin. Be very careful to protect your arms, hands and chest when measuring lye
  • • Methanol fumes can be very dangerous. Be sure to work with the raw material in a well-ventilated area. Be sure to read all warning labels on the bottle.

Items you will need

  • 200 ml of 99 percent pure methanol
  • 2 Funnels
  • ½ liter HDPE #2 plastic container
  • 5.3 g of KOH lye, measured into a plastic baggie and sealed until ready to use
  • Stove or hotplate
  • 1 liter of fresh soybean oil
  • Thermometer
  • Blender
  • 4 empty 2 liter soda bottles
  • Box cutter or other blade
  • Duct tape

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