Why, did yours?

Cheers,

Rich

http://www.boulderbiodiesel.com/biodiesel/index.jsp

[...]

How to make Biodiesel
Making biodiesel is a very simple process. To power our vehicles, we need to reduce the viscosity of
the vegetable oil. Basically the vegetable oil needs to be mixed, given time to settle, then
drained. There are literally millions of different ways this can be done.

Vegetable oil is a tri-glyceride, that’s three vegetable molecules, or esters, attached to one
molecule of glycerin. Glycerin is what makes vegetable oil thick and sticky. To make biodiesel, we
want to remove the glycerin and replace it with an alcohol. This is the process of
transestrification. The alcohol we use is methanol.

To initiate the biodiesel reaction, we need a catalyst. Vegetable oil is an acid, so to ‘break’ the
vegetable oil molecule, we add a strong base. For this we use Sodium Hydroxide (NaOH) also known as
lye. The amount of lye is constant when using new vegetable oil, but used cooking oil varies due to
the amount of Free Fatty Acids (FFAs) from heating the oil. To determine the amount of FFAs, we
perform a titration.

Use Extreme Caution:
Methanol is Flammable and Dissolves Rubber
Lye can Damage Skin, Eyes, and Lungs
Both Can Be Fatal if Swallowed

The Titration
When using virgin oil of any type, the amount of lye used in a biodiesel reaction equals about 1.0%
of the weight of vegetable oil. This amounts to 3.5 grams per liter of vegetable oil. Used cooking
oil, however, is more acidic than new vegetable oil, as heating vegetable oil creates free fatty
acids. Free fatty acids clog your arteries as well as your fuel lines and need to be neutralized in
the biodiesel process. These acids float freely amongst the triglycerides and attach themselves to
anything that is basic, such as lye. So, a titration is performed in order to determine the total
amount of catalyst to be added.

Isopropyl alcohol is used in the titration, rather than methanol, as it will not react with the
vegetable oil. The isopropyl alcohol keeps the vegetable oil in solution.

Careful: it is easy to make a mistake
To avoid errors, perform three titrations, this will help you when making larger batches.
Don’t be stuck with 50 gallons of wasted fuel!

1. Dissolve 1 gram of lye into 1 liter of distilled water
2. Dissolve 1 milliliter of vegetable oil into 10 milliliters of isopropyl alcohol
3. Drop the lye solution into the dilluted vegetable oil while measuring the pH one milliliter at a time
4. When the pH rises to 8 or 9, the free fatty acids have been neutralized

The number of milliliters added to the vegetable oil equals the number of grams of lye per liter of
vegetable oil that need to be added in the biodiesel reaction. This needs to be added to the 3.5
grams per liter required for the reaction. If you added 1.5 milliliters of lye/water solution to
your oil/alcohol in the titration, it would require 5 grams of lye per liter of vegetable used. The
amount will generally vary in between 4.5 to 6.5 grams depending on your source of feedstock.

Making Biodiesel
Biodiesel can be made in a blender, a soda bottle, or a 1,000 gallon mixing tank. The only
difference is the size of the containers and the amount of feedstock used. This section contains the
details on how to make a small batch of biodiesel. When making larger amounts, just use the same
proportions, mixing them in larger containers.

Making biodiesel requires vegetable oil, alcohol and a catalyst. The alcohol can be either ethanol
or methanol; the catalyst can be lye (NaOH) or potassium hydroxide (KOH). When using different
alcohol or catalysts, different proportions need to be added. For simplicity, this section only
contains the amounts for the most commonly available materials: methanol and lye. Mixing methanol
and lye creates sodium methoxide, which is then mixed with the vegetable oil to create biodiesel and
glycerin.

How to make 1 liter of biodiesel
1. Perform a titration to determine the amount of lye needed
2. Dissolve the lye into 200 milliliters of methanol
3. Mix the sodium methoxide with 1 liter of vegetable oil for 20 minutes
4. Allow the glycerin to settle for at least 8 hours. Most of the separation occurs after the first
hour, so you will see immediate progress.
5. Separate the biodiesel from the glycerin
6. Drive!

We hope that you stay involved in the future development of sustainable technology. Please consider
becoming a member of Boulder Biodiesel and join our discussion forum. We often have vehicles for
sale, can help you with vehicle conversions, fuel making, and presentations. Help us convert every
diesel vehicle to Biodiesel!

 Do you have a cite for us showing this box works, or are you wasting our
time?