The biodiesel myth from awhile was miss-tested, while you can run a diesel engine on just about anything, the first one ran on peanut oil, the biodiesel used in the myth was not biodiesel, it was just old cooking oil, to make it into biodiesel, all of the glyserin must be gotten out and the pH made different. To do this, lye (sodium hydroxide [NaOH]) and racing methanol must be used, the glyserin bonds with the lye, and the racing methanol helps with the pH. Also, diesel engines were never designed to run on diesel, they still aren't, there were designed to run on things like biodeisel, and peanut oil, unused though.

this sounds very intresting. has it been disproven yet? I think that i should be tested.

they never mentioned biodiesel on the show. the myth they were testing was if a diesel engine could be made to run on waste vegetable oil, which is exactly what they proved.
vegetable oils are triglycerides.biodiesel is an ester produced by combining the fatty acids on veg. oil with the alcohol, which can be either methanol (methyl ester biodiesel) or ethanol (ethyl ester biodiesel), which also causes the separation of the glycerol (glycerine).
the lye is only used as a catalyst for the reaction, and it does not combine with the biodiesel.
if you want to learn more about biodiesel, and other biofuels, go to:

http://journeytoforever.org

i agree with bernysback

I never said that the lye combines with the biodiesel, I said that it combines with the glycerin. To make sure that this error doesn't occur again, I add this piece of information, the glycerin is then strained off. And I do believe that in that episode, the narrator said something about biodiesel.

but you did say that methanol was used to "help with the pH", which is not the case.

[quote]And I do believe that in that episode, the narrator said something about biodiesel.[/quote]

then you should watch it again.

Very well, I am willing to admit that i may have been mistaken, but I know that methanol and lye are used in titration, which is the process by which the solution is made to be a neutral pH (pH=7), this is evident when an indicator solution( this is pure chemistry, not biodiesel) indicates a slightly basic pH.

this is the titration method used for biodiesel production, as per the website i suggested earlier:

Basic titration
For processing used oil, it's essential to titrate the oil to determine the Free Fatty Acid (FFA) content and calculate how much extra lye will be required to neutralise it.

An electronic pH meter is best, but you can also use phenolphthalein solution (from a chemicals supplier).

Dissolve 1 gram of pure sodium hydroxide lye (NaOH) in 1 litre of distilled or de-ionized water (0.1% w/v lye solution) (weight to volume).

In a smaller beaker, dissolve 1 ml of dewatered WVO oil in 10 ml of pure isopropyl alcohol. Warm the beaker gently by standing it in some hot water, stir until all the oil dissolves in the alcohol and the mixture turns clear. If you're using phenolphthalein, add 2 drops of phenolphthalein solution.

Using a graduated syringe, add the 0.1% lye solution drop by drop to the oil-alcohol-phenolphthalein solution, stirring all the time. It might turn a bit cloudy, keep stirring. Keep on carefully adding the lye solution until the solution stays pink (actually magenta) for 15 seconds.

Take the number of millilitres of 0.1% lye solution you used and add 3.5 (the basic amount of lye needed for fresh oil). This is the number of grams of lye you'll need per litre of oil.

With a pH meter or test strips, use the same procedure without adding the phenolphthalein. Add the 0.1% lye solution drop by drop as before until the pH reaches 8.5.

Potassium hydroxide (KOH) can also be used for titration, see Using KOH, above.

Why?

If a diesel engine runs directly on vegatable oil, why turn it into biodiesel? What advantage is there from the extra processing?