Foo - Calling all science folk! I need some biodiesel assistance

I'm a business kid with some chemistry background so I understand the basics of most of this stuff, but any help from the fine folks of foo would be great.

I just got finished talking to a guy that runs a biodiesel plant. He was looking for some business consulting from the organization I am in. He produces about 1000 gallons of diesel a week and will soon be running 100% on solar energy, which is cool as hell.

Now, one of the by products of creating biodiesel is soap. Through the refining process, about 20% of original crappy oil becomes soap. So, he has a lot of soap on his hands. It's supposedly super concentrated stuff. My question is what would it take to get said "super concentrated soap" into liquid and bar soap form?
He said that liquid soap just required adding water and pretty smell so I guess I am specifically asking how to produce bar soap from the waste of biodiesel production.

Any help is greatly appreciated.

http://www.permaculture.com/node/535

Now, is there any way to make the bar soap without the glycerin?
The glycerin he produces goes back into the production process to remove the methanol from the biodiesel (I think that's how it works). Because he recycles the glycerin he is able to make this system essentially self contained (except for the dirty oil).

Edit: Forgive me if this doesn't make perfect sense.

jsharr: How did you find that article? I want to find more things like that but my google searches are turning up fruitless.

I have no idea. I just found that link via google.

Here is another

http://journeytoforever.org/biodiesel_mike.html

they all seem to mention glycerine as the by product. If he is reusing the glycerine, not sure what is left.

If I'm not mistaken, the lye is the other by product. It seems like the glycerin is the ingredient needed to solidify it.

^^ I think that's right.

Reading through the two links I posted, it appears that lye is added to the vegetable oil and glycerine is a by product. I do not make the stuff. I just did some simple google searches and posted some likely sounding links.

Watch Fight Club. You'll learn how to make soap.

Watch Fight Club. You'll learn how to make soap.

That's what biodiesel guy told us.


Reading through the two links I posted, it appears that lye is added to the vegetable oil and glycerine is a by product. I do not make the stuff. I just did some simple google searches and posted some likely sounding links.

Fair enough. Thanks for the help. Your google search skills are far superior to mine.

Just a comment: My biodiesel-producing friend saves his glycerine and uses it to make fire starters. He runs a vehicle and heats his house with the BD.

I make soap, and there's a confusion going on in this thread between the two main types of soap:

Lye soap & Glycerin soap.

The remainder product of bidiesel(BD) WVO conversion is not pure glycerin. It still contains a fair amount of fats emulsified with the methanol or ethanol used during the initial conversion. This is why it still requires an amount of lye to be added, to finish the saponification process.

An important thing to remember about lye soaps, even those which only contain a small amount of lye, like BD "glycerin" soap: Allow the soap to cure at room temperature for 30 days before using it. Lye (caustic soda) is very dangerous stuff, and you need to be certain of a couple things:
1) You didn't use too much lye in the soap. If you did, then the fats don't inactivate the lye and you end up with a heavy, white residue forming on the outside of your cured soap. The soap can cause chemical burns, especially to the mucus membranes.
2) You allowed the saponification reaction to run to completion. Even if you use the right amount of lye, if you don't let the reaction finish, then the soap will be crumbly or flaky and may have pockets of unreacted lye in it.

True glycerin soaps do not use lye in their production. Glycerin is liquid at room temperature (the BD by-product is not) and has a chemical solidification agent added to it so it stays in brick form. Foaming/lathering in soaps (glycerin and lye based) is controlled by the addition of oils like jojoba, aloe, vitamin E, etc. which aside from foaming, decrease the amount by which soap dries the skin. (In lye soaps, oils are added after saponification).


BTW; Fight Club will not teach you how to make soap. The only important thing you learn is that vinegar neutralizes lye if you spill any on yourself.

He can burn the glycerine to heat the waste oil which is one of the steps of making biodiesel. Also probably one of the most energy intensive steps - heating the oil.

Here's (http://journeytoforever.org/biodiesel_glycerin.html) the journey to forever page on glycerine.

He can burn the glycerine to heat the waste oil which is one of the steps of making biodiesel. Also probably one of the most energy intensive steps - heating the oil.

Here's (http://journeytoforever.org/biodiesel_glycerin.html) the journey to forever page on glycerine.

He runs the facility on solar power so there is no need to burn the glycerin. The glycerin gets recycled back into the process some how. I need to speak to him again.

I know they try and get the methanol out to re-use, but as far as I know, the glycerine isn't normally re-used.

Anyway, they use phosphoric acid to separate the glycerine out, ending up with 90% pure which you can now sell to refineries.

You mix lye (NaOH) or KOH with methanol and then add this to the waste oil, mix vigorously and it will start to separate into biodiesel on top with glycerin on the bottom. You drain off the glycerin and then wash the biodiesel (with water) to clean out the remaining glycerin floating in the biodiesel and other thingies you don't want getting caught in your filters and then voila! Nice clean biodiesel.

I think KOH glycerine will not cause problems if you convert it to soap, but lye based will as was posted above. Also, you can burn the glycerin or use it as fertilizer as well. I've heard about people using it as a food supplement but I'm not sure how safe that really is ...

The methanol/lye mixture binds to the ffa (free fatty acids) in the oil and gets used up in the reaction so that all that is left at the end is biodiesel and glycerin (and the bits of fries you didn't filter out properly before starting). I don't see how you can use the glycerin to get the methanol out. If you put in too much methanol for the mixture, it will separate out as a 3rd layer, but usually you don't end up with that (well not after the first time :P)


Hope this helps ...

Berardino