How toxic is biodiesel/glycerine when made?

[gwalker Senior Member Find all posts View Profile Close gwalker]

I understand that the methonal, KOH and their mix, are a very bad substitute for tomato sauce on a hamburger, but after the biodiesel and glycerine are made, are they any less toxic to humans, animals, plants and the environment?

George

[Captain Echidna Senior Member Find all posts View Profile Close Captain Echidna]

Re: How toxic is biodiesel/glycerine when made?

Under making biodiesel there is a thread "what happens if you drink the stuff".

Basically although everything starts of nasty, the idea is it all reacts with each other, leaving chemicals that wont turn the fats in your skin to soap or dissolve your eyeballs.

the biodiesel winds ups up being similar nastyness to the oil it was made from, and the glycerine can be used as fertiliser/ compost.

Of course you could use SVO if like me, I failed chemistry at schoolmconsistently, and was better at tech, but it has its own problems.

[Matt Senior Member Find all posts View Profile Close Matt]

Re: How toxic is biodiesel/glycerine when made?

Biodiesel itself is less toxic than table salt and can be drunk if you feel like it. There is a level that it becomes toxic so be warned. The glycerine itself is full of methanol before its either distilled off or evaporated out. I would not recommend drinking this before the methanol goes out as its quite toxic. You can read up on this elsewhere search on "MSDS Methanol".

Then the glycerine is quite sweet but the alkalininty of it is qute nasty as there are soaps made from your favourite catalyst (NaOH or KOH) and I suppose some left over catalyst too if its not all made into soap.

So there you have it. Its a lot less nasty after being made apart form the methanol but recover that and you away.

Be warned about composting the glycerine, sure it goes well but the concentration of KOH (preferably not NaOH as its toxic to plants) gets too high and will kill things anyway. Just ask my nut tree.

Matt

[RODEONICK Too Busy To Bio. Find all posts View Profile Close RODEONICK]

Re: How toxic is biodiesel/glycerine when made?

Biodiesel itself is less toxic than table salt and can be drunk if you feel like it.

i would like to add a disclaimer to this:

If drunk try to avoid burping or farting as you may prove to start dieseling....

anyone care to admit tasting it??? how is it??
Never tried myself I guess it's because its the first fuel i have ever brought a pump for. Ie no siphon

[pangit Moderator Find all posts View Profile Close pangit]

Re: How toxic is biodiesel/glycerine when made?

I've not tried drinking it myself, but there's a Youtube video kicking around with Daryl Hannah (who is a biodiesel evangelist) drinking some.

Ah yes, here it is:
[youtube]TKyprtCRiGE[/youtube]

[Fitian Was here Find all posts View Profile Close Fitian]

Re: How toxic is biodiesel/glycerine when made?

anyone care to admit tasting it??? how is it?

While converting over 16 vehicles I often had to help prime the system by sucking on the fuel hose on the filter out let. I tasted biodiesel many times - It does not taste as bad as dino diesel and I did not get high or feel sick after. I do not recommend drinking it of course.

Cheers

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: How toxic is biodiesel/glycerine when made?

While the toxicity of biodiesel has been discussed above, there has not been any discussion of the toxicity of the biodiesel by-product.

I believe that the by-product contains:
Glycerol - A sweet substance which, while being an alcohol, is not an intoxicant like the smaller alcohols like Methanol and Ethanol.
Soaps - The neutralisation of the Free Fatty Acids in the oil forms soap from the caustic and FFA. Soaps can burn the gullet and stomach if ingested.
Solid contaminants - burnt foodstuffs, and dehydrated foodstuffs while not at all toxic are unpalatable.
Methanol - Methanol is toxic and there is a significant amount in the by-product layer. In humans, this can cause blindness and death.

As a rough guide, if 20% methanol is used in the process, the by-product from processing 200 litres of biodiesel will be around 40 litres.

• Approximately 40 - 50% of this will be methanol (16 - 20 litres of methanol).
• Approximately 40 - 50% of this will be glycerol and
• Approximately 1 - 15% of this will be soaps and solid contaminants.

[yorta2 Senior Member Find all posts View Profile Close yorta2]

Re: How toxic is biodiesel/glycerine when made?

Tony, I don't fully buy that. I often boil my by-product to vent off the methanol, prior to making soap. I definitely do not lose 40 -50% of the material, in fact the loss is barely noticeable. I think most of the methanol is converted in the biodiesel-making process, and only a small percentage remains in the by-product. But I am no chemist...

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: How toxic is biodiesel/glycerine when made?

Yorta2,
What ratio of oil to methanol do you use? Is your processor sealed to prevent methanol loss?
Methanol to 11% of the volume of oil is used as part of the biodiesel. The remainder is either evaporated, stays in the biodiesel or remains in the by-product layer. If you use 15% methanol, then you would only have a max of 4% remaining in the biodiesel and byproduct. (eg 30 litres Methanol in 200 oil - 22 litres used in process, 8 litres remain in the by-product and biodiesel, or is evaporated off)

A friend of mine tested his fresh biodiesel and only lost about 0.5% of it's volume when bubble dried to remove any remaining methanol, so I presumed that would be typical. Perhaps this is not the case for all biodiesel? If soaps are high, methanol can be combined with soaps (keeping them in solution), until the methanol is evaporated off.

I used simple maths to work it out. I frequently make simple mathmatical errors. If you find them, please advise so that I can correct the errors.

Please advise what amount of methanol you use in the reaction, the volume you lose by drying the biodiesel and the volume you lose by drying the by-product.

[yorta2 Senior Member Find all posts View Profile Close yorta2]

Re: How toxic is biodiesel/glycerine when made?

Tony, I use 20% methanol in my reaction (100 litres of ricebran oil, 20 litres of methanol, and NaOh for the methoxide mixing), water wash the fuel after draining my by-product. I air dry the fuel, but of course that has nothing to do with the by-product. The glycerol mixture is poured into drums and when I require some to make soap, I scoop it out of the drums, heat it to liquify it, measure off 5 litres, and boil it to evaporate the methanol. As I said, very little is lost - I don't need to measure it, as it is pretty insignificant. Of the 5 litres that I boil, I still have pretty near to 5 litres left afterwards with which to make my lye soap.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: How toxic is biodiesel/glycerine when made?

Is it stored in air tight drums?
Is your processor sealed to minimise loss during processing?

the stoichometric(sp) ratio for triglycerides is around 11%, dependant on the type of oil. The shorter length triglycerides like palmate and stearate require more % methanol than the longer chain triglycerides like oleate, linoleate, etc.
As you are using rice bran oil, I doubt that you would require any more than 11% methanol.

Where is your methanol going??

[yorta2 Senior Member Find all posts View Profile Close yorta2]

Re: How toxic is biodiesel/glycerine when made?

Tony, I store my fuel in airtight drums, and the by-product generally is, but not always. My processing reactor vessel has a vent on top (an old tyre valve with the core removed). I find that is enough to prevent pressure buildup - it hisses when I add the methoxide, and I do this while the oil is pump mixing, but just slightly vents during the remaining mixing period. I don't know where any excess methanol goes...

[High Compression II Junior Member Find all posts View Profile Close High Compression II]

Re: How toxic is biodiesel/glycerine when made?

When distilling off the meth from 500 litres of glyc. by-product I used to get around 180-250 litres methanol back....

I used 20-25% meth/vol oil (difficult to measure accurately with that set-up)

What I noticed was that you need to get the by-product to above 80 deg.C before much in the way of meth came off.....

I used to stop distillation at 90 degrees....


Hi Tony! How you doing!..OK I hope-Long time no see....

[yorta2 Senior Member Find all posts View Profile Close yorta2]

Re: How toxic is biodiesel/glycerine when made?

Hmm, I heat my byproduct to around 160-170 degrees F (which is below 80 degrees C) and stir it for about 10 minutes to vent off the methanol - perhaps I need to go higher. I thought that would be high enough.