Biodiesel Reaction Problems

**clackdwack** · 9th May 2007, 09:31 PM

Hi all, im new here to, it seems theres heaps of people going in on the fun of home made gogo juice, anyway i have a problem!!!!!!!..

i did a test batch of 250ml oil (BOILED First), 50ml methonol (acually Metho Spirits 95% Ethonol), 6g Caustic, now after i did the mix, the reaction was that there was no glycarine, but just a thinned out bit of oil, but the previous mix i used 5g Caustic and resulted in a good seperation. Now i thought that the more Caustic you put in the mix, the more Milky it becomes!!!, HELP!!!

thanks mike

**joe** · 9th May 2007, 10:42 PM

Damn... 3/4's way through an email only to have the power flicker for 1 second. Thats Conondale for ya.

Anyhow I'll try to remember where I was...

Your problem are the amounts.

You will need:

1 litre oil- new or used
NaOH (lye/ caustic soda), at least 6g. Used as a drain cleaner and can often be found next to the Drano. (Start with 6 grams)
Methanol at least 250ml.

This is taken from the "World Famous DR Pepper Technique (Pat Pend)" World Famous Dr Pepper Technique (Pat Pend) - Topic Powered by eve community

The quantities are quite important.

Where have you gotten your information from so far.

Let us know how you get on.

**tillyfromparadise** · 9th May 2007, 11:10 PM

Hello Mike

Metho is typically ethanol containing 5% water and will not work in the reaction,
You need methanol.

**joe** · 9th May 2007, 11:29 PM

God how didn't I spot that!?! *joe gives himself a bitchslap*

**clackdwack** · 10th May 2007, 09:44 AM

cool, ok i know the metho contains the 5% water, ill take some pix of the first batch that i made with metho, it worked!!, but the second one is strange. i bought the do it yourself biodiesel book from tasmanenergy,

is there anywhere i can post some pictures????

**TroyH** · 10th May 2007, 12:35 PM

you can host pictures on Image hosting, free photo sharing & video sharing at Photobucket or similar, and then link to them here (using the little symbol that looks like a mountain range with a moon or sun).
I think there is also a biodiesel pictures website, although I dont know the address.

The reaction with ethanol requires a very low amount of water. Theres not much point in boiling your oil if you have that much water in your alcohol

It is also more difficult to dissolve NaOH in ethanol, so generally KOH is used.

Research has shown that in a batch of base catalysed reaction, less than 1% water is required in order to get any kind of decent yield. Even then it may be difficult to get good seperation. I use anhydrous (effectively) ethanol, and seperation is not too bad. Washing is a little more difficult however.

David · 10th May 2007, 01:18 PM

I tried quite a few times to do a reaction with metho and could never get it to work.

**marki** · 10th May 2007, 02:59 PM

Originally Posted by TroyH

I use anhydrous (effectively) ethanol, and seperation is not too bad. Washing is a little more difficult however.

Where do you get your ethanol from?

**TroyH** · 10th May 2007, 03:10 PM

I do my tests as a "research assistant" in a chem lab at my uni. So all of my ethanol is supplied by them, and there is no issues with excise or anything like that. It is undenatured, but I THINK only hospitals, universities and pharmacies (and maybe a few other specialty uses) are able to use 100% undenatured anhydrous ethanol without paying excise. I dry it myself, so that I know it is dry. Later I will be doing determinations to find out exactly how dry it is. I'll be doing this on the oil and also on my ethanol once I've mixed in the KOH also.

Later, when we get to full scale production, I have been looking at fuel ethanol, which is anhydrous ethanol denatured with 1% petrol. The university of Idaho research found no problems associated with reacting when there was 1% petroleum present.