Foreshots

zenbushido · Post by **zenbushido** » Tue Mar 21, 2006 9:12 am

Hi everybody. Is there anybody who know what's the exact composition (coumponds) of foreshots and heads of distillation?

Thanks[/b]

Bujapat · Post by **Bujapat** » Tue Mar 21, 2006 9:45 am

Found that in a Mike Nixon's article (this is a small part of it):
I don't remember where I found this PDF file, surely on homedistiller.org, in the ressources menu...

About heads... and tails.
The problem with both is that if used to distill ethanol then you also end up with all the other undesirable products - the congeners. Congeners is a term used to indicate a 'family', in this case the family of alcohols that are produced when you ferment sugars to produce ethanol. The lightest of these is Methanol, which because it has the lowest vapour pressure comes through almost in its entirety (also known as the 'heads') and the heaviest include goodies such as propyl, butyl, and amyl alcohols. In addition to the congeners, you may also get acetone (ever tried drinking dry-cleaning fluid?) and ethyl acetate which come off with the heads.

It isn't much, it's a begining!

Nichevo · Post by **Nichevo** » Tue Mar 21, 2006 9:55 am

I am not a chemist but AFAIK heads are comprised of mainly ethanol with some methanol, acetone, and the ester ethyl ethanoate(ethyl acetate). The ethyl ethanoate is what is responsible for the rubbing alcohol taste of heads, the methanol should be practically tasteless. Someone posted a nifty link of a chromatography or spectrometry analysis of some booze awhile ago but I couldn't find it.

The Chemist · Post by **The Chemist** » Tue Mar 21, 2006 10:03 am

Some compounds that come out before ethanol on the GC (which is sort of distillation) are methanol, ethyl acetate, ethyl formate, acetaldehyde, acetal and formic acid.

zenbushido · Post by **zenbushido** » Tue Mar 21, 2006 1:53 pm

Thanks for the replies. If it interest anybody, the point of my question is that I wanted to know all the forshots because I want to extract and isolate Methanol from the other foreshots to have pure methanol to make biodiesel. For this I need to know all the boiling points of the compounds of the foreshots.

Post by **Tater** » Tue Mar 21, 2006 1:57 pm

This came off parent sight if its any help The alcohols in the wash begin to vapourise from the wash around specific temperatures. If by themselves they would be ...
Acetone 56.5C (134F)
Methanol (wood alcohol) 64C (147F)
Ethyl acetate 77.1C (171F)
Ethanol 78C (172F)
2-Propanol (rubbing alcohol) 82C (180F)
1-Propanol 97C (207F)
Water 100C (212F)
Butanol 116C (241F)
Amyl alcohol 137.8C (280F)
Furfural 161C (322F)

Once together, a mixture of several of them will be slightly different however. You no longer get them coming off seperately, but always as a mixture. Fortunately for us though, each of the species will tend to dominate around its boiling point temperature, thus we know whats "mostly" coming off at that point. By tracking the temperature of the vapour, you have a fairly good idea when you're collecting the Ethanol your after (78-82 °C), vs when it is starting to get lean and you're into the higher alcohols.

agl · Post by **agl** » Tue Mar 21, 2006 2:36 pm

The quantity of methanol present in the wash will be vanishingly small, parts per million most likely. even if you were able to seperate it fully into pure methanol you would only end up with a tiny ammount probably less than a mL. If you are interested in getting methanol for biodeisel you will need an ammount ~20% of the total volume of biodiesel you want to produce - that would be many L of methanol. If you really want to make the methanol from scratch you could "dry distill" wood - heat some dry wood in a still to 500ºC it will break down into a gas much of which is methanol. (that is why methanol is sometimes referred to as wood alcohol. the afforementioned method is how it was once produced.)

zenbushido · Post by **zenbushido** » Tue Mar 21, 2006 3:12 pm

I have made many research to found to most suitable way to produce methanol at home. Two ways are official methods

1. methanol from the wood. this is the old method to extract methanol. the process is complex , very expensive and you need a LOT of wood to have a fair amount of methanol. This method is not for home scale.

2. methanol from natural gas. This is the modern method , a way more effective than from the wood. But again , it need specialized equipment i can't afford.

I have found another method by deduction witch is more suitable for homescale production.

I will use normal distillation of a wash but , I will make a VERY VERY high level pectin wash. Methanol come form pectin. I have searched the most potent fruits witch have a high pectin level and i will make a wash out of it. to add even more pectin , I will extract liquid pectin from fruits who are not in the wash add it to the wash. I will also add pectin enzymes to broke pectin molecules more effectively.

after that, i will isolate methanol with a compound still.

I'm very excited to see if it will work.

Please reply to tell me what do you think of this method

junkyard dawg · Post by **junkyard dawg** » Tue Mar 21, 2006 4:51 pm

I think there are so many things wrong with that plan its hard to know where to start. Lets just be quick and say that the energy to produce biodiesel with that method will be FAR greater than what you are going to get out of the fuel.

If you just wanna do it to experiment and learn, then go for it. I'm curious about how much methanol you can get from some different washes, but I don't think yer gonna reinvent that wheel.

The Chemist · Post by **The Chemist** » Tue Mar 21, 2006 6:37 pm

What he said. If you want to make biodiesel, do it the way that works best: go to your local McDonald's, tell them you'll get rid of their grease for ten bucks a day, take it home, add sulfuric acid, skim off the top layer and add it to you car. Recycle the sulfuric acid. And be sure your car is diesel.

No, really, you're going to come out much better making ethanol to run your car off than methanol, by fermentation.

furball · Post by **furball** » Tue Mar 21, 2006 7:28 pm

I think the reason that he is going through this loop is that, he is going to use the methanol in the process of transesterfication to convert MickyD oil to biodiesel. I don't think that he is acually going to use the methanol as a fuel its self. It appears that he didn't make clear the process he is going to use and that is the reason for the confusion.
Zenbushido, if you could clarify- are you going to get into trasesterfication of waste oil from the resturants for your biodiesel, or are you going to actually use the methanol as a diesel fuel substitute?

Furball

agl · Post by **agl** » Wed Mar 22, 2006 2:30 am

If you don't get the volume you need you could also look into the ethanol process for biodiesel production. The methanol process is the most commonly used on a small scale, but, you might have another option. I am pretty sure I saw some info on that method on journeytoforever.org but that was a couple of years ago.

zenbushido · Post by **zenbushido** » Wed Mar 22, 2006 12:53 pm

thanks agl , it's a good alternative.