crystalXclear
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bio ethanol instead of ethanol???????
Hello, I have been looking around, but can't see that anyone is useing cheap as chips bio ethanol, to replace the expencive ethanol from chem
suppliers, is there a reason why???? thanx Xtal clear
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ScienceSquirrel
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Ethanol from chemical suppliers is cheap if you can avoid paying the duty to the government because the alcohol is denatured ( rendered unfit for
drinking eg surgical spirit and methylated spirits) or you qualify as an exempt institution eg a university in the UK.
You can clean up methylated spirits quite easily, it is illegal but I doubt you would get caught.
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DJF90
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I don't think cleaning up methylated spirits is easy to be honest. Although it can be distilled from the purple dye, there is an odourous component
that comes over also. Adding conc. HCl (expecting the odour was due to pyridine) does not help. Neither does treatment with base. Shaking with
activated carbon might offer a quick and crude cleanup, but use pellets and not powder, otherwise you'll have to wait an age to decant/filter the
supernatant off.
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mr.crow
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I have some ethanol from the drug store that contains camphor amongst other things. Could this be your odorous component? Haven't tried reacting with
NaOH and distilling it yet.
Double, double toil and trouble; Fire burn, and caldron bubble
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ScienceSquirrel
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I have done a reasonable clean up in the past by adding a few ml per 100ml of of 50% sulphuric acid, at this point the pyridine smell disappears and
the solution becomes opalescent as the petroleum ether separates out.
I then fractionally distilled it and added some sodium bicarbonate and a few grams of active charcoal.
Filtration and redistilation yielded a clear spirit that smelt reasonable, I would not have drunk it but it was OK as 90+% alcohol.
I can buy 95% alcohol but it is around £6 for 250ml so I save it for best :-)
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DJF90
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Thanks for the procedure ScienceSquirrel. Definately sounds better than the one I mentioned! When you say the pet ether separates out, did you
separate the phases prior to fractional distillation?
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crystalXclear
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high, thanxfor all thje info on meths, denatured and such, but the question of bio ethanol sill remains unanswered. can it be used as a direct
replacement? or are there problems with it? Xtal
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ScienceSquirrel
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The charcoal absorbs the pet ether and the purple dye as well.
The pet ether does not form a phase, it separates out as very fine droplets in the acid ethanol mixture.
There is not much pet ether in there, it is really a case of reading the recipe and working out a way to clean it up.
The complete recipe for UK methylated spirits is as follows;
Completely denatured alcohol must be made in accordance with the following formulation: with every 90 parts by volume of alcohol mix 9.5 parts by
volume of wood naphtha or a substitute for wood naphtha and 0.5 parts by volume of crude pyridine, and to the resulting mixture add mineral naphtha
(petroleum oil) in the proportion of 3.75 litres to every 1000 litres of the mixture and synthetic organic dyestuff (methyl violet) in the proportion
of 1.5 grams to every 1000 litres of the mixture.
In practice, synthetic methanol and pyridine is used.
You can use bioethanol instead of commercial spirits, but you need a fairly big still and it will take quite a bit of work.
[Edited on 8-4-2011 by ScienceSquirrel]
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DJF90
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I've posted the same composition here on this site several times before. I know the activated carbon removed the dye but I was unaware of its effect
on the pet ether. Thanks for this.
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