Sciencemadness Discussion Board - making anhydrous ethanol from vodka.

making anhydrous ethanol from vodka.

Ashot - 22-8-2016 at 15:51

https://www.youtube.com/watch?v=PPm8XPguJ-4

In this video, I am making anhydrous ethanol from vodka. To achieve 99.9% purity of ethanol I have to perform two processes.
1. Fractional distillation to purify ethanol to 95.5% concentration.
This is maximum possible purity can be achieved by distillation.
2. Further purification will be achieved by molecular sieves.
they have pores which are big enough to absorb small molecules like water, but not big organic molecules like ethanol.

Anhydrous ethanol I will need for the synthesis of ethyl acetate by Fischer Esterification process.

Thanks for watching

RocksInHead - 22-8-2016 at 17:30

Nice video! It might be an actual cost effective method, considering a liter of less expensive stuff is only around 10-15$ a bottle.

Ashot - 22-8-2016 at 17:53

Hi, thank you for a pleasant feedback. I believe it is relatively efficient to some other methods. However, my first plan was to extract ethanol from cheap cooking wine that cost around 7$ and provides as much ethanol as 1 liter of 37.5% vodka. Unfortunately, my local store was out of stock so I decided to buy vodka instead of wine.
Also, the most cost efficient method is fermentation of sugar (standard sugar works great but makes ethanol taste and smell unpleasant). Using 4 kg of sugar and turbo yeast I managed to obtain just over 1.5l of pure ethanol in one week. The total cost of ingredients was around 5$.

Arg0nAddict - 23-8-2016 at 00:21

Oh wow I didn't know that not everyone knew this.... everclear is 190 proof [95%] and cost about $17 to $22 a gallon that's my source and you have to ask for it I've never seen it displayed. I don't know if it's thay way in every state but west coast yes.

But you can break the azeotrope during distillation well more correctly an extractive distillation. Let me try to explain at the top of the first column the azeotropic ethanol then condenses and falls down a second column where it meets a third solvent in liquid phase which will form two layers like Benzene or toluene which will chemical remove the azeotrope.

Now distilling or decanting you're still gonna have some nasty left so I give that a guess of 99%

I dry mine like you do but I'm not sure I'd call it 99.9 it always gets a little haze from stuff the 3a's introduce.

Edit: you may be in another country but to the USA people

[Edited on 23-8-2016 by Arg0nAddict]

zed - 25-8-2016 at 16:15

Liter! Everclear might cost $17 per liter. The federal and state beverage alcohol tax, limits how cheaply Everclear can be sold.

Everclear Alcohol - 1.75 L
0632H | 190.00-proof
$36.95 $36.95

I swiped this off of a website.

"Everclear" is actually a brand name. Brand x, might be somewhat cheaper.

OK, I searched, my latest research suggests 190 proof, costs about $20 dollars a liter.

[Edited on 26-8-2016 by zed]

[Edited on 26-8-2016 by zed]

[Edited on 26-8-2016 by zed]

Ashot - 26-8-2016 at 03:06

I believe it is possible to find ethyl alcohol that's made for other than drinking purposes. However, it is usually denatured with methanol and bittering agents.
I will need ethanol for the synthesis of ethyl acetate and then I will be using ethyl acetate for the decaffeination of raw coffee beans. I believe for this processes ethanol must not be contaminated with methanol and other unknown compounds.

Morgan - 30-4-2017 at 19:57

An odd thing as I was perusing a military base liquor store here in Florida where they only sell 151 Everclear and not the 190 proof. Several states limit alcohol content to 151 and Florida is one of them. Anyway after looking at all the unusual, creatively shaped bottles in this somewhat vast store I glanced at the Everclear and they had both proofs. I opted to buy a cheaper "Clear Spring" 190 proof brand at $12.99 for 750 ml and no tax. I had only gone in to buy some beer.
And in my town they don't sell liquor on Sunday until after 1PM. But on base this place opens at 8 AM which is a pretty early start. So I count two circumventions or rather some animals or more equal than others.
In the past, I "had to" order a 190 proof bottle out-of-state via mail which is legal but you pay a tax and shipping - because I thought the law is the law so to speak.

PirateDocBrown - 1-5-2017 at 12:50

I use sieves for the final dehydration and for storage.

I distill over NaOH to a concentration above the azeotrope, then use K2CO3 to salt out most of the remaining water. Then the sieves.

ave369 - 2-5-2017 at 09:16

In my country, Bryntsalov medical antiseptic alcohol is available. It's like Everclear, but of somewhat lesser grade (but still potable). A five liter jerrycan of the stuff costs $25 and it's pretty much azeotropic. I use this ethanol in my lab.

AJKOER - 7-5-2017 at 05:09

Always with the boiling!

In a loosely covered (as O2 can also function as an electrode in a metal-air battery here) ethanol/water mix with Aluminum, plus a catalyst (Hg or AlCl3..), may form the alcoholate! See https://chemistry.stackexchange.com/questions/44680/is-there... .

Caution: Hydrogen gas evolution which can form explosive mixtures with air! So, perform outdoors. Also, read the MSDS on any possible alcoholate formed given reports of combustion of the dry salt with moist air (note, you may be working with an Al alloy). Also, my prior research on magnesium ethylate from a manufacturer revealed that it is actually sold as a crystal salt composed of an adduct of magnesium ethylate and ethanol, likely to mitigate safety concerns on shipping.

Any formed aluminum alcoholate will react with any present H2O/moisture to create Al(OH)3/Al2O3, releasing the respective alcohol, which may burst into flames per reports with some of the metal alcoholates.

If using Al foil (which is usually an alloy), pass over a flame to remove any protective coatings.

If the goal is to remove water, the Aluminum should be not much more in moles than 1/3 of the moles of water present.

Have yet to perform this experiment myself sucessfully without an appropriate catalyst.
-------------------------------------------------

A variation of this experiment would be to perform a low voltage electrolysis of an ethanol/water mix with Aluminum electrodes (see http://pubs.acs.org/doi/abs/10.1021/ja01498a024?journalCode=...), and some NaI (iodide is a possible source of solvated eelectrons) to serve as an electrolyte. The cited reference electrolysis is quite interesting for a couple of reasons. First, is the claimed possible transient formation of lower valent states, including Al+ for Aluminum (also, with Magnesium, Mg+). Next, given that the medium (pyridine related to benzene together with ethanol) with additives is somewhat permissive to the presence of solvated electrons, the latter, in my opinion, could account for the over 100% H2 yield and the degradation of the solvent and other compounds present as:

e(aq) + e(aq) (+H2O) --> H2 + 2OH- (fast reaction, k=7.26×E10)
-----------------------------------------------------------------

An interesting thought is that working with alcoholates which form stable adducts with there respective alcohols only, may be a path to separating different metal alcoholates (and the corresponding regenerated alcohol with the addition of water) via fractional crystallization.
---------------------------------------------------

[Edited on 7-5-2017 by AJKOER]

[Edited on 7-5-2017 by AJKOER]

Sulaiman - 7-5-2017 at 06:58

I am presently on my third fermentation-distillation run,
c17g sugar per litre per %ABV, I think c16% is a reliable target.
First simple distilation gives 40 - 60 %ABV, second gives 70 - 90 %ABV, depending on how you collect the distillate, i.e. not too greedy

Should be straightforward to get near azeotropic using fractional distillation, but so far I've failed

90% easy, 95% do-able, azeotropic has eluded me so far.
(academic challenge, not economically viable)
Heat, sugar, yeast, nutrients, water, time ... very cheap.
and the fermentation process is fascinating to me,
plus it is a nice reagent to synthesize as it can be made with wild ingredients.
(the 'down' side is that I doubt there is much for me to discover after >7,000 years of continuous 'research'

Fermenting sucrose quickly does gave me nasty smelling byproducts and cloudy 'tails',
my present batch has been slowly fermenting <= 15^oC and is near completion (s.g. 1.00 to 1.01 at the moment) and has far less, but still some, 'nasty' smells.
(reportedly esters, which I've not yet isolated - and I'm not ready to analyze yet,
and judging by smell and pH, quite a lot of acetic acid)
I have a non-muslim friend that does occasional taste-tests for me ...
- apparently the bouquet and pallete vary from metyhlated-spirits to paint-stripper

P.S. includes a free CO₂ generator.

[Edited on 7-5-2017 by Sulaiman]

macckone - 7-5-2017 at 08:16

Ah the joys of fermentation.
Simply adding sugar and yeast is less effective than
adding a nutrient with the above two items.
'Turbo yeast' contains the nutrient and yeast in one
mix. To get better alcohol 'for medicinal purposes'
you want to use a lower sugar content and a slower
fermentation. Specifically regular fleschman's yeast
as sold in the US is surprisingly good but dies at
a relatively low alcohol content and does not contain
the nutrients needed.

For making fuel grade, use the fastest and highest
alcohol content yeast you can find. It will produce
very little methanol but a lot of heavier alcohols and
other compounds that are relatively easy to distill out.

Letting the rum wash sit will result in the acetic acid
and ethanol combining to form ethyl acetate which
gives a pleasant butter flavor once distilled. Ethyl acetate
and ethanol are next to impossible to separate without
chemical means, adding sodium hydroxide being the
usual method. That will also release other things
so it can only be done after double distillation to
remove other esters with higher boiling points.

The inital wash must be acidic or amines are carried
over and that is always bad.

Then a final distillation will be mostly ester and higher
alcohol free.

<end exposition>

tsathoggua1 - 10-5-2017 at 07:46

To get the last traces of H2O out of EtOH there are a few options.

Vacuum distillation should break the azeotrope,
Storage over and then distilation froom CaO,
And for final chemical dessication, assuming its an alcohol sans any functional groups which would react with it, or the decomposition products, reflux over then distillation from calcium carbide. The result is decomposition of the carbide, giving off acetylene (caution-highly flammable, to not allow it to become pressurized, as acetylene cylinders as sold commercially contain the gas as a solution in eiither acetone, or, IIRC, sometimes DMF soaked into a porous, absorbtion substrate since otherwise, pure, unadulterated liquid acetylene has a tendency to explode. )

AJKOER - 8-9-2018 at 06:54

An interesting experiment (not requiring CaC2) would be to add a tiny amount of Zinc metal to a heated mix of ethanol-water, as a possible way to chemically remove small amounts of residual water.

My rough estimate on some of the chemistry involved:

Zn + 2 H2O (l) --> Zn(OH)2 (s) + H2 (g)

Zn(OH)2 + mild heat --> ZnO + H2O

ZnO + C2H5OH --> Zn(OH)2 + C2H4 (see https://chemistry.stackexchange.com/questions/47894/zinc-oxi...)

From an electrochemical/radical perspective:

H2O = H+ + OH-

Zn + 2 OH- --> Zn(OH)2 + 2 e-

e- + H+ = .H

.H + .H = H2

.H + C2H5OH --> .C2H5O + H2

.H + .C2H5O = C2H5OH

......more products

Now, one could try Mg or Fe in place of Zn, but magnesium (as could be zinc) may be too anodic (being highly ranked in an anodic index, see for example, https://www.zygology.com/cms/upload_area/pdf/Zyg-Anodic-Inde...), and as such, could result in more breakdown of the C2H5OH itself. Per a dated source (https://books.google.com/books?id=jvjmAAAAMAAJ&pg=RA1-PA... ) Mg is apparently more reactive in alcohol than pure water, to quote:

"So, for instance, the alcoholic solution is acted upon more vigorously than pure water"

The implication of the above is when it gets down to small residual amounts of water, perhaps trying to convert the H2O to hydrogen may prove to be effective, but likely at the expense of purity of the ethanol which could be contaminated with breakdown products.

[Edited on 8-9-2018 by AJKOER]

unionised - 8-9-2018 at 07:13

What source is best depends where you are in the world.
https://www.diy.com/departments/la-hacienda-bio-ethanol-fuel...
Contains a bit of MEK which could be removed by distillation.

Tsjerk - 8-9-2018 at 08:14

In the Netherlands spiritus is sold in any supermarket which is a smelly blue 85% ethanol mixture containing methanol, blue dye, pyridine and denatonium benzoate. It is perfect though when a bit of methanol is no problem.

About 1 ml of sulfuric acid per liter of spiritus protonates both the pyridine and the blue dye, preventing them from coming over in a simple distillation. The stuff is so cheap (2 euro/l) you can easily discard the first 30% as the methanol containing fraction when a column is used.

Clear 96% ethanol comes over afterwards, reflux with CaO and store over sieves.

nimgoldman - 8-9-2018 at 08:31

Since ethanol over 40% is regulated and not available in my country (only for licensed businesses), I make my own. It is actually quite simple (after several trials).

It takes about 10.5 kg of sugar (approx. $6.50) and turbo yeast ($10.00). I use 30L plastic bucket and make the mix of sugar, yeast, activated charcoal and yeast nutrient as per instruction (the Alcotec brand comes with all this).

Then I leave it to ferment for about 9 days with a bubbler - when fermentation stops, the yeast will fall down and the solution clears. Then I siphon off most of the liquid, I don't bother with filtering the sludge on bottom.

Then I distill it using a 30L canning pot with a hole in the lid where I put 60 cm Vigreux column. The resulting alcohol is 70-80%.

Then I re-distill it to 90%.

Then I mix it with activated charcoal in beaker and stir fo abour 10 minutes and then vacuum filter through a bed of Celite. This removes the smells.

Then I re-distill it to 94%.

Then I add molecular sieves, leave for couple of days, just enough to get over 95%, filter and vacuum distill the product (just to separate the ethanol from the sieves' dust).

Then I dilute to 95% if needed (I don't need anhydrous if I do, then use more sieves and resort to chemical drying methods - never tried zinc but will try magnesium).

I keep the waste alcohol, which is still around 40% so when enough is collected I use it for next run.

I usually make about 1.6 L of 98-99% ethanol in one run.

Unfortunately I am not able to get 95% in just two distillations even with the 60 cm column. The heating mantle and the distillation head thermometers are off by a degree or so, hence precise control is not possible.

[Edited on 8-9-2018 by nimgoldman]

[Edited on 8-9-2018 by nimgoldman]

S.C. Wack - 8-9-2018 at 08:43

Quote: Originally posted by unionised

What source is best depends where you are in the world.
https://www.diy.com/departments/la-hacienda-bio-ethanol-fuel...
Contains a bit of MEK which could be removed by distillation.

After the distillation a test with KOH reflux would be wise...reflux with acid and base takes care of acids, esters, amines, aldehydes...and ketones...without Extreme Fractionation.

BTW vodka in the USA is just watered down corn biofuel that was supposed to be going into everyone's gasoline.

I prefer lime before sieves, and have done turbo and non-turbo, and cheap vodka...it's a lot of time and electricity probably to get from turbo to pureish 40%...I recommend a few quick distillations...so really starting from vodka is not a bad idea.

SWIM - 8-9-2018 at 09:53

Quote: Originally posted by Morgan

An odd thing as I was perusing a military base liquor store here in Florida where they only sell 151 Everclear and not the 190 proof. Several states limit alcohol content to 151 and Florida is one of them. Anyway after looking at all the unusual, creatively shaped bottles in this somewhat vast store I glanced at the Everclear and they had both proofs. I opted to buy a cheaper "Clear Spring" 190 proof brand at $12.99 for 750 ml and no tax. I had only gone in to buy some beer.
And in my town they don't sell liquor on Sunday until after 1PM. But on base this place opens at 8 AM which is a pretty early start. So I count two circumventions or rather some animals or more equal than others.
In the past, I "had to" order a 190 proof bottle out-of-state via mail which is legal but you pay a tax and shipping - because I thought the law is the law so to speak.

That's a result of our federal system. The states have very limited power to control things on a federal installation, especially military bases.

Do they sell to civilians? I always assumed you'd need a PX card; or whatever they call it here in the 21st century.

Maybe it's a smart phone App by now.

Ubya - 8-9-2018 at 12:43

Quote: Originally posted by nimgoldman

Since ethanol over 40% is regulated and not available in my country (only for licensed businesses), I make my own. It is actually quite simple (after several trials).

It takes about 10.5 kg of sugar (approx. $6.50) and turbo yeast ($10.00). I use 30L plastic bucket and make the mix of sugar, yeast, activated charcoal and yeast nutrient as per instruction (the Alcotec brand comes with all this).

I keep the waste alcohol, which is still around 40% so when enough is collected I use it for next run.

I usually make about 1.6 L of 98-99% ethanol in one run.

[Edited on 8-9-2018 by nimgoldman]

[Edited on 8-9-2018 by nimgoldman]

1.6 L from 10kg of sugar???

that's not a good yield at all

Morgan - 8-9-2018 at 16:47

Quote: Originally posted by SWIM

Quote: Originally posted by Morgan

You have to be military or the spouse to shop on base. Sometimes I see retired or higher ranks buying entire shopping carts full of hard liquor and wonder if they are having massive parties or buying for friends. Who drinks that much booze ...

nimgoldman - 9-9-2018 at 13:38

Quote: Originally posted by Ubya

Quote: Originally posted by nimgoldman

1.6 L from 10kg of sugar???

that's not a good yield at all

Well I don't know how to improve it any more. I looked on so many tutorials, even using thermostat-drived heating mantle with a 60 cm Vigreux column but still can get only 3/4 of the liquid at good separation.

Maybe if I reduce the drip rate at absolute minimum it would work, but then the distillation will take over 20 hours and eat many kilograms of ice which is unbearable...

Ubya - 9-9-2018 at 15:28

Quote: Originally posted by nimgoldman

Quote: Originally posted by Ubya

Quote: Originally posted by nimgoldman

1.6 L from 10kg of sugar???

that's not a good yield at all

maybe you can increase the concentration before distillation by salting out the ethanol using sodium chloride (bought as road salt because it's cheaper and maybe at the end let the depleted solution to evaporate to reuse the salt in the next batch), use the highest ethanol tolerant yeast, wait until fermentation stops. maybe try a more efficient column and allow a high reflux to get a better separation. using a water chiller instead of ice could make the process more autonomous