testimento
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Preparation of acetic acid?
Acetic acid is not that available in pure or concentrated form and many topics seem to look for how to make or obtain it. Few methods so far:
1) OTC vinegar. Most are impure and need very energy intensive distillation for purer product. Usually 5-10% concentration. Good for technical
purposes.
2) Vinegar concentration. Several methods have suggested for this. One is to use chloroform or other hydrophobic solvent and salt to drive acetic acid
into solvent phase and then distill off the solvent. Requires lots of expensive solvents.
3) Decomposition of acetate. Metallic acetates tend to form GAA upon pyrolysis. Some, like sodium acetate, may need sodium bisulfate or strong acid.
Laborous, and in case of acid, very expensive, but can produce high quality GAA.
4) Catalytic oxidation of acetaldehyde. This method is documented and working at least to the acetaldehyde phase. Requires somewhat sophisticated
special equipment, but could be used to produce large quantities of high quality GAA. Process essentially contains dehydrogenation of ethanol upon
copper at 300-600C into acetaldehyde, and oxidation of acetaldehyde into acetic acid. This process could probably be done with single catalyst run by
using large excess of oxygen and much longer catalyst time.
5) Acetobacteric oxidation of ethanol. This is technically how we make moonshine, but we let it intentionally spoil with proper bacteria, which will
turn the formed ethanol into acetic acid. Since the bacteria suffocates in it's own excrement in ethanol and acetic acid phases simultaneously, one
would add calcium carbonate into the liquid so the formed acetic acid reacts with it to form acetates and therefore prologing the bacteric life for
quite a lot. In theory this process is mix-n-go, but may encounter some problems, especially with correct bacteria.
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gravityzero
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When I see this type of post I have to ask, where do you live?
Acetic Acid is readily available in the most chemically restrictive environments including the US.
It can be had in concentrated form, from numerous distributors, and on the cheap.
You are on the right path with vinegar, but I find it hard to believe you can find any.
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thebean
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This video as well as this video should be of some use. I haven't tried it myself but it looks pretty simple and straight forward in both videos.
"You need a little bit of insanity to do great things."
-Henry Rollins
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bfesser
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You glossed over what is, in my view, the most important route. In my opinion, all of the other routes you have suggested are a waste of time,
effort, and money.
3.5) NaC<sub>2</sub>H<sub>3</sub>O<sub>2</sub> + H<sub>2</sub>SO<sub>4</sub>. High
purity, high yield, nearly anhydrous, relatively cheap. Anhydrous sodium acetate is mixed with sulfuric acid and ethanoic acid is distilled off at
atmospheric pressure. If only sodium acetate dihydrate is available, it is easily dried.
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Random
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One could probably make strong acetic acid from calcium acetate and sulfuric or phosphoric acid with no distillation.
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S.C. Wack
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It would be hilarious if someone made a gallon of pure acetaldehyde from alcohol with chromate, and then oxidized that further.
Other obviousness: ethyl acetate and the bonus ethanol.
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testimento
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The method for acetaldehyde is presented in germanic forum and it allows one to produce high quality acetaldehyde from ethanol via catalytic
dehydration. Industry used acetaldehyde to produce acetic acid prior the newer processes involving pressures i'm not currently interested in repeating
of. This catalyst is of particular interest because it can be used to produce acetaldehyde, acetic acid, formaldehyde, formic acid and diethyl ether
and probably many more with very minor changes.
Beefie, I actually mentioned indirectly this method in No.3.
These things are not available in my country. Some shops actually sell acetic acid in glacial form, but they only sell very minor amounts like 100ml
for 5 bucks and they aggressively report any larger orders to state forces. Don't ask why. Probably because explosives and drugs. My country hunts
down these two a lot harsher than USSA but because this is a small and remote country nobody knows. Even concentrated sulfuric acid is available OTC
but hey, it costs nearly 100 bucks a liter? I though i'm gonna puke when I actually saw that price tag. I consider everything expensive if they cost
more than few bucks a kg/l except specialty chemicals, but these are just way off scale.
Because of this, and because it's a hobby, I'm interested in making things from dirt. What is the point if you just buy everything from shop and maybe
have to boil something once to get things done? Maybe if you're a cookery but it's not a chem hobby then.. 
[Edited on 22-2-2014 by testimento]
[Edited on 22-2-2014 by testimento]
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subsecret
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Acetic acid is also produced when ethenone (H2C=C=O reacts with water. Vogel's Practical Organic Chemistry outlines a procedure
and an apparatus for the production of ethenone on page 372.
Fear is what you get when caution wasn't enough.
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Oxirane
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Hmm.. What about that acetobacteria? It can be found almost anywhere, like grapes.
If one makes a normal ethanol fermentation process, and when its finished it will have approx 15-17% of ethanol in it. Then there are added a source
of acetobacteria, calcium carbonate equivalent to amount of acetic acid formed, and then air is bubbled with air stones and pump through it? This
produces calcium acetate though.
How about oxidation of acetaldehyde? Acetaldehyde placed into insulated tank with sub-zero water in a flask and air is bubbled through it at specified
rate and this vapor, which is below LEL which is 4% for acetaldehyde, is lead through copper catalysed reactor at 300-400C where it would oxidize into
acetic acid and side products, which are then collected.
[Edited on 7-11-2014 by Oxirane]
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UnintentionalChaos
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Quote: Originally posted by Awesomeness  | | Acetic acid is also produced when ethenone (H2C=C=O reacts with water. Vogel's Practical Organic Chemistry outlines a procedure
and an apparatus for the production of ethenone on page 372. |
Do you have any idea how toxic ketene is? To use it for acetic acid production is beyond inane.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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subsecret
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Well, I don't seem to be dead after testing the apparatus with my nose 
Fear is what you get when caution wasn't enough.
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CuReUS
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how long have you been exposed 
generally ketene ,phosgene have a latency period of 24 hours
read 2nd paragraph under summary
http://www.ncbi.nlm.nih.gov/books/NBK224928/
page 19,lines 32-36
http://books.google.co.in/books?id=DCSuU1yTE1sC&pg=PA30&...
page 193 ,under the title 3.1 Acute toxicity ,sub title inhalation
http://onlinelibrary.wiley.com/doi/10.1002/3527600418.mb4635...
page 5 ,under animal data ,single exposure
they talk about effects 3-14 days later
http://webcache.googleusercontent.com/search?q=cache:nC2hsTe...
in the same page ,on page 4 ,the 6th point -"Effects and mechanism of action" ,subtitle -human data
they say that ketene was a suspect chemical for non hodgkin's lymphoma and other types of cancer
this link might be more helpful than the above
http://books.google.co.in/books?id=y3-Ef3y53PkC&pg=PA420...
[Edited on 8-11-2014 by CuReUS]
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subsecret
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Thanks for the tips. It's been several months since the experiment, and I never had any problems.
Fear is what you get when caution wasn't enough.
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Stupid_Noob
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Distillation of cinnamaldehyde --> benzaldehyde + acetaldehyde...
Ethanol + hydrogen peroxide + Fe(I think) catalyst --> acetaldehyde
And IIRC acetaldehyde (ethanal) can be oxidised to acetic acid, but don't quote me...
[Edited on 11-8-2014 by Stupid_Noob]
Attachment: Acetaldehydefromethanol.pdf (295kB)
This file has been downloaded 700 times
Attachment: ethanoltoacetaldehyde.pdf (37kB)
This file has been downloaded 644 times
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Metacelsus
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| Quote: Originally posted by S.C. Wack | | It would be hilarious if someone made a gallon of pure acetaldehyde from alcohol with chromate, and then oxidized that further.
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Acetaldehyde is much harder to get than ethanol.
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S.C. Wack
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| Quote: Originally posted by S.C. Wack | It would be hilarious if someone made a gallon of pure acetaldehyde from alcohol with chromate, and then oxidized that further.
Other obviousness: ethyl acetate and the bonus ethanol. |
Of all the people who mention acetaldehyde in this thread, you quote me. It is amusing that you feel the need to so inform us, but unfortunately it is
I who must inform you that it appears that you are the sort of person who needs a bright flashing scrolling sarcasm tag...but it wasn't sarcasm,
because it would be hilarious if someone deliberately turned a gallon of carefully and tediously made acetaldehyde to acetic acid...
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Stupid_Noob
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Did any of you know that you can buy glacial acetic acid by the 5 gallon bottle at [\/]enard's?
You can also get 5lb bottles of potassium permanganate. BOTH TOTALLY OTC.
No bullshit.
Oops, I meant 1 gallon bottles of GAA.
[Edited on 11-9-2014 by Stupid_Noob]
...indistinguishable from magic...
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Chemosynthesis
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Yes
| Quote: Originally posted by gravityzero |
Acetic Acid is readily available in the most chemically restrictive environments including the US.
It can be had in concentrated form, from numerous distributors, and on the cheap.
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Stupid_Noob
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I guess I don't understand why anyone would make it... It's only about $30 a bottle... The KmNO4 wasn't much more than that. Why risk time and
effort making something that can be bought cheaper and most likely higher purity.
...indistinguishable from magic...
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Oxirane
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It might not be about that. Acetic acid availability differs strongly on the market cap and conditions where it is used. If it has virtually no
commercial use, it is not available outside chemical companies due to simple fact that nobody buys it. And very few chemcal company sells to
individuals because the work needed is usually larger than the income from that small, even a single-barrel order, which is usually an absurb amount
for 99% of amateur chemists. And since everyone is considered a terrorist nowadays, so be by quest, you'll get more likely a bunch of cops behind your
door than a keg of GAA.
Using ketene for acetic acid production does not sound senseless at all from my point of view - in simplified terms you will only need acetone and
red-hot-heated tube for pyrolysis, and an absorber and there you go. As a bonus you might also get acetic anhydride. It is toxic, hell yeah, but you
will do the reaction in a closed apparatus and use proper exhaust ventilation and PPE. Actually the effort of preparing the setup itself speaks for
larger amounts being produced due to long lead-in time. Same goes for acetaldehyde, formaldehyde and so on: it's just not worth making all that effort
for small quantities, but if you need liters of it, there you go.
[Edited on 9-11-2014 by Oxirane]
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