Author Topic: Acetic acid from vinegar... A better method  (Read 7324 times)

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  • Guest
That sucks...
« Reply #20 on: February 16, 2004, 10:34:00 PM »
I remember seeing 10-20% distilled vinegar by the gallon, but the store quit carrying it for some reason.

I could live without an OTC source of acetic acid if I could get OTC source of 30% H2O2. And no, I don't consider wood bleaching kits as an OTC source. Maybe moving to Arizona where all of those rocket guru's live I could find it. I saw a company that sells stills for making 90% H2O2 from 50%. 

I need to dig up that old reference for using fuel cells to produce H2O2.


  • Guest
Separation method of Acetic Acid
« Reply #21 on: February 17, 2004, 02:13:00 AM »
Regarding the method of production of Acetic Acid by salt separating vinegar into Acetic Acid/Isopropanol and Water/Salt layers:
When a large excess (like 300G) of "Rock Salt" (crushed in mortar/pestle) was left in 200ml of 5% clear vinegar and 50ml of Isopropanol overnight in a seperatory funnel, a top layer of roughly 60ml formed, upon collecting this layer (the excess salt stayed in the sep funnel), it was found NOT to react with baking soda.  Upon addition of 1ml of water, it reacted violently with baking soda.
This leads me to believe that this layer contains 0% water, 83.3% isopropanol, 16.6% acetic acid.

If you require pure acetic acid, the difference in boiling points is large enough that simple distillation can remove the isopropanol.

sYnThOmAtIc: 35% H2O2 can be found in some hippy food stores... Also in beauty supply stores...

I vote this the easiest method of production of acetic acid.
Thank you sYnThOmAtIc!


  • Guest
« Reply #22 on: February 17, 2004, 02:52:00 AM »
I appreciate the comment.

Just for clarity
But 3000ml x300ml portions= 10 washings x2min= 20minutes= 300ml an hour or 600ml if you don't wait 2min for each wash or 1200ml if you just wait thirty seconds which is still quite a bit of time. 

Just for clarity, the ammount I'm refering to is the ammount of acid obtained not liquid processed.

All hardware stores and large shopping centers with W-k arts stopped selling the 95% clear H2SO4 in the 2l cream white bottles. I found the conc black crap the other day. I'm unsure of what they use as the dye to indicate spills, but I don't think I would try to use or clean it. This methamphetamine lab shit has made it hard to get common chems OTC.

I though about looking or inquiring about an order of conc H2O2 at a health food store after reading that people add a few drops of it to elixers and other drinks to add oxygen to their body. So I guess I'll start the hunt again.


  • Guest
« Reply #23 on: February 17, 2004, 03:44:00 AM »
"forgodsakes, 80% acetic acid is available at any photographic supply as stop bath (get the ones without indicators)"

This is false.  Not all photo stores are equal, especially in medium-small towns vs. big cities.  Why do you think people would fuck with vinegar if we could go to the photo store?  The closest I could find was 30% with shitloads of other stuff in it.


  • Guest
Not even mail order?
« Reply #24 on: February 17, 2004, 05:43:00 AM »
Same here. I can only get premixed stop bath solutions. It come in two containers and each is contaminated. I would hope anybody that has means would buy it. I can only get it by mail order. When I look at the suppliers list and 40% H2SO4 requires DEA form I don't buy anything. I'd rather screw around with vinegar. Single people need things to keep them busy anyhow  ;D .

Besides even if you can get it and you don't buy any other photo chems but maybe one or two others quite frequenty, you have to worry about how that might look! So it is nice to rotate and enjoy the lower forms of chemical acquisition  ;)


  • Guest
You could destill acetic acid, but you would...
« Reply #25 on: February 17, 2004, 07:52:00 PM »
You could destill acetic acid, but you would need a stronger vinegar than 5%, because there is an azeotrope betwen water and 3% acetic acid. I use 30% vinegar essence and destill trough an vigereux column at a veeeery slow rate.. the destillate came over at 100 C and smells acetic, but fairly as strong as the essence.. After a while the temp will raise and acetic acid will come over, this could then be dried with a proper drying agent..


  • Guest
Another way to GAA
« Reply #26 on: February 17, 2004, 09:37:00 PM »
Admitted, this is not so fast and and easy as the IPA - salting out method or the sodium acetate, but it has some other advantages....

A coppertube of about 70cm length and about 3mm inner diameter is connected to a vessel/flask where acetone is brought into a gaseous state of matter (aka boiling). A batwing propane-burner is installed under the part of the tube at the outlet side which heats the tube to a dull red glow. (The burner is positioned at about 50cm from the tubes inlet). The outlet of the tube leads straight into a big vessel with vinegar. This vessel should be halfway filled with broken glass and be hold at a temperature of about 70°C. The vessel has to be closed except for an outlet connected to an smoothly running aspirator.

The acetone is brought to an straight boil and the tube is purged by the acetone. The burner is started and soon after the tube reached a dull red heat direct over the burners flame ketene will be formed by thermal decomposition of the acetone. The ketene reacts with the acetic acid in the vinegar to form acetic anhydride which reacts with the water to form acetic acid. It is possible to use straight water from start instead of vinegar but this is unfavorable as the reaction of water and ketene is rather slow and ketene would escape. Ketene is poisonous so the aspirator which must run down the drain - no aspirator-station like design here.
After some time you will have a mixture of GAA and acetic anhydride which can be separated by simple distillation. The GAA will be absolute anhydrous. The ridiculous acetic anhydride may be converted to GAA by the addition of water. This should be done ASAP as acetic anhydride is a scheduled compound and might cause legal trouble.

This is a little bit a piggy-setup as the unreacted acetone is washed down the drain and not recovered. But it spares all these washbottles and scrubbers and condensors and stuff, and acetone is asscheap and not regarded enviromental dangerous. (at least the bottles I buy carry no such warning)

Yields: At least 50% from theory, up to 80% with some finetuning.
Ok, it is some work included. But once the work is done you have a neverending source of GAA....


  • Guest
Hell yea!
« Reply #27 on: February 19, 2004, 12:58:00 AM »
Tube furnace is the shit! I used to know of about three or four wonderful thing that could be made with one, but have forgotten them all.. I built a nice tube furnace a while ago and I have three different tubes, copper, glass, and porcelain. The porcelain one has some palladium catalyst packing for some reason  ;)  Only got around to wrapping one with a homemade heating mantle. Shit got expensive once it came time to wrap in wire and glass fiber sheeting.

Thanks for pointing this one out. I didn't know about acetic acid from a tube furnace. Actually, I like it alot.

Oh yea, I think I was going to make benzene or something. And nitrobenzene from that for some oxidation of eugenol. I have decided that is a bit of work for vanillin. There were a whole slew of things I found out about here that I can't remember.


  • Guest
Hey now,
« Reply #28 on: February 20, 2004, 04:45:00 PM »
Hey now,

 HOws it going all?I have a quick question about the shelf life of GAA.Ive had a bottle for probably 4 years is it still good? :P


  • Guest
That's a wonderful procedure Org - thanks.
« Reply #29 on: February 21, 2004, 06:23:00 AM »
That's a wonderful procedure Org - thanks.

I intend to build such a reactor and document it when situations allow.

But as you said it's a "piggy setup"
I plan to make it a bit more elegant.

having an empty flask in an ice-salt bath or similar preceding the acetic acid would do well as an acetone trap, yes?
What I have a question about is this; My uncle buck doesn't have sufficient running water at his lab to run a water aspirator continuously like that.
 I've read hypo's posts about burning the ketene, and frankly I'd rather not purposely introduce fire into the equation.

Ketene is decomposed  by alcohol and ammonia yes? What if one placed a vessel of either between the acetic acid and the vacuum source? Would that be sufficient to be able to use say a rotary vane pump, vented outside of course, or a recirculating aspirator safely?

Another thought that just crossed my mind was placing the whole aspirator station outside and just running a line to the apparatus.

We'll see how it works out I suppose.



  • Guest
« Reply #30 on: February 21, 2004, 09:40:00 PM »
I don't know exactly what it decomposes to, but according to msds "expect co/co2 evolution". I'm assuming that it may decompose slowly into methanol. CH3COOH minus co gives methanol, CH3OH, CH4O? I'dd say that as long as the bottle hasn't exploded yet it should be good for most purposes? If it plays a critical role as a reagent or something you might want to oven dry some glass and distill it, but that may be completely unnessecary..


  • Guest
Other acids to increase ketene absorption
« Reply #31 on: February 22, 2004, 03:19:00 AM »
It is possible to use straight water from start instead of vinegar but this is unfavorable as the reaction of water and ketene is rather slow and ketene would escape

Will H2SO4 assist in the reaction of ketene with H2O or must it be acetic acid?


  • Guest
Why use that when vinegar could be used?
« Reply #32 on: February 22, 2004, 03:41:00 AM »
Why use that when vinegar could be used? Vinegar is easier to get and cheap.

BTW for the ethanol oxidiser.. Why not use chromic acid to make if from ethanol. Easier to get and less suspicion in purchase.


  • Guest
« Reply #33 on: February 22, 2004, 04:25:00 AM »
the black shit works.  add dh2o, mix well, let stand and seperate, blow off excess dh2o.
  ive used the black shit for hcl generation and it works great.  i tried it to convert PI and KI into HI which was subsequently oxidized into I2.  it seemed to work ok but sublime your I2 just to be safe and insure cleanliness


  • Guest
Perhaps the absence of decent vinegar
« Reply #34 on: February 22, 2004, 04:46:00 AM »
to start with is what would drive one to synthesise ketene....
If sulfuric acid will promote the reaction between ketene and water then the acetic acid/anhydride produced would easily distil from this cleanly, that is why I asked. I just wonder about possible reaction with the other gases - CO and ethene.


  • Guest
experiments with alcohol
« Reply #35 on: February 22, 2004, 04:52:00 AM »
we did these oxidations of EtOH in lab class. the products from Cr+6 and KMnO4 are very dependent on amts and conditions, but any acetCHO can be recycled. spose you knew like almost everyone else, but others are watching and a look at the archives show a lot of bees who dont read the books. one thing ive only seen in one book is the dry dist of Cu acetate giving pure GAA, @250 300C.
  the real reason for posting-somewhere in Kirk-Othmer they talk about the acetone/ketene thing. their example reactor gives not only ketene and CH4, but also AcOH, Ac2O, and unreacted acetone. this from the vapor spending 1 sec. in reaction zone. most of the ketene reacted with the AcOH in the hot(150C) condenser, giving Ac2O and AcOH mix. unreacted acetone is dist. off, then whats left is dist. 3X over Ca acetate giving Ac2O and residue of diketene polymer catalyzed by the Ca acetate.
  compare this to the other reports of variable success and products. some tweaking(of the app.) may be necessary. have any bees had the same success as vogel? i'll just stick to the hot acid KMnO4 till someone does.


  • Guest
« Reply #36 on: February 22, 2004, 05:41:00 AM »
You can recover your acetone either by adding another scrubber filled with cold water where you bubble the acetone in AFTER the water/acetic acid. This will hold the acetone back which can bne separated from the water lateron. The further outlet should be directed by an nozzle into the flame of an propane burner - thats the safe way to do this if you cannot run the shit down the drain by an aspirator. Ketene is poisonous - period. After the scrubber there will be only tiny amounts to burn - no real problem.
"Is decomposed by" is a fine sentence - it says nothing about how fast this happens. Mostly this says it happens very, very slow as the fast variation would be "reacts vigorously"
Ketene reacts very slowly with cold water.
Ketene reacts slowly with acetic acid in the cold. (this is not important here as the ketene comes fucking hot outa the tube...)
Acetic anhydride reacts slowly with cold water.

Praesodynium, you may look at Rhodiums page for "ketene" to understand the reaction mechanism. Ever heard of the difference between mineral acids and organic acids?

Turden, so you SERIOUSLY go to build this, PM me.


  • Guest
Org - Wonderful input.
« Reply #37 on: February 22, 2004, 05:50:00 AM »
Org - Wonderful input. thanks

I don't know what you're implying but I plan on starting to assemble parts tomorrow  8)


  • Guest
GAA down under
« Reply #38 on: February 25, 2004, 07:59:00 AM »
Im not sure if anyone can benefit from this info but I'll post it anyway, for reference sake.
Swim, recently paid AUD$69.95 for 2.5Lt AR 98% GAA, from an allied chem supplier. GAA is not rare here, but it is not the easiest to buy..if it werent for an old friend's advice I would be making my own via sodium acetate  :)


  • Guest
Production of acetic acid: This post might be...
« Reply #39 on: April 24, 2004, 09:38:00 PM »
Production of acetic acid:

This post might be of interest for the acetic acid lacking bees:

Post 502712

(Organikum: "Rhodium wrote: Re: If you do not remove the...", Stimulants)

Oxidation of EtOH to acetic acid using ferrous acetate (FeSO4 should work too) and H2O2. It wont get much easier I guess.  ;D