Sciencemadness Discussion Board - Acetic Acid Synth. Easy Home Version.

Acetic Acid Synth. Easy Home Version.

Have2Know - 26-3-2014 at 12:26

Recently I ran into something really annoying....All over eBay was cheap glacial acetic acid, which was teasing me since no one on eBay will ship acetic acid to Hawaii. At first I wondered " conspiracy " . So I tried several home methods, I ended up using my original Ethyl Acetate + NaOH = Sodium Acetate + 80% H2SO4 = Acetic Acid, it always works, and it is predictable as heck. I wanted to see how much sodium acetate I could make this way in one batch, while managing the exothermic reaction as to not boil of my ethyl acetate, or need exotic cooling. 6 moles is the max at once with SS kitchen stuff and ice. I buy the 99% Ethyl Acetate at the hardware store, in 1 gal cans, where it is now sold as MEK Substitute, thus in the effort to make things more healthy, ethyl acetate went OTC.

Simply mix the ethyl acetate with lewis lye in a 1 mole NaOH + 1.1 mole Ethyl Acetate ratio, 1.1 since some is lost to evap. I just zero a kitchen scale to the Wally Mart SS beaker, mix x grams of lye, and x grams of ethyl acetate, and the easy part is done. Now you can take a small break, But do not do what I did, and leave even a "Tiny" 1-2 mole jar in the kitchen with your in laws and forget about it, when I remembered, they had already withdrawn from this kitchen and in the jar my sodium acetate ( mostly) was bone dry, so they must have been treated to my new super strength ethyl acetate / alcohol air freshener!

When you mix it, it just sits there....and does nothing for say about 10 min, then ever so slowly the temp rises and warm spots form, heat of course accelerates the reaction. Then the reaction speeds up big time, and requires cooling. I just use a big stainless steel beaker, with an ice filled bowl on top to act as a reflux condensor. With this plopped into an ice bath and me stirring like mad I can control about 6 moles with confidence. It is funny how the small lye prills morph into larger identical shaped sodium acetate prills, for some reason the starting lye physical state is carried forward and perfectly preserved in the first reaction, they are 3-5 times bigger though.

When the reaction subsides, I seal the Sodium Acetate prills in a jar with a jigger of ethyl acetate, for 24 hr, just to make sure there is no lye left.

For Distilation:

Since we can't get any non added surficant's, chromates, or other added crap added phosphoric acid here, I use 75-80% sulfuric acid, I am always sure to add the acid to the ice water to make 80%. The reason is at 98% sulfuric chars the Sodium Acetate, and gets way to hot. At 80% it still self distills in the beginning, and reacts fast.

Just for reference one 6 mole batch makes about 350 ml glacial acetic acid. I do not know why acetic acid is so hard to find here, all the organic farmers want it so they can spray weeds with 15-20% acetic acid solution, while keeping your organic farm certification. For me the best part is that you can replant / plant seed the next day : )

Last there is a small bonus in this acetic acid workup, the reaction by product is pure 200 proof ethanol, and its surprisingly easy to get it ethyl acetate free, just distil. I know there are so many ways of making acetic acid, for me this synth. is simply the easiest one for me, with no boiling down 20 liters down to one liter crap.

Enjoy : )

[Edited on 26-3-2014 by Have2Know]

HgDinis25 - 26-3-2014 at 13:35

That is one of the best ways to get OTC Acetic Acid and pure ethanol. I didn't even know you could buy that quantity of Ethyl Acetate, in such a pure form. I've never found any in my usual stores.
Anyway, I don't know if you know but you can use Sodium Bisulfate instead of sulfuric acid to produce the acetic acid. I would use Sulfuric Acid anyway, but just in case...

subsecret - 26-3-2014 at 14:12

Nice work! I've not been able to find any good ethanol, so I'm certain that I will use this method.

Remember that even if x grams equals one mole of one substance, x grams of another substance may not be one mole. Go by number of moles, as you described first, and not only by mass.

Steam - 26-3-2014 at 14:39

Nice work, were you going for pure glacial acetic acid?
A simple test to find the concentration of your acetic acid is to add some to sodium carbonate/sodium bicarbonate, If there is little to no reaction upon addition you have very pure glacial acetic acid, If it reacts and does the "volcano" reaction then you have a vinegar solution. Food for thought.

Dr.Bob - 27-3-2014 at 04:09

That is an excellent OTC prep of acetic acid. Thanks for posting it. Maybe you could write it up in a detailed experimental and take afew photos and post it on the experimental writeups section.

Spock - 27-3-2014 at 07:55

For the sodium acetate would it not be possible to use sodium hydrogen carbonate and dilute acetic acid. NaHCo3+CH3COOH->C2H3O2Na+H2Co3.

DraconicAcid - 27-3-2014 at 07:59

Quote: Originally posted by Spock

For the sodium acetate would it not be possible to use sodium hydrogen carbonate and dilute acetic acid. NaHCo3+CH3COOH->C2H3O2Na+H2Co3.

NaHCO₃+CH₃COOH->C₂H₃O₂Na+H₂O + CO₂.

That would work, but then you'd have to evaporate off a lot of water before going on to the next step.

forgottenpassword - 27-3-2014 at 13:09

Thanks for the write up. It is interesting as a source of duty free ethanol, rather than using methylated spirits.

*FWOOSH* - 28-3-2014 at 20:34

Glad to see you ended up posting this, it definitely makes GAA and Absolute Ethanol more OTC.

CaptainPike - 10-4-2014 at 15:09

I followed along pretty well to your very humorous and useful preparation of GAA (and EtOH). I would probably try doing this with regular glassware – only because I have it (plus I would probably lose further use of my extremities from the administration of my wife's "home correction program")

The only part I couldn't see clearly, was how the ice filled bowl, on top of the pot would return all the condensing vapors to the "still pot". If the perimeter of the bowl were bigger than that of the pot (which it would have to be) would vapors not drip down, ultimately outside the pan/pot?

And, if the free 200 proof ethanol weren't enough, ethyl acetate being an MEK substitute!?! How lucky is that? It's like the opposite of Murphy's Law. I'm going to check out our substitute, is probably Japan stripper or something– Murphy's Law is still alive and well here.

Thank you for posting.

CaptainPike - 10-4-2014 at 15:09

I don't know how to delete a post :-)

[Edited on 10-4-2014 by CaptainPike]

IrC - 10-4-2014 at 15:52

Quote: Originally posted by CaptainPike

I don't know how to delete a post :-)

[Edited on 10-4-2014 by CaptainPike]

You must do it under 24 hours from the initial post while you still see an edit button upper right of your post. Go to edit, scroll down, you will see a box to check '! Delete this message !'. Check it, select 'edit post'.

CaptainPike - 12-4-2014 at 09:51

okay so the KLEEN STRIP MEK substitute is, indeed, 100% EtOAC. This news is, by itself is worth the trip to the Home Depot. I didn't do so well with the sodium hydroxide. The drain opener, alkaline version was hypochlorite-based potassium hydroxide secondary.

What I'm more interested in however is writing out a balanced equation and understanding how the anhydrous ethanol and the glacial acetic acid are separated. There may not be azeotropes here – i.e., I see how one could distill off the ethanol, possibly, but wouldn't that leave the glacial acetic acid contaminated with ethyl acetate?

So, can the ethanol really be gotten out by simple distillation? I'm still very happy to learn about this saponification (?), since it provides a very inexpensive and elegant solution to a couple of little problems I have. Will you please provide a little more info on the "acid workup" part of this preparation? Such as, how much "pretty strong" sulfuric acid vs ice is needed. I may use my liquid fire drain opener sulfuric acid for this.

Attachment: 1636 KS MEK Substitute.pdf (28kB)
This file has been downloaded 846 times

hyfalcon - 18-4-2014 at 06:37

OP mentions phosphoric acid. Could the second step distillation be accomplished with 85% phosphoric acid instead on using the sulfuric acid, or would it still need to be diluted down to 75-80%? Another thought, If we are introducing a diluted acid into the equation then how do we expect to get absolute alcohol out of it also. With ethanol's affinity for water I don't see how you could get away with not picking of water out of the equation.

Bert - 18-4-2014 at 08:16

This is a nice piece of information, both for informing readers about the availability of cheap OTC ethyl acetate, and the production of near anhydrous ethanol & Sodium acetate/glacial acetic acid.

The procedure is understandable to me- And I can write out the equations. But OP could REALLY benefit from a little bit of an edit for clarity. Also, maybe include balanced equations? Perhaps a picture of your equipment setup? Brief mention of temperatures for the two products you're distilling off? The second distillation of the ethanol to separate from any remaining ethyl acetate?

[Edited on 18-4-2014 by Bert]

hyfalcon - 18-4-2014 at 08:23

Yeah, I figured out we were actually looking at two separate reactions here.

You're still going to be left with a mix of ethyl acetate and ethanol. That's going to be difficult to separate due to their close BP's. I don't know if vacuum would give you any separation in those BP's or not. I suspect it would and that's a wild guess, but ethyl acetate has a very low flash temperature. Someone correct me if I'm wrong, but doesn't that mean it begins emitting ethyl acetate vapor at that temperature at sufficient quantity that it can ignite? Ethanol's flash temperature is close to room temperature where ethyl acetate's, according to the pdf in this thread is sub-freezing. I would think there would be a way to take advantage of this with some careful vacuum distillation.

[Edited on 18-4-2014 by hyfalcon]

[Edited on 18-4-2014 by hyfalcon]

Oxirane - 6-11-2014 at 18:46

Ketene production was discussed in acetic anhydride topic. I became aware that acetic acid can be made by reacting ketene with water. Could this be a viable route?

CuReUS - 7-11-2014 at 03:22

Quote: Originally posted by Have2Know

. I just use a big stainless steel beaker, with an ice filled bowl on top to act as a reflux condensor. With this plopped into an ice bath and me stirring like mad I can control about 6 moles with confidence

are you sure this is a good idea for a condenser?
because i remember trying out the same thing back in high school while i was doing the cannizzaro reaction with benzaldehyde and NaOH(i had put a china dish filled with ice cold water on the mouth of an erlenmeyer flask but though some of the vapors were condensing ,most of it was escaping (as i could smell the benzaldehyde)

also you say that you use a stainless stell vessel to run the reaction so i am assuming that it has only one mouth .so how can you stir the reaction mixture when the ice bowl is covering the mouth?

Quote: Originally posted by Steam

A simple test to find the concentration of your acetic acid is to add some to sodium carbonate/sodium bicarbonate, If there is little to no reaction upon addition you have very pure glacial acetic acid, If it reacts and does the "volcano" reaction then you have a vinegar solution. Food for thought.

steam ,is it because as glacial acetic acid is so strong ,it will not ionize at all and hence not react?

Quote: Originally posted by Oxirane

Ketene production was discussed in acetic anhydride topic. I became aware that acetic acid can be made by reacting ketene with water. Could this be a viable route?

yes that is a viable route ,but ketene is very toxic

SimpleChemist-238 - 7-11-2014 at 05:30

When I require ethyl acetate, I don't like to spend large amounts of funds on large quantity's of reagents so I buy smaller amounts in stores. I purchase non-acetone nail polish remover but its not very pure so fractional distillation is required. First to come over is the fragrance, once all of it is over replace the receiving flask and collect the rest which is all ethyl acetate. A brown stuff will leave a residue in the boiling flask but it is easy cleaned. You will yield 200ml of some what dry ethyl acetate.

Ethyl acetate hydrolysis

Dronami_inc - 22-11-2014 at 09:32

Good day for all (i hope) and i have a question about ethyl acetate hydrolysis to obtain pure ethanol and acetic acid (glacial = desirable).
Both are relatively complicated to buy here.
I have the opportunity to build more or less complex apparatus.

Question A: Is there possible way to hydrolyse it using only water(steam) and catalyst, condense and then fraction distllation of mixture consists of unreacted EtAc, Acetic acid and ethanol?

Question B: In practice while using NaOH solution (or NH4OH to get acetamide) for EtAc hydrolysis, what byside products form? Because yield is not so high.

S.C. Wack - 22-11-2014 at 10:12

The are no byproducts, other than the usual byproducts in the case of acetamide from ammonium acetate, which needs a certain following of protocol for good yields or else you'll lose all your ammonia, which you'll lose a lot of when starting with an aq. solution instead of dry ammonium acetate salt. The separate ethyl acetate layer should completely disappear. Reflux with NaOH shouldn't leave any unreacted ester whatsoever. If there's any left, the reflux time or concentration or excess of NaOH wasn't enough.

Dronami_inc - 22-11-2014 at 10:57

Thank you.

Consequently in case of NaOH I'll get 95% spirit and NaOAc as a solution with yields not far from 100%.

And what about question A? Need Acetic acid and Ethanol as technical quality products in one step

blogfast25 - 22-11-2014 at 13:48

Quote: Originally posted by S.C. Wack

The separate ethyl acetate layer should completely disappear. Reflux with NaOH shouldn't leave any unreacted ester whatsoever. If there's any left, the reflux time or concentration or excess of NaOH wasn't enough.

So you reflux the ester straight over pure NaOH? No water whatsoever? If so, is it practical to distil off the EtOH while hydrolysis in on-going?

[Edited on 22-11-2014 by blogfast25]

unionised - 22-11-2014 at 14:08

I'd bet on that producing side products.
http://en.wikipedia.org/wiki/Claisen_condensation
(and by analogy with this)
http://www.orgsyn.org/demo.aspx?prep=cv1p0199

Also the boiling points of ethanol and its acetate are very similar so you won't be able to distil out the ethanol as it's formed

Bert - 22-11-2014 at 14:13

The production of ethanol and glacial acetic acid from (cheap!) over the counter ethyl acetate and sodium hydroxide was discussed recently at some length...

I will be merging this thread with the above linked thread shortly.

blogfast25 - 22-11-2014 at 14:20

Quote: Originally posted by unionised

I'd bet on that producing side products.
http://en.wikipedia.org/wiki/Claisen_condensation
(and by analogy with this)
http://www.orgsyn.org/demo.aspx?prep=cv1p0199

Also the boiling points of ethanol and its acetate are very similar so you won't be able to distil out the ethanol as it's formed

So, refluxing the EtOAc with say 50 % NaOH, followed by fractioning off the EtOH azeotrope? Sound like a route to fairly pure EtOH I've never considered.

[Edited on 22-11-2014 by blogfast25]

S.C. Wack - 22-11-2014 at 14:40

Quote: Originally posted by blogfast25

So you reflux the ester straight over pure NaOH? No water whatsoever? If so, is it practical to distil off the EtOH while hydrolysis in on-going

Does not the thread title "ethyl acetate hydrolysis" and my own word "concentration" imply water...so I didn't put an "aq." before NaOH...

There's probably an ester hydrolysis in whichever lab manual; there happens to be one in Systematic Organic Chemistry that works.

Dronami_inc - 22-11-2014 at 15:29

elegant solution

If I understand properly, author used solid NaOH (not a solution)?
If so, obtained ethanol and acid are almost completely waterless. Please correct me if this is not so.

...I skiped this topic by accident and created a new thread https://www.sciencemadness.org/whisper/viewthread.php?tid=47958 where i'am interested in obtaining both anhydrous ethanol and glacial acetic acid, but probably using gas phase hydrolysis with catalyst. How can it be implemented? i.e. without NaOH involved

Dronami_inc - 22-11-2014 at 15:39

Thanks for all, the question A is still on the agenda

Bert, I took your suggestion and continued that branch

By the way, how do you think, what impurities other than water contained in technical EtAc?

blogfast25 - 23-11-2014 at 07:07

Quote: Originally posted by Dronami_inc

Thanks for all, the question A is still on the agenda

It's probably not possible.

Neat and Cheap – EtOH, GAA!?

CaptainPike - 25-12-2014 at 21:21

Okay, I'll probably appear to be cocky,this is not my intent, but could this thing be as perfect as it seems? I'm new at this stuff, so I need help. I wanted to describe a summary of my intention. Please slap me around, where necessary.

First, a kind of Claisen condensation, of ethyl acetate with itself using a sodium hydroxide catalyst, is attempted. May as well go with a one molar first run.
I'll set up for reflux, but have an ice bath ready, with one mole ethyl acetate( 98.23 mL) in a suitable(at least 2neck) RBF, say 500 mL. I'll use my good, trustworthy reflux condenser and top it off with a calcium chloride guard tube.
I'll begin with moderate stirring and then add a small amount of my 40 g sodium hydroxide – POWDER, no aqueous solution. Observe the temperature of the reaction mixture and add this mol of NaOH.

If I get 20 g sodium hydroxide in the stirring mole of EtAOc without appreciable temperature rise, I will hold here. I will look for signs of some kind of reaction and perhaps the precipitation of sodium acetate prills.
If also, the thing begins refluxing exothermiclly, I will be happy, I will attempt to keep the reaction temperature under control(77 – 78°C) with an ice bath. I believe that at this point the ethyl acetate will be beginning to be replaced by dry ethanol.
I will continue addition, until I've added the whole mole of sodium hydroxide. When the temperature begins to cool off, I may even heat this reaction mixture. I can measure the pH, and odor (I told you, I'm new here).

Just judging things, I may continue refluxing. I'm not sure whether I need two equivalents of the ester, since I'm reacting it with itself. But it seems like one acetate ion will be created by the condensation of each example of ethyl acetate.

The great thing about this is the possibility that we will be refluxing nearly completely ethanol at the endpoint and all of the sodium ions will be hooked up with acetate ions. At this point I will treat the reaction mixture as hygroscopic, and switch over to regular atmospheric distillation (still using a guard tube on the receiver. I think positive.) Theoretically I'll wind up with 58.4 mL dry ethanol.

Then (if by some a lark of a chance, or ultimately, after tuning) the still pot(having been very carefully distilled to dryness?) can be reset up with an air condenser and an addition funnel with an appropriate amount of concentrated sulfuric acid and distill off glacial acetic acid!

Okay, now throw stuff. I'm going to try this, so please, offer cautions, considerations, modifications, etc. This would be a really cost justified answer to the production of two elusive solvents which I need.

Some Notes:

1) even dry ethanol has some solubility for anhydrous sodium acetate. But surely, the atmospheric distillation with a double-sided, efficient condenser should leave the solid material behind, right?

2) if the first reaction works and goes to completion,, then we won't have to worry about an ethyl acetate/ethanol azeotrope (EtOAc will be gone). I don't expect much trouble separating excess concentrated sulfuric acid from GAA.

3) But, can we do the first reaction with no water? I think the use of an aqueous solution of sodium hydroxide leads to watery results, that are difficult to get rid of. The idea of creating ethanol in an environment where water can't be formed is very intriguing.

4) It's damned convenient, about the boiling points of these two organic compounds. I mean, ethyl acetate boils at 77°C and ethanol just about 78°C. It's terrible (impossible really) if you're trying to fractionate them apart. But of one is being converted to the other – it's just too convenient, makes me suspicious.

[Edited on 26-12-2014 by CaptainPike]

This is too easy

Yugen - 26-12-2014 at 08:45

What isn't already easy about making ethyl acetate? It's simple Fischer esterification. Aren't there already free resources for this synthesis everywhere? Check out page 73 of this free google ebook for example.

Is it the procurement of glacial acetic acid that bothers you?

smaerd - 26-12-2014 at 09:17

Uhm I am totally confused. It looks like captian pike wants to create ethanol and glacial acetic acid from ethyl acetate. I'm just entirely confused why this post is here?

I don't know where to comment about the uhm... prep. Here or in the link?

CaptainPike - 26-12-2014 at 13:31

THERE! I have officially gotten tomatoes thrown at me

Are you talking to me?

Bert - 26-12-2014 at 17:20

See your PM, not throwing tomatoes!

CaptainPike - 31-12-2014 at 19:14

Does anybody believe this reaction can occur (and go to completion) in a reaction media of ethyl acetate which changes to ethanol in the end?

CH3COOCH2CH3 + OH- ––––> CH3COO- + CH2CH3OH

I mean will the saponification continue with the last hydroxide ion attacking the last carboxyl? Or should I have an excess of either reagent?

I think it would be wonderful if the whole thing could occur with no water at all! But will it ever actually complete? And Yes, I am "of age", able to buy booze, etc. etc. I just want to understand this reaction better. I also would like to see some glacial acetic acid (that I created) going in and out of a solid form at somewhere around room temperature – don't you think that is cool?

And Another Thing – what if ethanol forms complexes with lye? And I mean, after the collapse of the tetrahedral, is there some way to protect the newly formed ethanol from having its hydrogen(from the OH) abstracted or otherwise interfered with by the ongoing reaction?You can probably tell I have very little experience in organic chemistry, either practical or hypothetical

PS: Happy New Year :-)

[Edited on 1-1-2015 by CaptainPike]

GAA/ethanol prep – Harmless Home Lab Version

CaptainPike - 11-1-2015 at 12:41

Background
A one mole scale experiment was performed along the lines of a procedure posted by have2know, Acetic Acid Synth. Easy Home Version.

Have2Know's post outlined a two step process, first, the saponification of ethyl acetate by way of sodium hydroxide yielding sodium acetate and ethanol and second, the pyrolysis (?) of the sodium acetate to make glacial acetic acid (either using sodiumbisulfate or concentrated sulfuric acid). I intend to do both parts of the experiment, but only the first part has been so far attempted, and outlined here.

Some Initial Calculations and Assumptions
One mole of ethyl acetate, having density 0.897 and molar mass 88.11 grams/mol. 88.11 g of ethyl acetate will be 98.23 mL.
One mole of sodium hydroxide, in solid form 39.997 g/mol
one mole of ethanol having density 0.789 g/cm³ and molar mass 46.07 g would be 58.39 mL.

EQUATION: CH3COOCH2CH3 + OH- ––––> CH3COO- + CH2CH3OH [1]

MECHANISM: attack by a hydroxyl group – tetrahedral intermediate – kicked out alkoxide with rapid proton transfer creating the alcohol (resulting in acetate ion) [2]

What I Did

In a nice, heavy, two necked, 250 mL round bottom flask was placed just under 40 g (one mol) sodium hydroxide in fine prills. This flask having one major, central neck and the other splayed off to the side, was fixed just above a stirring hot plate, but initially in an ice bath. A thermometer was placed in the off vertical neck, with the bulb extending below the midpoint of the flask but above the activity area of a stir bar which was then also added. An efficient reflux condenser was fitted in the central, main neck and the circulation of ice water was begun. All tapered glass where joints were greased with high temperature vacuum grease.

After a short time, roughly 99 mL (1 mol ) of hardware store ethyl acetate (Klean Strip MEK Substitute) was added in two separate approximately equal additions. After a couple of minutes of heavy stirring, the 40 g of NaOH was suspended as a slurry in the one half mol of ethyl acetate. The suspension remained at a temperature of 11°C with little or no exothermic action so the other portion of ethyl acetate was added, and a thermometer adapter reinserted.

The ice bath was removed and the flask was heated gently on air bath. Shortly after reaching about 70°C, obvious refluxing began. This was allowed to continue for approximately 2 hours after which time the liquid phase became limited and the solid volume increased markedly. Heating was increased moderately in an attempt to melt the growing mass of crystals. Magnetic stirring was insufficient to move this mass significantly. Very little liquid remained but this did continue to reflux.

The heating was stopped and a calcium chloride guard tube was added to the top of the reflux condenser to prevent the entry of moisture.

Observations And Discussion

One of the goals of this experiment was to produce ethanol and sodium acetate in an anhydrous form. Instead, some of the white solid material was charred and darkened possibly due to oxidation. Very little liquid seems to exist separately from the wet solid.

I am at a loss as to what has happened. I could find no reference to any attempt at performing this saponification with no water added to the initial liquid phase. My guess is that the reaction is halted somewhere short of completion. The still pot smells strongly, as one might expect, somewhere between the ester and the alcohol. The crystals do appear damp and there is some liquid remaining. It was calculated that 58 mL of ethanol would result from 100% conversion.

I attempted to put some litmus paper to a sample drawn out shortly after stopping. I'm not sure what it means the stuff is wet but not with water and doesn't seem too weep into the paper. It may have represented significantly alkaline conditions.

I have some photos. Something I've noticed since halting a couple of days ago. It seems as though the charred coloring has pervaded an ever enlarging mass of crystals. Meaning, initially a dark spot was on the bottom, now the whole large mass of crystals has taken on the discoloration almost evenly. A photo was taken shortly after shutting down using a cell phone. Then, I took some photos today with a somewhat better camera and a lower aspect. Lighting, resolution, angle, camera and time are all changed, so surely my perception is subjective. But clearly the volume of white material is larger now than when we halted a couple of days ago.

I also include a shot of my calcium chloride drying arrangement – I wanted to get something on there quick, before cooling down drew in appreciable air. I wasn't able to pack my tube, plus, it's "college rule" (19/22). That adapter is a nice fritted bubbler (I had lying around), that fits perfectly into that oddly shaped Erlenmeyer flask (stem almost touching the bottom). The barbed end of the fitted tube is unfortunately off screen, but leads through a short piece of rubber tubing to a little 14/20 gas fitting in the top of the condenser.

And speaking of condensers, that little bantumware 14/20 reflux condenser is a really nice rig. It doesn't sweat but you can drive a lot vapor into it and you won't even smell solvent in the room.

What to Do Next

I'm thinking I will rearrange the setup for normal distillation and pull off what liquid I can.

Alternately, I could add in some more dry ethanol , chop up the mixture with a stirring rod and try refluxing some more – push the reaction further to the right?

Maybe this worked! I'm sure if there was pure ethanol, I have probably lost some through evaporation – could that really happen through the calcium chloride packed tube? I could distill to dryness (using a heating mantle, instead of the hot plate?) and then continue with the pyrolysis using concentrated sulfuric acid.

I could add in the slight excess of sodium pyro sulfate, begin the dry distillation, pulling off a for-run of whatever liquid is still present, and then collect glacial acetic acid. (Well, it might happen!)

Questions

1) is this even possible – to do this reaction with no water? That is, starting with an ethyl acetate reaction media, then having this diluted with the newly formed ethanol, ultimately ending in pure ethanol?

2) Relating to above, can I expect this theoretical reaction mechanism [2] to continue, unaffected by the increasing concentration of ethanol being formed?

I would really appreciate any comments, suggestions, etc. I still haven't done anything else yet.

References
1. Chemical Engineering Education, Summer 2004, page 228
2. http://www.colby.edu/chemistry/PChem/lab/KineticsEster.pdf

sodium acetate crystals maybe closer look.jpg - 136kB

calcium chloride guard tube arrangement.jpg - 245kB

gdflp - 11-1-2015 at 12:53

This is a nice writeup, but why did you start a new thread? This is an identical topic and similar scale to the thread you mentioned.

CaptainPike - 11-1-2015 at 13:04

Yes, I started a new thread.

Maybe as you imply, it should be just a post in the thread that I indeed mention.

It is basically the same thing done by have-two-know, but it's also different in that is done using glassware, etc. If the powers that be think it should be moved in, as a post, or elsewhere, it is OKAY by me. I did have some discussion with O Most Powerful One, and I think it will stand alone. I thought it might be better off over in the organic branch, even. So we shall see. Thank you.

CaptainPike - 13-1-2015 at 17:08

Quote: Originally posted by Dronami_inc

elegant solution

I got nowhere with this link. Is it dead, has it been moved or am I not allowed?

I'm trying to figure out whether this process can be done using pure lye, not a 50% solution or something. Once we start adding water ethanol doesn't give it up so easily (nor does sodium acetate!)

I'd be interested in the opinion of S.C.Wack and others possibly following this discussion.

S.C. Wack - 14-1-2015 at 15:27

People always regret my opinionating. There is a way to do things and a way to isolate things and you're not there. You need lab manuals. This is why I scanned several of them. Note the book that I suggested. And that there is a www button here. Perhaps djvu plugins are still available.

20 g of ethyl acetate are refluxed with 80 g (excess) of 25% aqueous caustic potash for 1 hour, until the layer of ester has disappeared, and the mixture no longer smells of it. The whole is then distilled to 100°; ethyl alcohol can be separated from the distillate by addition of anhydrous potassium carbonate. The residue in the flask is neutralised with dilute sulphuric acid and evaporated to dryness on a water bath. The solid residue is powdered and distilled with 50 g of conc. sulphurlc acid to 130°, and the distillate fractionated between 115° and 120°.

Cooling in ice until solidification takes place, and subsequently draining away the still-liquid portion, gives crystals of glacial acetic acid.

Yield.-90% theoretical (12 g). Colourless liquid or crystals; characteristic odour; miscible with water; mp 16.7°; bp. 119°

CaptainPike - 15-1-2015 at 12:05

That wasn't too bad a, "Whack", after all!

Thank you, S.C., for the following procedure, which makes sense. I do have a handful of questions about what you have said which follows.

Quote: Originally posted by S.C. Wack

20 g of ethyl acetate are refluxed with 80 g (excess) of 25% aqueous caustic potash for 1 hour, until the layer of ester has disappeared, and the mixture no longer smells of it. The whole is then distilled to 100°; ethyl alcohol can be separated from the distillate by addition of anhydrous potassium carbonate. The residue in the flask is neutralised with dilute sulphuric acid and evaporated to dryness on a water bath. The solid residue is powdered and distilled with 50 g of conc. sulphurlc acid to 130°, and the distillate fractionated between 115° and 120°.

Cooling in ice until solidification takes place, and subsequently draining away the still-liquid portion, gives crystals of glacial acetic acid.

Yield.-90% theoretical (12 g). Colourless liquid or crystals; characteristic odour; miscible with water; mp 16.7°; bp. 119°

Some Questions On the above:

1.) can I use sodium hydroxide ("caustic soda")?I have this on hand. Although it would seem that 80 g would be a lot of lye to use with 1/2 mol EtOAc – straighten me out on this?

2.)What exactly is a 25% aqueous caustic potash? How do I prepare, "80 g of 25% aqueous"?

3.) "the whole is then distilled to 100°" – does that mean as opposed to dryness? The still pot temperature or the still head temperature (going into the condenser)? You mean normal distillation and the temperature will rise and I stop at 100°C? Right?

4.) It seems like there will be more water (from that 25% aqueous solution of sodium or potassium hydroxide) in the distillate then can be absorbed by a drying agent such as potassium carbonate. Oh, maybe that's why you say, "to 100°". My experience with distilling aqueous solutions of ethanol says that if I take the fraction up to 100°, there will be appreciable water in the distillate.

5.)I always thought CaO was the best drying agent for ethanol. Is potassium carbonate better? What about sodium carbonate… and can I dehydrate that to the anhydrous form by baking in a conventional oven to 525°F? I have some washing soda here on the farm. [Shucks]

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Help with any of these questions will be greatly appreciated.

I blundered on blindly and drew about 25 mL of some clear liquid that came over around 78° from my yellow colored sticky snow. I used an interesting recombination of my apparatus and provide a crow's nest view of the set up. I have a lot to learn, but it sure is fun.

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S.C. Wack - 15-1-2015 at 19:32

The idea with the potassium carbonate is to form (at least) a saturated solution and separate layers, like NaCl and IPA. I've never tried sodium carbonate. Hopefully you can figure out everything else.

aga - 26-5-2016 at 11:37

I tried this process a couple of times to obtain water-free EtOH over the past 2/3 days at a 2 mol scale.

In practical terms, the NaOH prills do swell up, presumably trapping any EtOH formed, as it becomes a solid lump.

Strong heating in a disty rig didn't even get close to any distillate after 10 minutes, and i suspect (not looked it up) expansion co-efficients would end up with more cracked glass than product, so i stopped. (value the glass more than the booze).

When the solid mass was broken up there was still the distinctive smell of ethyl acetate.

The easiest way to get the lump out of your glassware is to add water, which kind of makes it useless for anhydrous EtOH production for an amateur.

Strong heating was noticed when the water was added, so presumably a lot of unreacted NaOH as well.

At a 0.25 mol scale or less, this reaction will probably work (for getting anhydrous ethanol) if stirred strongly for 24 hrs and with pure reagents.

For producing sodium acetate, it does work, although at bigger scales the yield of sodium acetate will be limited by how well you can thoroughly mix slightly damp solids whilst controlling the temperature.

Personally i'll stick to vinegar/sodium bicarb and a lot of boiling, then a recrystallisation or two.

[Edited on 27-5-2016 by aga]

halogen - 26-5-2016 at 15:09

EtOAc + NaOH -> heat + other stuff
NaOAc + H2SO4 -> heat + other stuff

"there has to be an easier way!"

Maybe you could polymerize it in a hot tube to split off ethylene.