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Hydrolysis of ethyl acetate to ethanol

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steppa

steppa

Rising Star
Hey Nexus,

I just read that ethyl acetate with NaHO can yield relativly pure and clean ethanol. As ethanol is pretty expensive arround here I thought this might be an alternative way to just buying pure ethanol.

5l of ethyl acetat cost arround 25€ here wheras a half litre of ethanol is sold for arround 10€.

So...as I am not too knowledgable about chemistry I thought I might ask the more knowledgable people over here if this might be a way for a chemistry layman to get his hands on cheap ethanol. What do you think about this?
 
I've been meaning to try this too, but haven't gotten to any actual experiments. But I've read a little about it on some sites (mostly on sciencemadness.org).

You will need a distillation apparatus and a reflux column for this I think. Decanting before hydrolysis is complete will give a mixture of ethanol and ethylacetate. After hydrolysis is complete there will be NaOH dissolved in the ethanol.

A molar excess of NaOH is needed to ensure that all ethylacetate is converted.

From what I have read, performing the reaction is a little tricky, in that it may not start immediately. When it does start, it generates heat, which accelerates the reaction. So, doing this on a large scale and adding all of the NaOH at once will probably cause a mess, with the reaction running out of control. Be careful.

You need to keep the ethylacetate under reflux, slowly adding NaOH as it is being converted. When the NaOH is no longer being consumed, keep the reaction for at least an hour under reflux to ensure that the hydrolysis is complete. Then you can safely distill off the ethanol.

If the hydrolysis is incomplete, you're likely to get a lot of ethylacetate in the distilled ethanol, because the boiling points of both are quite close.

If you can keep atmospheric moisture out of the reaction and distillation, you should be able to get reasonably anhydrous ethanol.
 
Thanks benzyme.

I read that it works with a waterbath at 50°C.

The process seemed to be fairly simple from what I read. Basically mixing ethyl acetate with NaHO solution and putting it in a waterbath, right?

From what I understood the ethanol should cleanly separate itself from the rest then.

Would the process make sense in regard of cost/work efficiency?
 
pitubo,

that sounds a bit different from what I read. I think I'll have to do some more reasearch. If it has to be made like you discribed it, I'll refain from doing it. Thank you.

If you can keep atmospheric moisture out of the reaction and distillation, you should be able to get reasonably anhydrous ethanol.
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I don't really need it anhydros. But good to know.
 
steppa said:
pitubo,

that sounds a bit different from what I read. I think I'll have to do some more reasearch. If it has to be made like you discribed it, I'll refain from doing it. Thank you.

If you can keep atmospheric moisture out of the reaction and distillation, you should be able to get reasonably anhydrous ethanol.
Click to expand...

I don't really need it anhydros. But good to know.
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That's not going to happen, since it azeotropes with water. You can achieve greater than 95% but it'a hygroscopic and will restore its azeotrope. Ethanol is easilly obtainable from a nutrient rich sugar wash and turbo yeast.

Then you don't have to abuse ethyl acetate.
 
1ce said:
That's not going to happen, since it azeotropes with water.
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It might. There's no azeotrope with water if the water isn't there to start.

CH3COOCH2CH3 + NaOH -> CH3COONa + CH3CH2OH

Where's the water in that?

1ce said:
Then you don't have to abuse ethyl acetate.
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If reasonably pure ethylacetate and lye are cheap and easily available, it may beat the hassle of getting nearly anhydrous ethanol from some broth that possibly also contains methanol and fusel alcohols.
 
Sodium hydroxide is pretty darn hygroscopic...

Pop some in a drying tube to keep your reaction dry? :)

(Although NaOH + CO2 = NaHCO3 essentially puts a stop to that.)
 
Broth? I just cetrifuge the yeast (large tubes..) and decant through a buchner directly into a boiling flask. Then I'll distill to ~70% EtOH and fraction it off raschig rings to the azeotrope. Have you considered soxhleting the water through a sieve, or drying it over a desicant?

What is so damned hard about distilling a 10$ bottle of monarch? This is a terrible waste of NaOH/EtOAc!
 
1ce said:
Broth? I just cetrifuge the yeast (large tubes..) and decant through a buchner directly into a boiling flask. Then I'll distill to ~70% EtOH and fraction it off raschig rings to the azeotrope. Have you considered soxhleting the water through a sieve, or drying it over a desicant?

What is so damned hard about distilling a 10$ bottle of monarch? This is a terrible waste of NaOH/EtOAc!
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Lucky you with your centrifuge! I'm with you on distilling - loads more fun than mucking about with NaOH.
 
downwardsfromzero said:
1ce said:
Broth? I just cetrifuge the yeast (large tubes..) and decant through a buchner directly into a boiling flask. Then I'll distill to ~70% EtOH and fraction it off raschig rings to the azeotrope. Have you considered soxhleting the water through a sieve, or drying it over a desicant?

What is so damned hard about distilling a 10$ bottle of monarch? This is a terrible waste of NaOH/EtOAc!
Click to expand...
Lucky you with your centrifuge! I'm with you on distilling - loads more fun than mucking about with NaOH.
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Brand new centrifuge was vastly cheaper than you might believe. You can setup 2liter pop bottles with turbo yeast for 20% ethanol. Save the yest for the next fermentation.
 
downwardsfromzero said:
Smart solution. What centrifuge is it?
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3x 100ml 'fuge. 4500rpm.

I'm not going to name names of products on a public drug forum, though.
 
You spin down your yeast in 300mL batches?

I suppose the turnover of such products is somewhat limited. I'll listen to my own advice and look it up for myself 😉
 
downwardsfromzero said:
You spin down your yeast in 300mL batches?

I suppose the turnover of such products is somewhat limited. I'll listen to my own advice and look it up for myself 😉
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The yest mainly settles to the bottom of the bottles, and it only takes a couple minutes apiece. You don't have to be exact since you're going to immediately distill it anyway.

I've found centrifuging useful for breaking emulsions, and even nice for hot dmt saturated heptane.
 
1ce said:
What is so damned hard about distilling a 10$ bottle of monarch?
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I don't know what "monarch" is. If it's a cheap alcoholic drink it woudn't make sense to use this. Due to liquor tax one wouldn't save anything.

NaOH/EtOAc are dirt cheap and easy to get. The EtOAc I found has a purity of 99,2%. My guess is that it would be pure enough to be used. But due to the conversation drifting away from it's original topic I'm still unsure about the process itself and if the process could be utilised by an avarage kitchen chemist without too much gear.

Any words on this?
 
I found a video of the process on youtube. 😁

The actual Process starts at 2:50 min. Although refluxing is involved it doesn't seem to be overly complicated.

[YOUTUBE]
 
Okay, you asked for our opinion, so here is mine.

Don't bother. As you stated earlier about distilling dirty cheap gin or vodka due to fusels (learn to distill?) being in your end product. Your end product here would be contaminated with isopropanol and other compounds. Vodka wouldn't be any more expensive than the reagents required for this reaction. He got what? 200ml or so EtOH? Why bother when I could distill 800ml EtOH from 14$ worth of vodka. And I'll wager it cost more 'round my parts.

If paying the 'gubmint tax' is too hard on you, do what I do and brew your own.

12$ worth of yeast.
11$ worth of nutrients.
16$ worth of sugar.
____________________________
= 1200 liters azeotropic EtOH approx.

The distillation for this reaction yields more contaminated, still azeotropic ethanol. No dryer than if you started with vodka. I use ethanol in the synthesis of Et2O and ironically.. EtOAc. DOH!

I've given you my advice, do what you'd like with it.
 
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