VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
Could we dry ethanol with Zinc?
There certainly something I might be missing, but, if we put a few chunks of freshly cut zinc in 98.0% Ethanol, and bring the temperature up in a
pressure cooker, would that be enough to dry it to >99.9% Ethanol?
Would we need etchant vs newly formed oxide on the surface?
I'm thinking zinc is less reactive than magnesium, so it would be safer to distill after filtration if it works.
|
|
|
clearly_not_atara
International Hazard
Posts: 2691
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
I do not think that ethanol will get through that oxide layer. Zinc powder has a chance, but a small one unless it's activated just before use. Zn/Ga
amalgam would work, but that's a waste of gallium.
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
MadHatter
International Hazard
Posts: 1332
Registered: 9-7-2004
Location: Maine
Member Is Offline
Mood: Enjoying retirement
|
|
Home Fuel Distillation
Running your EtOH through anhydrous rock salt can remove water but I'm not
sure how much. The rock salt can be left out in the sun afterward to dry out.
This is 1 of the methods that home distillers(for fuel) use. It really depends on
your intended use. And, no, I didn't distill it for my car. 
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
|
|
|
Texium
|
Thread Moved
29-7-2022 at 12:40 |
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by MadHatter  | Running your EtOH through anhydrous rock salt can remove water but I'm not
sure how much. The rock salt can be left out in the sun afterward to dry out.
This is 1 of the methods that home distillers(for fuel) use. It really depends on
your intended use. And, no, I didn't distill it for my car.
|
That's interesting. I would definitely not feel safe putting in my car stuff that's been in contact with sodium OR chloride. Neither did I know it
could be used as dessicant (I did however know it was hygroscopic, for having lived in humid climates).
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by clearly_not_atara | | I do not think that ethanol will get through that oxide layer. Zinc powder has a chance, but a small one unless it's activated just before use. Zn/Ga
amalgam would work, but that's a waste of gallium. |
Is there anything that would etch the oxide layer, maybe I2? (ZnI2 is soluble in both water and ethanol, and I2 is used in conjunction with Mg for the
same purpose)
[Edited on 30-7-2022 by VeritasC&E]
|
|
|
Rainwater
National Hazard
Posts: 798
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
I use Epson salt, dried in an oven for a few hours then crushed.
It can be added directly to the ethanol and then distilled.
I try to keep a ratio of 3:1 by weight. Salt vs water. I don't think zinc would do it by itself. At least not in a reasonable amount of time.
"You can't do that" - challenge accepted
|
|
|
PirateDocBrown
National Hazard
Posts: 570
Registered: 27-11-2016
Location: Minnesota
Member Is Offline
Mood: No Mood
|
|
Your best bet is Mg powder. It works cold, but you can reflux, then distill off the alcohol.
Phlogiston manufacturer/supplier.
For all your phlogiston needs.
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Rainwater | I use Epson salt, dried in an oven for a few hours then crushed.
It can be added directly to the ethanol and then distilled.
I try to keep a ratio of 3:1 by weight. Salt vs water. I don't think zinc would do it by itself. At least not in a reasonable amount of time.
|
That is indeed probably the best way to get rid of the bulk of the water, but to make fully anhydrous ethanol you need to use one of different
techniques after that.
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
Mg powder likewise produces an ethoxide, and as you say, it probably works much better/faster cold than with zinc, because magnesium is more reactive.
My idea is that if it is feasible to trade magnesium for zinc, then we might trade some drying speed for safety (in distilling it afterwards), for an
equal (full drying) result (precisely because zinc is less reactive).
|
|
|
unionised
International Hazard
Posts: 5102
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
Is it just me or is " bring the temperature up in a pressure cooker," a bit worrying?
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
| Quote: Originally posted by VeritasC&E |
Mg powder likewise produces an ethoxide, and as you say, it probably works much better/faster cold than with zinc, because magnesium is more reactive.
My idea is that if it is feasible to trade magnesium for zinc, then we might trade some drying speed for safety (in distilling it afterwards), for an
equal (full drying) result (precisely because zinc is less reactive). |
If zinc would react with the water, what would stop it from forming ethoxide afterwards?
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Tsjerk | | Quote: Originally posted by VeritasC&E |
Mg powder likewise produces an ethoxide, and as you say, it probably works much better/faster cold than with zinc, because magnesium is more reactive.
My idea is that if it is feasible to trade magnesium for zinc, then we might trade some drying speed for safety (in distilling it afterwards), for an
equal (full drying) result (precisely because zinc is less reactive). |
If zinc would react with the water, what would stop it from forming ethoxide afterwards? |
I don't know, which is why I'm asking. My assumption is that the solubility in ethanol would be fairly low, such that the ethoxide would react with
water and then saturate the ethanol at a fairly low solubility value, which would slow down to near nothingness further reaction.
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
Just a little bit above the BP of water. No worries.
Only ethoxide + water + flammable liquid inside, what could go wrong? ^^
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Tsjerk | | Quote: Originally posted by VeritasC&E |
Mg powder likewise produces an ethoxide, and as you say, it probably works much better/faster cold than with zinc, because magnesium is more reactive.
My idea is that if it is feasible to trade magnesium for zinc, then we might trade some drying speed for safety (in distilling it afterwards), for an
equal (full drying) result (precisely because zinc is less reactive). |
If zinc would react with the water, what would stop it from forming ethoxide afterwards? |
PS: Note that Zinc doesn't react with water, zinc ethoxide would.
|
|
|
PirateDocBrown
National Hazard
Posts: 570
Registered: 27-11-2016
Location: Minnesota
Member Is Offline
Mood: No Mood
|
|
The whole point is to make the ethoxide, because the ethoxide will react with any water, destroying it, and regenerating the alcohol. Meanwhile the
metal oxidizes.
If you want dry ethanol, Mg is the classically preferred route.
Phlogiston manufacturer/supplier.
For all your phlogiston needs.
|
|
|
ErgoloidMesylate
Banned
Posts: 89
Registered: 8-8-2022
Location: Norad
Member Is Offline
Mood: Freedom of thought is priceless - You can't afford it
|
|
| Quote: Originally posted by PirateDocBrown | The whole point is to make the ethoxide, because the ethoxide will react with any water, destroying it, and regenerating the alcohol. Meanwhile the
metal oxidizes.
If you want dry ethanol, Mg is the classically preferred route. |
Don't know why you needed to state that, as everyone should already know all these things:
https://www.youtube.com/watch?v=NMfs3e9OdZQ
|
|
|
Bedlasky
International Hazard
Posts: 1219
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
Maybe because he want to explain it? Not everyone know this. This is purpose of this forum - to learn something.
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
Thank you for putting up this link, I didn't go through the trouble of finding an explanation for why the formation of the alkoxide is irrelevant
here, but you did and Doug explains it perfectly.
When there is water present, no alkoxide will be formed. Sure, alkoxides will react with water, but none will form as long water is there.
|
|
|
clearly_not_atara
International Hazard
Posts: 2691
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
| Quote: Originally posted by Tsjerk | | Quote: Originally posted by VeritasC&E |
Mg powder likewise produces an ethoxide, and as you say, it probably works much better/faster cold than with zinc, because magnesium is more reactive.
My idea is that if it is feasible to trade magnesium for zinc, then we might trade some drying speed for safety (in distilling it afterwards), for an
equal (full drying) result (precisely because zinc is less reactive). |
If zinc would react with the water, what would stop it from forming ethoxide afterwards? |
The relatively high
stability of ZnO versus MgO is my guess. The latter is attacked by acids much faster.
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
