I was reading a thread on mycotopia about extracting mushroom alkaoids with dry ethanol, and included was a tek showing how to make relatively dry ethanol w/o distilling or even heating anything. Something i never thought of before, really can't understand why this idea never crossed my mind before, but-

Dry MGSO4, and 80 proof vodka. In his tek he recommended putting chunks of dry mgso4 and the vodka in a blender, but that kinda freaked me out a bit. I don't play solvents and spinning electromagnetic motors that spark at times. Even if its not really all that flammable at the time.

Anyway, it still seems like a pretty sound idea. I've done it before with iso and acetone and it works pretty well. Your pulling out alot more water, (60%), but Epsom salts are cheap. And so is bottom shelf vodka. Granted its not going to be high purity or completely dry ethanol, but it should make it to everclear territory if you do it right.

As well it would be an easy and cheap method to get a food safe solvent that has many uses, or if you can distill a crude vodka, and use that to make your ethanol. That would be much more Eco-friendly imho. Safely of course, its not something I'm comfortable approaching in the near future without a lot more knowledge, and help from someone w/ experience.

definitely not advocating distilling high proof alcohol here, and don't recommend anyone try this unless they really know what they are doing. Want that to be clear. Its also an illegal act to do so in many countries.

but if you do so, distill a product comfortably below the ignition point of ethanol. Dry the rest of the water out without heat, or risk of explosions, with mgso4, and filter with activated charcoal if necessary to clean it up a bit.

Is this a viable method to obtain relatively dry and acceptably clean ethanol w/o resorting to distillation or buying it that way?

Any advice on how to go about this?

I was thinking of doing ~750ml of vodka, and at least 500g of completely dry mgso4. Would Start with 200g rough powdered mgso4, add it to a slightly larger container than the 750ml vodka bottle (1000ml), add 750ml vodka, seal and shake the hell out of the container, let it fully decant, overnight and pour off through a vac filter leaving most of the salts on the bottom. Then pour out the last little bit, and wash out the now wet mgso4 and a small loss of ethanol. Then fully dry the container.

Do this again twice each with 150g of mgso4, decanting, and filtering. Work fast as to avoid it sucking more water from the air. Then Drop a few chunks (75g?) of ethanol washed mgso4 (to prevent powder) to your final storage container. Filter the ethanol you used to wash the 75g of big chunks, quickly, and add it with the rest of the ethanol to the container.

The mgso4 should prevent any moisture from the air leaking in, and a wine preserver n2/argon flush couldn't hurt either. The ethanol wash should prevent particles of epsom salts and instead have largish chunks that don't take time to decant. However some particles will prob be there, so filtering or just not disturbing the bottom layer when taking some ethanol out of the container may be necessary.

Sounds like something that would work relatively well?

Any reasons why ethanol would behave differently than iso or acetone?
(i know theres prob differences, just not the chem knowledge as to why)

Any ideas on how dry it would be?

Any advice, commentary, or explanation of the science behind this idea is welcome, and appreciated

without going in-depth into the chemistry of intermolecular interactions, i'll just mention that ethanol has a stronger dipole moment
than either iso or acetone; because of this, it has stronger hydrogen-bonding interactions
with water. simply drying it with molecular seives or sulfate salts is not enough, you must
distill it in the presence of a solvent which has predominantly van der waals
interactions, an aromatic solvent

not sure at all if mgso4 will dehydrate aqueous ethanol. and without an alcoholmeter how would you gauge your progress?

http://h1946214166k102.c...0%20laborbörse.html

I have gotten 90% ethanol to 99% with 3a zeolite. room temp.

in industry there are several ways they achieve anhydrous ethanol. Distillation with a cosolvent (benzene), as Benzyme mentioned, and I think at least half of the usa production utilizes columns of modified corn grits that dehydrate ethanol vapors. they are then regenerated with superheated inert gas (CO2). Zeolites are also used, and regenerated in a similar fashion. probably using heat, vacuum, and inert gas.

there are other ways--quicklime, cellulose, etc, but getting anhydrous is difficult, to say the least.

start with the highest proof you can find.

darn, i was really hoping this would work. ive been imagining all sorts of new uses for dry ethanol as my disposal, but alas, they are for naught.

Shulgin said that research indicated ~70% etoh was optimal for mushroom extraction. At ~99% etoh, the researchers found the efficiency of the extraction dropped to almost 0. Anyone who can get everclear and something less alcoholic, like vodka, could easily create 70% etoh.