Ethanol Azeotropes - Attn: EtOH cannabis extractors!


I’m thinking good ol clean ethanol



The biggest pitfall I can see is workplace safety. Proper PPE might have to include respirators and/or adequate ventilation to limit exposure to fumes, as well as gloves and aprons to limit skin exposure.



Methanol is cheaper than 99%iso

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In the netherlands we have 5% denatured ethanol with methanol
IT pulls slightly more green at ultra cold temps
Other than that iT works fine
I also use pure 99.5 % methanol
Once below -70C i don t notice much diffrance other than a slight green heu
On long residance times
IT saves a lot of evaporation time in My post Distillate clean up sop s
Where i Need a oil
/ methanol solution



So methanol is easily recoverable and really cheap. It’s somewhat polar and somewhat non polar and mixes with things as diverse as alkanes and water. It’s easy to dry, and much less polar when dry than when a little wet. This is probably Rogue lab above sees more green.

If ethanol is much easier to work with regulation wise, and the profit is high enough the chemical cost isn’t significant, ethanol makes sense for sure.

In a situation where chemicals are a pain in the ass, methanol is very easy to recover back to pristine condition and low cost.

And it would only take a tiny bit of ethanol in the extract at the end to be sure the methanol was gone.

Ethanol is a lot more toxic than we give it credit for, not to say that methanol isn’t much more toxic, but in reality ethanol greatly increases the risk of cancer and methanol isn’t any more dangerous to be around, assuming you don’t ingest it. I’d never fear to wash my hands with it, even if it’s a taboo topic, any more than I’d be afraid to wash my hands in ethanol.

Drinking a few beers a year is arguably more dangerous in actuality than working with methanol using reasonable but normal safety protocol.



To be fair, methanol is actually present in very low concentrations in almost all alcoholic beverages as well. Especially in ciders and wines. For what that’s worth.

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So extract with methonal add ethanol to the finish rotovap off? Does methanol have a bad smell or taste? What’s the max ppm?



Methanol tastes very much like alcohol. But don’t taste it!

Ethanol greatly reduces methanol toxicity.

Yeah you’d get most of the methanol gone, then add ethanol and remove the ethanol. You willbe left with whatever ppm ethanol you’d normally have.

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What would be a similar extraction and winterization sop look like with methanol?

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Interesting a minimal amount of ethanol. The methanol would be coming out the same proof after reclaim? And after you got tired of it you could dump it in the gas tank



Basically the methanol boils a bit lower than the ethanol so by the time any ethanol starts boiling the methanol is gone. It’s all heads in distillation. The methanol should be the same after you reclaim it, but in a humid area it may pick up some water which can be dried with magnesium sulfate easily. It does form some azeotropes, so if you add extra things, check them.



Basically pick up no more than ethanol would correct?



It’s much less likely and really only happens in swampy air. It’s also easily removed :).



Well I think I’m gonna giver a shot. Are you enjoying the forum?

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Methanol doesn t like Waxes Wich is a great plus

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Well, I see this thread went completely off the rails in a hurry, and most of the questions asked were already answered in the op. For those worried about the expense of solvent loss and looking to go super cheap on solvent for lack of tighter recovery practices, I strongly suggest looking up the hazards of chronic methanol exposure. The concerns I have with it are for the workers more than the consumers, at least when it comes to properly prepared and analyzed products.



Thank you for your post, it is nice to find corresponding evidence.

We have recently completed research on the benefits and drawbacks of 5000lb target scale Heptane extractions, mainly to harvest fresh, reap the benefits of chemical drying, avoid chlorophyll pickup etc etc. So we came to the same conclusion on Heptane denaturing, thankfully we reached this conclusion at bench scale! lol

Now the question becomes, how to efficiently maintain the 95% and how do we fight the terps making bonds during the continuous in line 190 reproof reduce recycle process required to feed the beast ?

I wonder if the answer is in the EToH binary …



So yeah I’m trusting that all of you do learn about ventilation. I prefer to work in a lab with proper ventilation, for sure. Fume cupboards are great for really toxic stuff, but for methanol and hexane etc I would design the lab so that the whole lab was well ventilated. This is not inherently different than the ventilation in a weed grow room, you want negative pressure in the room, the door trying to close. This is good enough for most chemistry that’s not exceptionally poisonous. Methanol exposure is also very low with proper handling. It probably would take me a bit of time I don’t have atm to think of all the ways methanol could get in the air… so it’s best just to make sure there is ventilation. Alcohols are also pretty terrifying in terms of their flammability when gas phase also; methanol is not worse than ethanol in this regard but if you are evaporating lots of ethanol without air flow— open flame is terrifying.

@champone it’s not often that there is a forum with so much life and discovery. These periods seem always finite and the sort of thing legends later are made of



Yeah I just buy those 2299 cfm fans w ducting 136 bucks on amazon pretty easy. Getting me some methanol ol son

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@Photon_noir what about the “chonk” aka polymerized sugars being seen/formed in this heptane denatured ethanol? Would this be eliminated going to straight 200 proof ethanol? I believe its the heptane/water forming bonds with sugars “chaining” them under heat