A (likely) unsolvable problem with ethanol extraction (keep them terps!)

Hey friends,

I’m currently in the process of starting up my ethanol shatter extraction, and I’m bumping into what’s (likely) just a problem with the nature of the solvent.

What I’m referring of course is the azeotrope made by ethanol and the turpenes at a similar boiling point to the ethanol. I’ve noticed that the ethanol afterwards smells and tastes delightful lol, on account of all the turps that are in there and not in my shatter!

I’m curious if anyone has a remedy for this? If there’s something that would have a high affinity for turpenes to pull them out of the ethanol?

I know the obvious answer to this question is remove them beforehand (I’m building my co2 extractor but it takes time!). Or use a solvent with a lower boiling point!

I’m considering distilling all my solvent under vacuum and create a true fracking column to separate by boiling point (this seems like a bunch of work). If I kept it low enough I feel like I’d have some potential for success?

I’m assuming I’ve either hit a wall or a plateau in my thought process. I figure I’d check in to see if this is something I can even try tackling or if it’s just a fools errand even thinking about it. (I just wanna make the best S^#&!)


It might be that another solvent is the right answer, but I suspect modifying the one we have should also be explored. I’ve heard talk of altering their solubility in ethanol using salts or CO2 (CXE).

Both are currently out of my realm of expertise, but I’ve certainly manipulated the solubility of DNA in alcohol/salt vs aqueous environment to my advantage in the past.

So yeah, best I’ve currently got is grab them first. somehow.

I don’t have any first hand experience, but vac assisted steam distillation appears to be the most obvious route. liquid CO2 also seems like an effective if somewhat expensive route.


Really cold butane or other similar forms? Or are you not regulated for volatiles?

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Not regulated for SFA :stuck_out_tongue: so i could certainly experiment.
The building I’m renovating will have high hazard compliancy so I could certainly run whatever I wanted provided I got a couple engineers in here to adjust my plans.

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You could put together a multi use system. One capable of counter current cold etoh and use it with volatile hydrocarbons for when you want to produce a shatter with a high terpene percentage. I can get up to (so far) 5.8% terpene on a trim/popcorn run with less than a 100ppm of residuals for shatter. For live resin I have pushed up to 12%.


I have been playing with
Revursed osmosis on ethanol / oil to recover the ethanol that has not given Any positieve results yet ( mainly for. The equipment beeing used )
But i did notice that is does take out terps
Have No data on how Many etc etc
Out of Hot distilled etho
So hot distilled etho in on one end cleaner etho out on. The other end and terps and god knows what else stay on the other side
IT was to little to pour out and i treu iT out
But that might be a way to recover

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I have 10 gallons of “terp shine”. What a few of my buddies and myself call it.


Ethanol azeotropes are hard to break… this has always been my issue with EtOH extraction.

Pull them first with hydrocarbons or CO2, otherwise you’re dipping into lots of weird liquid to liquid transfers with hazardous chemicals and a myriad of solvents.


If you want to keep the terps, you need to pull them from the ethanol in some way. This is a non-trivial problem but similar problems have been solved in other industries.


D̶o̶e̶s̶ ̶b̶u̶t̶a̶n̶e̶ ̶h̶a̶v̶e̶ ̶l̶o̶w̶ ̶a̶f̶f̶i̶n̶i̶t̶y̶ ̶f̶o̶r̶ ̶c̶b̶d̶?̶ ̶C̶o̶u̶l̶d̶ ̶o̶n̶e̶ ̶d̶o̶ ̶a̶ ̶b̶u̶t̶a̶n̶e̶ ̶e̶x̶t̶r̶a̶c̶t̶i̶o̶n̶ ̶p̶r̶i̶o̶r̶ ̶t̶o̶ ̶e̶t̶h̶a̶n̶o̶l̶ ̶e̶x̶t̶r̶a̶c̶t̶i̶o̶n̶ ̶t̶o̶ ̶r̶e̶m̶o̶v̶e̶ ̶t̶h̶e̶ ̶t̶e̶r̶p̶e̶n̶e̶s̶ ̶a̶n̶d̶ ̶t̶h̶c̶ ̶f̶i̶r̶s̶t̶?̶ ̶W̶o̶u̶l̶d̶ ̶t̶h̶a̶t̶ ̶m̶a̶k̶e̶ ̶e̶t̶h̶a̶n̶o̶l̶ ̶e̶x̶t̶r̶a̶c̶t̶i̶o̶n̶ ̶h̶a̶r̶d̶e̶r̶?̶ Never mind, this got answered, butane extracts CBD

Is it possible to make water hash with hemp? Would that make ethanol extraction easier?

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Any hints at how? Or just what’s been listed above?

If I get my process worked out and get my patent filed I’ll release the fundamentals to the community for non-commercial use. (Ie: feel free to use it for yourself, just don’t sell them) Not willing to say any more for free at the moment (am looking for funding/research partners though so if anyone has some cash burning a hole in their pocket feel free to ping me.)


Maybe a bunch of us smart kids (dont’ know if I should be included, but I’ve got a knack for a bunch of this stuff) can get together from all over and create ourselves a nice franchiseable extraction setup :stuck_out_tongue_winking_eye:


Pretty sure there are people here who would be interested in such a thing. And I like the franchise model idea.

I’ve already had a couple of offers to set up labs for people, I just don’t have the time. Startup life etc.


Steam distillation first to pull terps, followed by drying/decarb of wet material then EtOH?


extraction difficulty increases after steam distilation


Would you elaborate on that?

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Terpenes are your co solvents in ethanol extraction. Steam distilation adds water content to biomass and damages cells


I would guess that you are actually forming azeotrope with ethanol and water and the resulting steam is pushing out the terpenes. When you distill alcohol the water in solution essentially gets concentrated in the evaporating flask. This heavy water fraction is what I’m referring to. The ethanol will of course pull out terpenes with it, but there seems to be little interaction between the molecules in vapor phase. The water repels the terpenes and actually pushes them out with a much greater effect. So I would probably try and eliminate water where possible. Maybe create a solvent looping systems wherein the water is absorbed or separated in some fashion.


I was thinking (and have been told by others looking into the process) that you would dry and decarb the biomass after steam distillation. So minimal water left before ethanol. But I see you point that steam could break down the cellular structure and allow the internals to leak out. The same problem as too much mechanical sizing presumably. And possibly freezing. Is this really a big deal with cold QWET?

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