50/50 Heptane/Ethanol Extraction To Enable Better CRC

I’ve been trying to help a friend do CRC techniques for ethanol shatter. Haven’t actually seen his gear, just talking to him on the phone. A young chemical engineer buddy of mine and I theorized that maybe mixing his ethanol 50/50 with heptane might be the move forward.

Ethanol doesn’t respond to CRC techniques very well. But there has been some talk on other threads that Heptane does. So in order to make a more efficient system, maybe mixing an aggresive solvent like ethanol, with a less polar solvent that is not super toxic like Heptane would make a bit of sense. If at the 50/50 ratio, they would not become an azeotrope, it seems possible that the slurry could be rotovaped, the ethanol coming off in the first fraction, leaving the heptane to be run through media to increase results. This would leave less time for solvent recovery (Which is his bottleneck) and potentially allow for better clarity in his shatter.

Anybody care to poke some hole in this? I would love to move forward and share some results.

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Ethanol doesnt respond well to crc techniques because most of the separation occurring in a crc powder stack is happening in the silica gel and/or magsil which are both very polar media.

The reason the process happens to work so well with alkanes lies in the fact that alkanes are non polar and the adsorptive medias are polar, this is relevant because as you pass the non polar solution thru your media the more polar compounds that are dissolved in your solution would rather stick around and hang out with the silica gel for a longer amount of time than the cannabinoids.

I hear tell that ethanol and bentonite can make an effective combo for color remediation with the aid of sonication. Not the case with silica gel as far as i know.


This has been discussed and the since you have to heat your product to at least 120c to make sure there are no residuals that won’t work for shatter only for distillate.

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Thank you @ScoobyDoobie for the response…

My question, is there a solvent mixer the would be effective for his color remediation goals that could be evaporated off in fractions and yet be responsive to the filtration media techniques(and also not have tons of harmful vapors in his shop). my thinking was that the ethanol could be evaporated off, leaving the heptane slurry to be run through a filtration media regime, thus cutting out the need to evaporate two solvents completely off. @Renchi could you point me to that thread? He is already getting stable shatter by purging in the rotovape, just dark

Actually, that makes a bit of sense, he has no test results for them, being that it’s “that” type of lab…

And it was 98c, not 120. Regardless it would start to convert thca to thc.

Edit: click the screenshot to get to the info.

Could you define this a little better?

I don’t see what benefit this will have over just using straight heptane to begin with.


I would think evaporating the ethanol and then using pentane would be the way to go.

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Sorry… Is there a solvent or mixture of solvents that can be run through a ethanol system where CRC techniques could be effectively applied, and shatter can be produced? He can’t afford more equipment at the moment and with the vaping scare wiping out his distillate sales, I’m just trying to keep him alive…

Really good point. Do you know of any potential problems with heptane in Ethanol systems?

Thank you!

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You may need to change gaskets. Check the material compatibility charts

As far as i know, adding ethanol to your heptane will decrease rentention times for the pigments your trying to remove. The decrease in retention will be directly proportional to the amount of ethanol in the mixture.

Ethanol will likely not be able to do what you want it to, but maybe the less polar alcohols like propyl alcohol would work better in this application although i kinda doubt it. It just comes down to what the pigments would rather stick to, and if alcohol is in the mix they would rather stick with alcohol than the media.

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Thank you all for the advice… I don’t think I’ll recommend this course of action and I appreciate the advice to save my friends their limited resources.

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I mean… Try it out and report back!

How does the vapor pressure and boiling points interact? Do we know the ethanol and heptane won’t evaporate together? It seems to be the case that high boiling point terpenes end up in my lower boiling point Ethanol despite the temperature in the system not getting up to the bp of the ethanol.

I’d also think instead of a “best of both worlds” for undesirable pickup, I would think you’d actually have a broader spectrum of non-polar undesireables than a pure ethanol wash. And more Chlorophyll than a pure heptane wash (though these things are certainly temperature dependant).

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The move forward is to extract in heptane and then winterize in alcohol and then lle back into heptane. Then crc. Duh. (Billie eilish voice)


I think the move is gonna be to first pass propane for Terps, second pass butane for shatter, badder etc, and third pass ethanol for distillation


Extract wet plants with hexane/heptane; straight into LLE with methanol/water; filter through adsorbents for decolorization; membrane filter (or also adsorbents) for fats; remove heptane and distill.


So sonicate with bentonite in the mixture?