You do realize theyre basically doing chromatography with silica in there? They even said silica is the key to water clear shatter and without it you cant make it. I wouldnt consider chromatography a “scrub”. If it is then yes i can make water clear ethanol crude if i “scrub” with silica in a column lol theres a reason why theyre now looking into the PR abilities of the CRC, because its chromatography more or less
2 Likes
You think you are going to get good separation running normal phase chromatography with a polar solvent? I would like to see you do it. Reverse phase media is a thing for a reason. In any case if you look at the EHO thread and see plenty of examples of people running their ethanol through silica with less than impressive results.
4 Likes
Woot woot ^
Also i would think bottom filling a column with a non polar and draining out of the top would work better since aqueous phase is heavier. But hey what do i know
5 Likes
Anyway that is the least important point I was trying to make. Using scrubs is like 1% of what I was trying to start a discussion on.
What everyone is really looking for is a way not have waxes while avoiding changing solvent. Right now everyone has picked cryo ethanol as the best way to do this, but I would like us to think outside the box. I don’t think cryo is perfect and I think there must be better solutions out there. For one, cryo is an energy hog, and two, water pickup will always be an ongoing problem.
I flagged nanofiltration as a way to remove waxes because I saw trial data from ecosce and evonik where they both demonstrated and quantified wax removal with membranes, and because the transmittance rates through a membrane with hexane are very very high. Like well over 1000 L/hr on a ~250k unit. You can choose to doubt whether it works. Within this year these will be pretty widely diffused, and i’ll either look smart or I won’t.
But that is still not the point. There could be other ways to remove waxes. At the indo expo I saw a seminar where a man said he had got good results removing waxes via direct centrifugation of the crude oil. In another thread on here, people are hard at work trying to use adsorbents to dewax in a nonpolar solvent. Yet again, in another thread people discussed room temperature methanol as an extraction solvent (which removes need for cryo, but water pickup would still be an issue).
What i’m really trying to discuss is methods for removing wax besides cryo ethanol. I suggest membranes because I really believe they are the most effective technology in this area. But i’d love to hear other ideas too.
4 Likes
You said no one can get as good of results “scrubbing” with silica as in the CRC thread, youre not scrubbing first of all youre doing chromatography so maybe if youd actually use proper terminology we wouldnt have to figure out what youre trying to say.
Tell me what your definition of scrubbing is that would allow a column of bleaching earth to count, but not a column of silica. The definition of chromatography allows any solid with any affinity for a compound to be used as the stationary phase. Furthermore, chromatography in chemistry is generally applied to a technique that elutes every compound through the media in bands. However in this case people do not want the color compounds to elute; they want them to be 100% retained by the media, which makes this decidedly more of a adsorption scrub than a chromatography run.
There is nothing magical about silica. Silica is a convenient adsorbent to use for normal phase chromatography. What you’re describing isn’t even normal phase. Normal phase uses a nonpolar solvent with a polar stationary phase (silica). You are suggesting using a polar solvent with a polar phase. If you knew how chromatography works you would see that’s not a winning combination.
7 Likes
Scrubbing isn’t a technical chemistry term. People use it informally here to mean purification by adsorption. Silica is an adsorbent. Silica in a column is also an adsorbent. It could be used for chromatography. Or you could run everything through it and hope it just completely blocks the bad stuff, in which case, it’s being used as an adsorbent only.
8 Likes
This is going to keep me up all night tonight, and makes me want to see if I can convince my business partners to spend some more R&D money.
This kind of system would be a bit of a bother from a regulatory perspective, but really no more so than any other hydrocarbon based system.
To go from ethanol to heptane/hexane you shouldn’t need to change much actually, many of the common materials that are used for ethanol are also reasonably resistant to alkanes. I’d probably add in a nitrogen blanketing system, and some other minor modifications, but not much else off the top of my head.
3 Likes
Don’t these nanofiltration membrane systems still leave some solvent in with the separated oil? I’ve seen talk of 1:1 ish ratios on the output. If so, you’d still need some sort of other system for removing the final portion of solvent. And with heptane having an even higher BP than ethanol you’re likely to lose even more terps than with a standard ethanol extraction.
4 Likes
Yeah, you need either a secondary evaporator or the direct crystallization approach. As far as BP, hexane would be better.
3 Likes
Im with ya on the membranes. I too have seen the data, and will get to experience first hand in the next month or so, and will be comparing to centrifugal separation. I’m betting neither will be “perfect”, but confident that one or the other will be better than the traditional cold sep tek we’ve all been doing for yrs.
5 Likes
Tell me a little about centrifugal separation. I was just talking to someone who mentioned it.
Centrifugal seperation works Ok on polishing of extract
I have done Some test runs with ethanol extracted cbd oil and Brine water ph swing
So more of a LLE function
1 Like
Hexane has been used as a solvent in large scale industrial oil extractions for years. It’s highly efficient.
9 Likes
Yes. There’s very large continuous extraction systems for it already available, could be converted over with little effort. Follow up with a screw centrifuge for further solvent recovery into membranes and cycling hexane back and you’re well on your way to a fully continuous start to finish operation.
3 Likes
Could you send pentane through a membrane as fast as heptane?
If so wouldnt that be the better choice for solvent since it would take less energy to remove.
1 Like
I don’t have any data on that, but it might even go faster, because it’s viscosity is lower.
1 Like
Could probably just go straight to crystallization after extraction. Even if the membrane cant catch all the waxes im pretty sure solubility of cannabinoids in pentane is lower than other alkanes.
Someone om this forum said thats the reason the cold crash technique works so well in pentane when compared to hexane.
When temps drop pentane precipitates cannabinoids from the solution faster than other alkanes would at the same temp.
3 Likes
Yeah. Conversely the pentane is also got a lower solvency than hep/hex for the cannabanoids. So I can definitely foresee extraction efficiency as the loss with that solvent.
2 Likes
But if we’re talking about a massive system then solvent volume wont be an issue. It might make sense to just adjust the solvent volume per kg of material based on the degree of cannabinoid retention when compared to hexane or heptane at a given temperature.
The amount would probably be almost unnoticeable.
3 Likes