Inline Winterization of subcritical CO2 w/ Alumina

Will the lipids have an affinity for alumina while in a liquid CO2 solution?

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From a polarity perspective…unlikely.
From a particle size distribution/filtration perspective…perhaps.
Suggested mod: use a nonpolar adsorbant and use a 10 parts co2: 1 part etoh solution for the mobile phase. Most likely will still need to separate fractions and flush.

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the process seems analogous to normal phase chromatography, where the aluminum is more polar and the subcritical co2 less so, waxes being attracted more to the non-polar solvent (sub-critical co2)
I think @Dirteagle may have a point from particle size distribution although Ive used DE inline previously with supercritical co2 but didnt seem to retain the plant lipids

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Regulations limiting inline etoh are a problem

You should have pretty good selectivity with subcritical co2 (vary P&T) to the point that most of the lipids are retained in the biomass. You’ll sacrifice yield for less downstream processing.

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Most being the key operative… Investigating the potential of not ever having to use a solvent to fully winterize.

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Aw come on, CO2 is still a solvent. :wink:

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Cannabinoids dissolve in CO2?

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Yes, co2 dissolves in liquid state. I would look at KAVA extraction and filtering.
Kavalactones are extracted. The infamous Polynesian kava kava drink.
I have some of the extract and some of the high potency powder.
Co2 was never on my radar for cannabis but I like where you’re headed. Definitely makes some nice crude.

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I’m getting pricing and should have some inventory up soon for high pressure applications for filtering — if you end up going the route of using adsorbents. I look at the build
for replacements. My first thought on this though is why not use a membrane? We can definitely do a build at indofabs. I didn’t think about this application for co2, but this would be cool.
That fits into the program so if they/you wanna do that…

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When you look at the big picture it’s still hard to know what is gonna be the “best” way. If membrane filtration is added AND the selective sorbents that are custom cut for thc are added, you could achieve t-free crude that would Be beautiful.
But if thc goes legal then who cares.
If the sorbents are too costly or take too long and the pressure causes channeling or whatever other issues…we have in-line ethanol remediation NOW that is way ahead of reverse phase, multi-solvent, etc etc.
so then the thc remediation become another issue with the co2 program.
We are also getting close to full cannabinoid separation sĂł where does co2 fit in to that? The pressure is too high I think.
Right now crude is aimed at $400-500/liter
I know people are getting more for some of the co2 that looks like disti but from what I gathered their COGs were about $125/L
There’s still a whole lot of profit room
SĂł ya, even just making co2 crude would be good and no sugars right??
I think next year is gonna be another tech explosion

You mean thc dissolves in liquid co2?

I know CO2 can extract THC… But that doesn’t automatically make it a solvent.

Cbn:
https://pubs.acs.org/doi/pdf/10.1021/je100245n

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I couldn’t find anything from ACS or anyone regarding subcritical but I would think the co2 guys would know.
It’s supposed to dissolve the trichome membrane. I never thought of CO2 as a mechanical separation.

https://www.aiche.org/conferences/aiche-annual-meeting/2017/proceeding/paper/179a-solubiltiy-and-phase-equilibria-optimizing-processing-cannabinoids-and-terpenes-cannabis-and

I forgot about expanded ethanol co2 also.

This might Be useful
For CO2 folks
https://books.google.com/books?op=lookup&id=igcjBQAAQBAJ&continue=https://books.google.com/books%3Fid%3DigcjBQAAQBAJ%26pg%3DPA105%26lpg%3DPA105%26dq%3Dco2%2Bdissolves%2Btrichome%2Bmembrane%26source%3Dbl%26ots%3DCa72PZ4dd-%26sig%3DACfU3U0JfO4ViLCdiQzTy4kggLaaARXcfQ%26hl%3Den%26sa%3DX

I would work on a membrane system but I can’t go too far down the co2 rabbit hole until
I finish some other things first.

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Yep, they sure can, so can waxes, which is why CO2 is, so far, a somewhat poor solvent choice for cannabis. With a Waters machine the solution gets pushed through a steel micron filter.

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If you’d like to chat about it from an operator’s perspective feel free to reach out.

Someone from Vitalis contacted me last year after I dropped the CO2 Sauce pics, that’s who you’re working with right?

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As far as I “work” with any of the GLG affiliates, yes

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In the context of sub and supercritical extraction, Yea sub/supercrit CO2 is definitely a solvent, although a poor one for cannabinoids, and furthermore its a solvent that is tunable meaning the polarity can be manipulated across various pressures/temperatures. At extraction pressure of ~300 bar & 60 C maybe its a similar polarity to acetone or methanol? (I have no data for this) The pressure differential from extraction vessel to separator vessel causes that shift in polarity casuing cannabinoids or other fractions to drop out of solution and into the separator at some threshold pressure value

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From my understanding magnesium silicate is better suited for winterization, the magnesium molecule allows the phosphorous molecules from the phospholipids to bind easily. They use magnesium silicate in pretty much every vegetable oil facility for room temp dewaxing, but they are usually using ethanol as the mobile. Don’t know how it would apply to CO2. If you haven’t already you should read bleaching and purifying fats and oils second edition from the american oil chemist society. It’s about fifty bucks on amazon.

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