The link is too long, can you provide a tiny URL?
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Better?
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Yep that works, thx!
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Good paper but with regards to full scale production of THC-free CBD distillate there isn’t anything there that would appear to be any more scalable than any other method of chromatography. Unless I’m missing something.
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I have been told there is a method much better than chromatography by a company making it. They paid for the proprietary SOP’s though
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Decarb the crude fully, then dissolve in your favorite alkane solvent (pentane, Hexane, Heptane). Do several flushes with a highly caustic brine (spike your salt water with sodium hydroxide to acheive a pH of 12+). Bring the solution back to neutral by flushing with distilled water and verify that neutralization has taken place or you will have isomerization issues later. Also make sure you dry out your suspension with a dessicant (mol sieve like Cbeads) prior to recovering your solvent.
The reason this works is the kpa of THC is 10.6 - we are essentially making it water soluble by exposing it to a pH of >10.6 - THC levels are very low in your Hemp-Based extract and after a few rinses we should have a remainder of mostly CBD + other minor cannabinoids.
Save all your water if you care to neutralize and extract the THC from the byproduct 
Cheers.
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I think we have a winner! thank you @Deleted
while not technically “crude”, the above product is neither an “isolate” nor a “distillate”, and although it’s going to be missing a few components other than just the THC, it is certainly going to have the general spectrum one would expect from “THC free crude”.
As a bonus, I’m wrong again, which should mean I’ve learned something.
Which would be way more satisfying if it was the first time I’d heard that trick…
Doh!
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Looks like I need a bigger sep funnel. Is there an ideal solvent to crude ratio? Or will just enough solvent to dissolve the extract do?
I can’t find any real data with a quick search. Does anyone have a good source for the pKa’s of the neutral cannabinoid phenols? I would have guessed that CBD has pKa’s similar to resorcinol, 9.32 and 9.81.
I literally cannot find where my glassware has been moved
Pubchem?
Why doesn’t the CBD become water soluble as well?
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What is the pKa of CBD?
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Both your cbd and thc would be deprotonted under those basic conditions. This deprotonation is what aids in increased water solubility. Can you explain why you think thc will remain in the water layer and your cbd will not.
Cbd would have two free alkoxides and thc would only have one which would mean if both alcohols are deprotonated on cbd it would be more readily dissolved in water over thc.
For all, yes the pka of the phenolic proton is around 10 (the same as other phenol protons).
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So, then this could theoretically work with minor adjustments. Bring to ph of 9.5-10, do your pulls, and neutralize the solution to bring out CBD, leaving THC in your organic layer.
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I think this is a better experiment unless i am missing something. The henderssen hasselback
Equation could determine your set point of ph and adjust the experiment accordingly.
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Even deprotanated the solubility of both THC and CBD are quite low. You will lose more CBD than THC to the aqueous wash. Since the THC level in the organic phase is much lower to begin with, you will still be left with a high concentration of CBD in the organic phase, by the time that you lower the THC concentration of your crude to acceptable levels. It will take multiple washes to get the THC low enough and this method might be better done with a counter current distribution. The biggest problems you are going to run into are emulsions forming at the high pHs. Unless your crude is already impeccable clean, there are going to the compounds with similar pKas to CBD and THC that are going to act as soaps. Also be sure to have good oxygen and temperature control. If you introduce too much oxygen, you are going to be essentially running a Beem test. You’ll turn the CBD in to a deep violet quinone.
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I have a few pounds of hemp I’ll be extracting as soon as I get my ethanol. I’ll play with these methods after cleaning the crude thoroughly and report back on the results. Hoping someone beats me to it, because between waiting for my solvent and lab testing, this could take a few weeks. I’m really wishing I majored in chemistry instead of getting a useless sociology degree. 
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I just wanted to add this educational video for those of us without a chemistry background to get a better understanding of what is being discussed using these LL extraction methods mentioned above.
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