How would you remove the THC through Fractional distillation? I have done 3 passes & THC is still just over 4%?
How do you crystalize the THCa without crystalizing the CBD as well simultaneously??
2 Likes
You crystallize the cbd, not the thc. Thca will crystallize as will cbd. Thc will not. I’m not clear on cbda. I believe it will crystalize, but have not seen it first hand
After three passes through your spd there should be no thca. Only thc and cbd. Only one of those will crystallize.
more theoretical plates (packing) might help…
3 Likes
Ok, is there a way to remove the from my Distillate without Crystalizing???
Chromatography?
3 Likes
Are you familiar with this method? Or can you point me in the right direction??
I appreciate any help & advice!
3 Likes
I’ve done a fair amount of chromatography, none with the cannabinoids yet.
why are you against crystallizing? it is the simplest solution.
5 Likes
You can invest $100k into a BRintruments spinning band system and retrofit it with a difussion pump. I believe the high separation ability coupled with ultra-deep vac will allow you to separate the two, however it won’t be a perfect separation and you will need to start with highly purified material as Cannabinoids tend to pull each other up with azetropic bonds and some contamination is inevitable.
And for everyone who is about to say it’s not possible, consider the fact that CBD will not distill and carry over into the condenser if the head (vapor temp) is too cold - IE 155-157°C (which is the boiling point of THC). Combine that with the amount of theoretical plates the BR offers and you may just get the result you want provided your able to acheive some deep-ass vac IE with a difussion-pump 
8 Likes
This is also not scalable and people work to seperate thc from cbd to sell it. Spinning bands can only get you so much material
2 Likes
Everything is scalable - I think your argument is that there is limited standard equipment with commercial availability for our industry which is true… But consider that even CTS KD30’s , 75’s, and 300’s didn’t exist until a need for them arose. You can get a BRintruments with a 22L Boiling flask - and here’s a pic of a medium level scaled-up version of what I’m talking about with the BR as well.
And if we are talking about massive scalability for separating compounds precisely by boiling point, the ultimate solution is a fractionation tower, not a wiped film:
Better yet - the ultimate Refinery goal would be to utilize multiple distillation methods in a tightly controlled closed-loop setting.
-cheers
17 Likes
now that says BIG oil!
2 Likes
I’d like @BR-Instrument to comment on this. We run a BR 9200 and just upgraded to 22L. We always run low vacuum (.05mmHG or lower) but we’ve never seen any meaningful way to separate THC from CBD there.
5 Likes
no, but the all knowing one can…
https://www.google.com/search?q=separating+THC+from+CBD+via+chromatography
ConfuseUs say: practice you your googlefu 
6 Likes
I guess my point is that it is not as nearly as scalable as the process I perform to remove thc from cbd crude.
Also these distillation units you have posted do not seperate compounds as close in boiling point as thc and cbd…
3 Likes
Its really concerning to me the amount of smart people in this thread and the prevelent wrong info it contains… molecular distillation is not suitable for separation of cannabinoids to the point of isolation.
It may be possible theoretically, but not one working model, not one valid test result has popped up. save yourself the trouble that countless companies ive consulted for have made. dont rely on distillation for separation at that level…
Nor can you rely on crystalization! you cannot crystallize 100% of a target molecule in an impure solution! you will only be able to crystallize a solution until your taget molecule falls under a 50% concentration in the remaining solution!
Can you remove the bulk of your cbd or thca through xtals? sure, nowhere near individual isolation of the mother liquid compounds.
Liquid partitioning seems promising, but untested.
Savve your money and r&d for liquid, superfluid, or centrifugal chroma
tl:DR chroma chroma chroma
14 Likes
I have to agree. Getting a super deep vacuum doesn’t change the distillation to separate THC and CBD, since molecular distillation (achieved with deep vacuum) is still based on molecular weights… which are the same for THC and CBD. One might be able to segregate the 2 using selective media in the distillation column, but that is fractional distillation more dependent on boiling point, using a selective material to split the boiling points further apart. It is very similar to chromatography, in action.
16 Likes
Ive always wondered about cannabinoid vapor flowing through a heated media column… had always come to the conclusion that it would just be a high energy-requiring bump trap… but youre saying that decent separation is feasible this way?
4 Likes
Hypothetically, yes. Even the ethanol:water azeotrope can be broken significantly with the right media and careful distillation, like ceramic raschig rings. Since the strongest force between the CBD and THC is the hydrogen bonding, and since CBD has 2 OH versus THC’s 1 OH, it is possible that ceramic rings would aid separation in cannabinoid distillation, too. However, because fractionation typically requires a longer column, the separation in a short path may not be sufficient. Worth a shot, though.
11 Likes
interesting, but as for a tightly packed column of silica/ alumina type adsorbant? that would be problematic as far as reflux goes but an interesting take
2 Likes
I would still recommend getting as deep a vacuum as possible, just to get the b.p. as low as possible, making a longer packed column feasible. The local pressure in the column will still be fractional level, even if the vacuum is strong enough to get b.p. down to 150°C.
Also, if you buy ceramic rings, make sure you wash them and check through them for contaminants and bits of detritus (especially metal) from the kiln! They can be surprisingly filthy.
4 Likes
Yeah, I am not recommending a powder packed column, as would be used in chromatography. Most efficient would be a structured packing that perfectly fits the column, but any random packing should be rather chunky, too.
5 Likes