Specifics for cbd spd

I am familiar with standard thc sbd. Temps, fractions, vac, cold traps etc.

My questions is what are the differences if you start with cbd crude from hemp?(And want a final product of just cbd)


Not a whole lot, boiling points will be close also.
Give it a go, it won’t be hard.


Define close.

it really depends on that young vacuum and the type of crude, but I usually see around 180ºC at 300 mtorr for my high CBD fractions.


Depends on how strong your vacuum is. The deeper the vacuum, the closer their boiling points are. less deep vacuum and the boiling points begin to separate, though not much. It will only be a degree or so different at ultra low vacuums, thus why its not really feasible to separate CBD and THC in a SPD


So, I understand that it’s not practical, or perhaps even possible to completely separate the two, but how close can you get? Are you able to start with something that has 62% CBD, 2%thc 2%cbg 2%cbc, for example and distill a compliant (.3% delta 9) product with spd? What parameters would you use if this was your goal? What’s the max boiling flask temp you would recommend to facilitate separation using weaker vacuum? Is there anyway you could denature or destroy the THC while keeping CBD intact? What would be the isomerization products of a batch like this if I tried refluxing with carbon? Thanks for the info

I think that trying to separate them via SPD or WFE is not really practically possible. You would have to have your temps low enough so that the CBD barely pops, which would be incredibly hard, and even still, since the boiling points are so close, the CBD will drag some THC up even if you were to get your temps perfect.

I think that the weaker vacuum idea is interesting, but you will start to run into other issues there, and the temps would be much higher. degredation would increase, and the ability to separate them would only be slightly better. Not to mention that the flow rate would be very slow if you are just barely popping the CBD.

Unfortunately, I do believe that CBD isomerizes just as easily if not easier than THC. You could possibly use T5 or carbon in the flask and get all the THC to isomerize, but the CBD would as well, leaving you with a mix of CBD/d8/d10/CBC/THC. Unless you are actively trying to create d8 I would avoid putting adsorbants into the boiling flask. A reflux at a lower temperature could isomerize just as much.

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Very interesting stuff, I think there could be a market for delta-8 and cbn especially. So do you think we could isomerize all the CBD and keep the reaction going until all the CBD and delta 9 was converted? I guess I’m asking, what would be left with if we cooked it long enough to get the delta9 converted to compliance levels. I’m guessing mostly denatured trash. But maybe some delta-8. I just had a thought, it would be more efficient to create delta 8 from CBD free extract, am I right?

CBD more easily isomerizes to delta8 than THC unfortunately. They will both isomerize if heated in an acidic environment, but I know that people who are trying to make delta8 often start with CBD distillate, and introduce an adsorbent to the boiling flask. The adsorbents commonly used all have acidic active sites, allowing for the cannabinoids that are interacting with the active site to isomerize.

The amount of isomerization depends on the apparent pH at the active sites, as well as how many sites there are (how much adsorbent is used). You can get lots of isomerization from as little as 1% adsorbent to oleoresin. If you were to reflux until the all the delta9 had been isomerized, you will start to get even more isomers. It’s not easy to test for these isomers, they like to show up at the same point that CBC appears on spectra, this causes extracts that have been isomerized to have higher CBC peaks.

Unfortunately there is no easy/open source/cheap way to remediate THC, it seems that Chromatography is the current most used and best way.

There are markets for delta8 and CBN, though the amount of random unidentifiable isomers that would appear along with the delta8 make it a bit undesireable in my opinion. Also, CBN is not an isomer of THC, so it is possible to have lots of isomerization and not make any extra CBN. Lots of people around here are interested in CBN, there are some other threads you can check out if you are interested in making it, though its not down pat yet.

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Awesome thanks for the info, you’ve convinced to buy a chromatography column and learn tlc/spectrometry. So not an isomer, but cbn is an oxidized or reduced product of which cannabinoids? I’m getting alot of contradictory info about that.

THC’s formula is C21H30O2, where as CBN is C21H26O2.
You can see that there are 4 less hydrogens on the CBN molecule, so yes, it is an oxidative degredation product.

I would ask some other members about chromatography for THC removal, I only use it for testing (HPLC), I am not sure if there are any non-expensive ways to remove THC, I know that a flash chromatography machine can cost some real money. maybe @Roguelab @Soxhlet @cyclopath could chime in and point you in the right direction?

I sure appreciate it, if you’re in the area stop by and we’ll burn one. I believe I’ll be able to afford a conventional column, but I’m not sure how to figure what dimensions I would want to get a profitable yield. That and perhaps a used spectrometer instead of tlc for better measurement.

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If you get a UV spectrophotometer, I would love to see your results. I was thinking of getting a cheap one to measure rough concentration in my CBN distillates very quickly and cheaply.


It’s near the top of my shopping list. If I can sell the kilo I’ve got for a good price. It could be soon

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