THC/CBD separation using short path


…because the whole point is the evaporation is coming from the thin film. :man_facepalming:

Yeah, I’m a little slow sometimes.


You can get a quick summation of how I met Sasha by reading the small chapter I wrote in the new Commemorative Edition Box set of Pihkal/Tihkal (pp. 414-416, Tihkal). Its fairly boring. I met him long after his ability to work in the lab had past. I raised a lot of money to help pay off his medical loans and made sure that his last days were spent at his home (instead of a hospital or some such awful place to die) surrounded by those that loved him.
I only did some very basic operations in the historic lab, helping the chemist that took over the lab clean it up and make it back into an operating lab, (or at least evict all the birds, squirrels, and rodents, lol).


I have no way really to tell what is or is not left behind in the boiling flask. Since I ask for extract with no CBD and normally get it I just would not have the experience to know. The compound I get jormally tests at zero CBD.

The only way to ascertain whether or not it is possible to separate the two in my sublimator apparatus would be to rig an experiement with known quantities of each and lab test before and after. Otherwise it is just guesssing. I have not yet seen videos of others running the low temps that I run or set up vacuum wise to pull down during operation. Separations that are pretty tough otherwise have a chance at these “gentle” distillation conditions to separate cleanly but then again it takes multiple runs through the rig because no distillation rejection rate is perfect. If you can hold an oil temp of 127°C, and the pressure at one micron, and keep the short path travel to just an inch or so (really a no path device because there is no glass path that the compound interacts with up to the point of collection) then you would have the ideal conditions to try this as an experiment but as for commercial applications it would be tough to scale.


The early kugelrohr was made from a windsheild wiper motor and a coffee pot, the seal only went 180* so it was possible to have a high vacuum connection that dident rotate.

kuglrohr.pdf (1.0 MB)


To be clear, Kugelrohrs are awesome!
Especially for a small producer, but also as an additional distillation apparatus.
For instance, if you have a small 2" WFMS as your only distillation equipment and you somehow break some glassware and it ends up in your beautiful distillate (or you even just think you might have! gotten it in there!!).
This is a big time eater, right?
Now you probably have to put it back into solution so you can filter it, then you’ll need to remove the solvent, probably via rotovaping. Then you’ll need to either re-distill to remove residual solvents, or put the material into a vac oven. I’ll let you do the math on the amount of time thats going to eat up at your lab. Most likey using equipment that should be processing new material, not reprocessing material that may have glass in it.


Now, if you built yourself a little kugelrohr set up, say with an old Buchi RE-120 motor, and a modified large stainless say, wort brewing pot from the brew shop slipped over the heating bath (Now made into a air bath).
Now get yourself some old-spinning 2L Kugelrohr glassware (including a “flying saucer bump trap”, you may need this made for you. I recommend Adams & Chittenden in Berkeley, CA. They are the scientific glassware pros for the western US and they have been for 30+years), two or three cold traps, a thermocouple probe and controller, hook it up to your vacuum system, and you’ve got an amazing set-up that can run material full of glass or whatever, no problem.
Plus when your not fixing your mistakes you can plumb it into a vacuum system and use it as a SPMS (short path molecular still) if you get a proper vac system that can pull below 10mTORR. The whole set up (minus the vacuum system) will probably coast you $2000-$3000.

I love having a Kugelrohr in my labs.


I’ve started a separate thread for more discussion of homemade Kugelrohrs and adjacent topics…

and also started a thread in response to the request above regarding Sasha…
here you go…
more to come


This is elliots new SPD 7 which essentially is meant to run so quickly because your fractionation (or lack there of, rather) doesnt have to fight any gravity. they also use nitrogen sweeping to carry any vaporized oil to the condenser quickly


Dosen’t that screw up the ability to “fractionate” ?


Yes it does, but fractionation is not the point of the spd7. I talked to Elliott at the MJ biz con this year about it and essentially its for 2nd pass only, and its just meant to fly through material with no fractionation. Think of it as a hyperefficient version of the Cold Finger unit @Beaker uses.

Almost no theoretical plates but just enough for quick separation.

I set this exact unit up at a facility in colorado. not the same model, the exact unit shown in this picture, my collegues bought it at the biz conference.

Im doing some work in Europe now, but ill be back in a few weeks and ill update you guys on how its workin.


And how about screwing the vacuum depth ?
Don t think iT s a good idea