This is the guy i was talking about who still got red coloration even after significant purification. he had great videos showing all of these steps until youtube took them down.
1 Like
I havenāt done that no, but that would be a cool setup for when the diffusion pump comes online.
4 Likes
It basically works like a wfe setup except the center condenser is set to an extremely low temp. The sharp gradient of temps can act like a magnet for anything that wants to leave the surface of the liquid. Looks cool. Scaling it up would be wfe though I guessā¦ unless you made a heatable tray with multiple stir bars and a lid that was much the same shapeā¦ either way cool experiment.
1 Like
maybe using ultrasonics to cause agitation instead of stir bars. that might make it easier to scale up without changing the geometry very much.
2 Likes
I like the idea of temp gradients for this stuff.
I think a long horizontal train of distillation bulbs, maybe even a train of distillation bump traps would provide excellent seperation resolution. If you put a spherical heating mantle on each bulb in the train then you could control the temperature individually as a gradient.
If each was a bump trap especially and you had say four of these in a line then you could dial in each bulb for the fraction you want. The final bulb would be chilled instead of heated and serve as a vapor trap (sort of).
I do all my terp seps now horizontally because it keeps the temp down and just grams of medicine not ounces. So the small bulbs work fine for me. Bump traps though can be pretty big. Not sure how you would harvest out of those?
What do you think?
1 Like
I went so deep on sublimation last night because of youā¦ It scales up for sure. Iāll organize my thoughts and notes and respond in full
2 Likes
Pretty much everything I would have said has already been said by @Beaker and @anon42519203 . Although this is not a sublimation (direct solid to gas phase) process, since it is a stirred liquid being evaporated to gas phase, it may be considered a ādepositionā process if the gas goes directly to solid phase upon contact with the cold surface. Whether it is truly deposition or not does not really matter, since the beauty of this lies in the increase of the mean free path (MFP), the straight line path a molecule or particle is free to travel without collision, determined by statistical math in quantum dynamics, to about 100mm at this level of vacuum (7.5 x 10E-4). Therefore, with a hot liquid interfacial surface to cold deposition surface distance of only about 1 inch (25.4mm) this is truly molecular distillationā¦ the MFP can be considered infinite within the bounds of that 1" space. 
7 Likes
The terminology becomes confusing the way this device is pressed into service so since the unit is termed a cryogenic sublimation apparatus I use the term sublimation for this process when a sublimator device is used. It facilitates communication. I am not that bright lolz so I have always considered any transition that skips the liquid phase to be sublimation either from a gas or to a gas. I graduated as a White Buffalo (Madras Oregon) with a D- average lolz so keep that in mind too lolz.
Then I did something REALLY smart and joined the Marine Corpsā¦not the brightest candle on the cake, eh? 
Good insights on terminology. You clearly understand what is happening at those pressures or rather complete lack of pressure. Thanks for weighing in.
2 Likes
@Beaker , you can think of the bump traps as a larger scale version of a Snyder column, but generally with stuff this heavy, we only use one inline before curving out and down for the distillation. I love the idea of multiple controlled temperature zones, and I have been wanting to do that with both cold traps and with boilers for quite some time. Just always too many other irons in the fire. I would love to see you do it, though, and I can help with the parameters!
3 Likes
I have not pursued the idea because it would take multiple PID controls and I donāt want to fiddle with that really. It becomes cumbersome for my lab table. Plus there is always R&D time to dial stuff in and so I have set it aside. Running in horizontal mode as I do sort of does it all really anyway. By this I mean that once the first fraction comes across horizontally then that bulb is removed and the boiling flask slid over to meet the next one for the next fraction.
This means very little cross contamination compared to traditional distillation because the uptake path and condensate path are removed from the system when the bulb is removed. At such low quantities this is workable though anymore I stop the horizontal kugelrohr run after terps are depleted from the boil. I can carry out distillation at 135C boiling puddle temp in the horizontal rig and get great results but not nearly the purity of the sublimator so I just switched to that. I perceive a horizontal rig for a gradient run to be a more precise choice because you are not dealing then with a thermal stack (necessary for vertical seperation) and each seperate cell should be able to dial in the temperature more accurately but it is only a hunch.
2 Likes
Agreed. Same issues here. I like a sublimator for small scale purification, for sure. It works especially well with DMT. 
5 Likes
@Beaker You are clearly a brilliant tinkerer, and I mean no disrespect at all in my correction of your terminology. Blame it on my autism! I do that so you and others will have the proper terms for future reference when searching the web for information, and in talking about it with fellow scientists like me. I know what you meant and why you used the term sublimation, but I wanted to give you the opposite term that goes along with it, deposition, to expand your awareness and save you from any later frustration or confusion in searching for information on the subject.
Navy, here, btwā¦ and an equally terrible decision in an effort to get money for college.
14 Likes
O shit someones interested!
1 Like
I like your idea about a tray to scale up. The top just a flat stainless steel lid to hold dry ice. The lid on top of a 1ā deep stainless steel tray. A flat seal like viton cut to shape. Fill with stainless steel ball bearings just enough they have some room to move around on the bottom. Just one layer of maybe Ā¼ stainless steel ball bearings.
Then heat the unit bottom and install a plate agitator of some sort. A continuous duty orbital sander coupled to the unit would do it or maybe a rocking table. Then monitor temp and pressure. Keep the lid cold and at Ā¾ of one micron and 135C exactly as measured on the side of the boiling tray then give it 30 minutes.
Break vacuum. Harvest. Replace lid. Keep repeating and at some point the collected compound gets dark or just stops. A pot the diameter of a pressure cooker but one inch deep would be capable refining a lot of compound this way I think.
3 Likes
Just a bump to see if youāve had the chance to organize your thoughts and notes on actual sublimation of cannabinoids. Thanks.
@pangea I think this would best be defined as molecular distillation of cannabinoids without a wiped filmā¦ in other words, extremely high (deep) vacuum and an extremely short path from evaporator to condenser. It is a deposition (rapid gas to solid condensation), but not a sublimation, as cannabinoids are not typical solids in the first place and this does not convert solid directly to gas.
1 Like
Thanks, I understand. I am just more curious about actual sublimation more for theory than anything practical.
I was thinking more what if we kept pushing the limits, @beakers going down to 0.75micron and evaporating at 120c. What happens if pushed to below decarb temps, what happens to THCA when it sublimates? Does it lose its carboxyl group?
1 Like
@pangea Naturally, THCa would sublimate as THCa and not lose its acid group, if that were possible. In small quantities, I am certain it is possible. In bulk, probably way more difficult unless some kind of thermal protecting reactant/additive were used.
2 Likes
$5 says you end up playing with vacuum depositionā¦
3 Likes
This is the first pass run being harvested. It is exceptionally clear for a first pass owing to a DCVC run first on dewaxed crude. The cold finger went back into the boiling flask to collect the final few grams of cannabinoid. The black tar is cleaned from the flask and discarded. All harvested crude is stirred together and pulled up into a biscuit under vacuum. First run is plagued with odor and doing this gives it time to air out a bit plus it looks cool.
Look close at the right edge of the white biscuit. You will see a part of the compound that was not stirred and can be compared to how much it expands when it is stirred to introduce air pockets.
The next step is to run this med again through the sublimator then after that a DCVC liquid chromatography run, then a final run through the sublimator. This will place purity at or near absolute. When the med is pure I can set the thermostat on my Vapir One vaporizer as low as 300F to get a good bag of vapor. Settings higher than 315F introduce a noticeable change in flavor and some throat burn which becomes very evident at 345F and above on this vaporizer. The compound changes at those temps. A setting of 400F produces a dense almost liquid cloud with a lot of throat burn and an enormous head and body rush. Very deep high. At times itās what I want but seldom.The residue left is very dark brown after vaping but of course no wax or mess at all.
5 Likes