I collect the end product by pulling the cold finger. I dump the ice water into a tall SS cup then let thaw a bit at room temp. Then it peels off the glass pretty easy because the glass is cleaned with acetone first prior to use. I put it into a petri or onto a small mirror.
The bell jar vacuum is just on the same table because it is close to the vacuum barb.
You are right on the sequence I use as SOP. First boil in iso and pull through Büchner funnel to rid it of chlorophyl and wax. Then optionally pull it though a DCVC column if geared up for it and supplied. It saves considerable time later.
Then the horizontal kugelrohr rig to pull the terps out. I run this rig until it pulls down to a few microns at around 150C. This indicates the terps are depleted and the compound is ready for the sublimator. The first bulb off the boiling flask catches the terps and the others are place holders. I have run cannabinoid out as well but not since I got the sublimator dialed in because it is better. Distillation just does not produce the same purity but for removing terps it is the only way for me.
After the horizontal rig then into the sublimator. I plan on two runs as a rule, cleaning out the boiling vessel half of the unit in between runs. Generally if I do everything carefully then two runs through the sublimator nails it down. At times a third run is done but that is sort of nit picky. Second pass yields the photo above and that stuff is very potent and does the trick for me. When it hits really high purity it lights up my endocanibinoid system like nothing else lolz.
Here is a close up of some first run in action in the sublimator. The white Teflon stir bar is stirring the liquid extract which is evaporating. When the gas hits the cold finger with ice water in it freezes onto the glass surface hard as a rock. This is the ultimate short path device. The gas travels about an inch. This is free molecular path flow conditions at 3/4 of one micron which means gas molecules can only flow in straight lines from the boiling puddle (on average). It cannot by definition “flow” around anything like a corner. So very little collects above the bottom of the cold finger due to this.
The cold finger seperates from the bottom boiling unit by releasing the vacuum. The ice is dumped and the compound thaws a bit and becomes an amorphous solid and peels easily. It there is still compound in the boiling flask then the cold finger is cleaned and replaced and the run continued. The cold finger can only hold so much before it stops freezing the incoming gas and then it just begins to condense the gas and starts to reflux (drips) so then it needs harvested.
Time for another dab and the sun is out. I love the green effect. This is the same Petri dish as above but in real light it really looks pristine. Very slightly pale yellow…Like me… lolz I am ready for sunshine! Oregon winters where I live are RAINY.
These are the gunk catchers from this run. This is what got seperated but waxes were trashed and not shown here. The left one is the first fractions that elute off a silica column and the black gunk with lots of green in it elutes well after the cannabinoids. So these photos show what I started with but seperated out. It looks like I can glean medicine from the first fraction so will save it for next months run. The black tar is gonna be tossed. Cool contrast.
Cool setup. Something I’ve noticed about the red coloring. It seems to be due to its interaction with water rather then oxygen directly. May have something to do with photons words about acids and bases requiring water to act as acids and bases… there must be an acid in there that gets stuck in the cannabinoids that’s activated by moisture or oxygen. Someone can probably form tests to confirm this theory.
Distillate doesn’t have to age… and doesn’t require MgO to balance the ph. The bump trap will remove all of the cause of the coloring issues of green and red
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.
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 guess… unless you made a heatable tray with multiple stir bars and a lid that was much the same shape… either way cool experiment.
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?
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 “deposition” 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 distillation… the MFP can be considered infinite within the bounds of that 1" space.
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 Corps…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.
@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!
Good insights on terminology. You clearly understand what is happening at those pressures or rather complete lack of pressure. Thanks for weighing in.