Greetings. First, thank you to everyone here, this place is an incredible resource and the only reason I’ve made it this far. We have a 2l SPD set up that we have been building over the last couple months that we can’t get to produce any volume of distillate.
Our process is as follows:
-Dry ice is added anhydrous food grade ethanol until temp stabilizes at approx -80c
-Cannabis (trim, small buds, so on) is added (in a 50micron bag) at a ratio of 1/10 cannabis to ethanol and lightly agitated for 5-10 minutes
-The cannabis bag is removed and the bag is pressed to to recoup as much extract as possible
-The Resulting extract (usually approx 10 liters) is filtered via buchner through 2.5 micron qualitative filter paper, collecting a sizable amount of epicuticular wax, this also forces remaining CO2 out of solution, stopping the mild bubbling
-The extract is then held overnight in a normal commercial freezer (-10c), then again filtered through qualitative filter media
-The extract is then rotovapped until all ethanol is removed and the resulting oil has the consistency of room temperature molasses
-The oil is then transferred to a 2l double neck flask and attached to a SPD head> three neck cow > three 250ml flasks. The cow has a vacuum take off running to a cold trap using black thick walled tubing, which then runs into a small vacuum manifold made out of a triclamp 1.5in tube and 1/4in adapters. the 2 stage rotary vane pump rated at 12.5CFM. The pump pulls 15 micron with the yellow jacket gauge screwed directly into it, 150 microns directly into the vacuum manifold, and 250 microns in the whole setup.
-The heating mantle is raised in increments of 5c at 250 micron. at approx 100c distillate appears to coalesce in small amounts on the vigreux fingers
- The temperature is raised very gradually until the mantle maxes out at 300c and the material becomes charred. The Kangaroo thermometer at the head reads room temp until well into the 200s, and even then only very light, clear fractions come over in very small amounts
-Our license requires that I use ethanol
-I’m aware that various aspects are made much easier with much more expensive equipment (jacketed cryo centrifuges, et cetera), however I can’t justify those expenses until the benchtop scale is proven to higher ups.
My theories (uneducated as they may be):
- The lack of long cryo exposure in something like a medical freezer is leaving more large molecular weight compounds in the extract, leading to more BTUs needed to cause vaporization and that thermal reality is above the point at which everything becomes a charred mess
- 250 micron is too high of a vacuum to be feasible in this process
-Processing with adsorbents could yield a lower molecular weight (Ihave carbon, mag-sil, bentonite and so on. But I am unsure as to which to use for this particular remediation.
- I have not sacrificed a lab assistant to Enthalpus, Lord of Vacuum Distillation, and as such he has cursed my endeavors. I am aware this is hubris on my part but I only have two assistants and can’t spare one right now.
Any ideas, oh learned men of the dark weed arts? I’m at a loss.