Freezer burn had me down. I thought things might be hopeless and I’d be forced to make distillate with this flower.
Then I realized I had all of the components required to create a system capable of sublimating the ice: my rotovap, more vac, @Killa12345’s cold traps, dry ice, acetone.
Surprisingly there wasn’t much that came off! I didn’t fully vac these down to be extremely dry; I was mainly trying to expose the goods. I think a lot would break off if it was vacuumed to the point of brittleness. Spinning at 7 rpm was pretty gentle
I got to zero eventually, but the rotovap gauge only goes to zero so I also had a secondary vac gauge that got to 200 micron roughly. The minimum vac one must achieve to sublimate the water is 10 mbar when the water temp is at zero C. Lowering the bath temp further will require colder cold traps, so I was trying to sit right at freezing and maintain that temp.
The process I outlined above was a proof of concept that allowed me to purchase a used freeze dryer (lyostar) when I got the used unit it was non functioning because it did not have a correct pc and they do not sell one that is older software. The cost to refurbish was over 100k.
I decided to gut the beast and hook up my own chillers and vac. It’s working like a charm!
This thing has been pumping out kilos of freeze dried products no problem, so I scooped a second unit for 2k I’m about to demo and daisy chain the two for double throughput.
If you have a tight budget this is a viable way to get good throughput if you’ve got supporting ancillary equipment.
If you’ve got a huge budget call up Parker freeze drying and go hard!
This could be an option with some capacity. A door would be an easy enough fix. Note there does seem to be some damage in the picture on the right side.
Hard to want to pull the trigger on this stuff without more info.
It was a super fun project. I have the Huber running the lower coil down to -50 C if I have an opportunity to upgrade that to -80 I will. The shelves run from -20-40C so it doubles as a vac oven for secondary drying. The vacuum I change depending on the application, I keep my ice sublimation chart handy! For flower I use as minimal as possible but for nanoemulsions or other powders I drop it as low as my coil will allow without sublimating there.
.