I am running a 6" Chinese-made wiped film distillation unit for CBD distillation. The first crude we ran through it ran like a dream. A bit of tinkering with the settings and with 183C evaporator, 70C internal condensor, and a 15ml/min feed rate we were able to get 75+% yields of ~85% CBD honey-colored distillate on the first pass. We pulled over 96% of the CBD in the crude to the distillate. The pressure while running was about 90 mTorr.
We then got some crude that was extracted with CO2. This material required 5-6 passes of the crude/waste fraction to get a decent yield of distillate. The lowest pressure we could get on the first runs were over 300 mTorr. The pressure decreases with subsequent runs. We chalked it up to an issue with the crude.
However, we got some new crude this week and things have gotten worse. The pressure in the unit is high while running and our distillate yield on the first pass was about 5%.
My best guess is that the crude isn’t completely decarbed and that the CO2 that is offgassing it raising the pressure, thus interfering with the distillation. @Munkdooligan had some of the previous crude tested after I sold it to him and it came back as having 6.5% CBDa. I only have a GC and I haven’t tried derivitization with it yet, so I can’t test for CBDa content. I sent some of the new crude off to the lab.
Today we ran a bit of the crude left over from the first batch, the distillate came out darker than before (like very light maple syrup), but otherwise it ran like it did originally, ruling out any hardware problems.
Could CBDa releasing CO2 be the problem with my system? Anybody have any other ideas?