Secrets to 90% cannabinoids (or better) on a short path?




Not sure if you wanna add any extra steps into your process, or extra solvents.

I’m finding a quick pass over silica with a quick dry load chromatography pull will get rid of 80-90% of your chlorophyll and wax using super chilled ethanol.

You’ll end up with an 80+% pure extract beforehand, this would make the refinement up to 90%+ way easier.

I can consult further if you want I don’t mind sharing more if you need.


I’ve been toying around with the idea of inline alumina/silica column into a co2 extractor, especially at crazy pressures like that you might be able to just freeze up the chlorophyll on the flowthrough. I’d be super curious to experiment with it on your setup, I’d do it for free :stuck_out_tongue: just to see if it works so I could use it on my own setup for later.


Interesting. Could you simply add the silica to the dry plant material and then run a normal extraction or are you thinking more of a hyphenated method?


No, to my knowledge all silica needs to be used in a filtration style method to be effective, i.e. column.


That was my hunch as well


It’s my understanding your biggest determining factor for success is going to be:

Getting adequate vacuum depth. If you’re not hitting proper vacuum depth, it will throw off the boiling points of anything you’re trying to distill.


Yes, I have noticed this effect as well. Ran 60% CO2 extract through wiped film and got 60% distillate back out. Only type of feedstock this ever occurs through, and since it’s wiped film that means it’s not a boiling flask isomerization issue, but rather something in the extraction stage.


I’m sure the parameters are already set beforehand, but that seems weird that you’re getting the same out as in. It should be going into a sort of reflux. Is it working properly?


This was like a year ago. It might have been more like 60% -> 70% post distillation, not exactly the same. But not remotely similar to the increases seen distilling other crude. Clearly something co-distilled.


You are definitely thinking along the right track. I hadn’t considered silica with ethanol since it’s a polar solvent, but hey if it works it works. I would estimate it would be a considerable amount of silica per kilo of crude, yeah? I’ll have to give a try. I can say that a polar/nonpolar liquid/liquid extraction did not improve the potency issue at all. I would be willing to collaborate and brainstorm on some of this stuff with you sometime. I’m operating in Riverside County.


Did you ever compare super and subcritical extractions? I know it’s possible to get good distillate out of the high pressure supercritical stuff since I toured a large scale lab doing just that. They were running wiped film, but I wasn’t allowed to tour the distillation setup, just the extractors. I assume it’s all working well for them since they are a non-stop operation. However, they did run a little less than 5000psi.


Silica has some dessicant properties and it can get compromised a bit by the water absorption. Silica would be good inline with Co2, but not as much with ethanol. Ethanol (in my experience) works better with alumina (aluminum oxide). You can get the same mesh sizes and everything.


Can’t say I did. The crude was prepared by a different company, and I’m not aware of their parameters.


I just hit 91.6% on this batch. I thought I had totally fucked up after I wasn’t paying attention and had crude shoot through the system and hit my cold trap.

Yea, that was fun, but I’m learning, so whatever.

I ended up taking that crude that shot through the system and putting it into a 500ml flask/mantle and just running it separately for practice. That subset hit 91.6thc/97total.

What is funny about that is it was just first pass cryo etho extracted crude.
No carbon scrub.
No c-bleach.
Old ass material from a failed farm.
An old SPD 1 short path from Summit with no frills.

I did put the e30 on that small setup which I think helped. Last time I ran that system with my Welsh and hit 87%. Putting on the e30 got me to 91%.

With the same setup on a 2L, I’m consistently hitting ~86%.

So maybe if I had a deeper vac for my 2L, I could hit 90+ on that too.


I have a hunch that smaller setups, such as 2L, are better at hitting higher purity. You don’t have to boil as hard to move fluids, and the runtime is faster. Not sure how true this is, but some of the best numbers I have hit on a shortpath have been from a 2L.


Running on my 2L, extracting biomass with -55c EToH I consistently see 88-95% cannabinoids, 85-93% THC.


Vacuum, evenly distributed heat, and a vigorous stir. Also filling your vessel only about 30%.

I cannot stress vaccum enough. If I was into experimental stuff in the industry and not just large production facilities I would rig up a nice 1 liter unit with a diffusion pump and get that vac down to about 1x10^-6 torr and be distilling at that.


Hi there - I run CO2 at similar temp. and pressure and have issues with potency when I distill dewaxed oil on Spinning Band distillation. Total cannabinoids range from 85-90% with d9-THC + THCa about 80-85%. Formulating with terpenes drops it below 80% THC. Would like to talk more.


You still have THCa after distillation ?


Is your 30% rule to limit residence time to reduce the risk of isomerization or something else?