co2 terp pulls ...

Wanting to start a discussion for terpene extraction using sub-critical co2 a solvent. Extractor / Separator S.V run time % of yields . Also has anyone made modifications to their machine to better improve this process ?


Subcritical CO2 terpene extractions pull out waxes and cannabinoids due to the solvent density. I recommend supercritical CO2 sub 300kg/m3 density. You only target the terpenes and hydrosol under those conditions. The hydrosol and terpenes can then be separated using a simple separation funnel.


What brand/type of machine are you running?

I’ve modded a Waters a bit for terps before, didn’t seem to make much difference. I just pull them all super-critical now, although, I’ve never gotten my density as low as @CriticalPoint mentioned.

I have managed to get what appeared to be wax-less terpenes and hydrosol, though.


Thanks , I’m running an Eden right now generally just do one large pull after our runs are up but I am now looking to start pulling terpenes to re-introduce to distillate as state regulations here are now calling for ingredients on anything that isn’t derived from cannabis.


Are you using the retrograde solubility functions of the Waters system to fraction out the terpenes or just using a specific extraction method to strip them out?

There’s a few different things I’ve experimented with, but, the extraction method I’ve worked out seems to be best standalone. Obviously, it always comes down to starting material, but, with the parameters I run it almost always looks good.

Purple strains and outdoor stuff never looks/smells as good. I wonder about how certain terpenes interact with the CO2 at certain temps and pressures. I’m pretty certain that terpenes that are especially light undergo specific degradation processes especially if over-exposed.

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Complete CO2 newbie here, only ran a few CO2 runs in my days and haven’t been taught much about it, but i’d like to understand the information you are explaining here, so I apologize if this is a silly question!

Any chance you could tell me how you are calculating your density?

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Its not a silly question. Understanding the solvent density is the key to getting what you want out of CO2.

I cant add links to my reply but if you send me your email I will send you some resources.


I don’t know. I have heard this before but have yet to see data to back it up. There are numerous studies on ScCO2 and terpene extraction from other botanicals and I haven’t seen one yet where they quantified degradation. If you look at the peer review they all seem to come to a similar conclusion that 300kg/m3 or under is a good solvent density for terpene extractions.

Its definitely possible that running too high of a temp would cause issues though. I run my terpene extraction at a set time of 45 mins per 3000g of feed and get great yields. Its all relative to the equipment and method though.


What are you guys calling terpenes?

Just the monoterpenes? What about monoterpene alcohols, sesquiterpenes and their alcohols, or even the triterpenes? Does anyone have data they’d like to show (don’t care about chemovar type) in terms of percent yields of material before and after.

Unfortunately, we sold our CO2 systems before I could research this so I have a tiny amount analytical data to present. The only experiment I have that was done is this sub-critical run. The tech didn’t record the parameters, of course, nor did they submit the material for a pre-run terpene analysis:

Terpene Profiling

64.11% Total Terpenes by Weight

Percent 	mg/g 	LOQ mg/g 	LOD mg/g 	Label Claim % 	Status

b-Myrcene 12.58 62.91 0.1 0.03 - Pass
Nerol 0.03 0.14 0.1 0.03 - Pass
Nerolidol 1.43 7.17 0.1 0.03 - Pass
Ocimene 0.61 3.04 0.1 0.03 - Pass
a-Bisbolol 3.30 16.49 0.1 0.03 - Pass
Farnasene ND1 0.00 0.1 0.03 - Pass
Valencene 0.88 4.39 0.1 0.03 - Pass
d3-Carene 0.04 0.19 0.1 0.03 - Pass
d-Limonene 3.07 15.37 0.1 0.03 - Pass
g-Terpinene 0.05 0.26 0.1 0.03 - Pass
a-Pinene 7.97 39.83 0.1 0.03 - Pass
Sabinene ND1 0.00 0.1 0.03 - Pass
b-Pinene 3.97 19.85 0.1 0.03 - Pass
Camphene 0.23 1.16 0.1 0.03 - Pass
Eucalyptol 0.31 1.54 0.1 0.03 - Pass
(-)-FenchoneND1 0.00 0.1 0.03 - Pass
Fenchol 0.92 4.61 0.1 0.03 - Pass
Camphor 0.03 0.14 0.1 0.03 - Pass
Borneol 0.09 0.45 0.1 0.03 - Pass
Pulegone ND1 0.00 0.1 0.03 - Pass
Cedrol 1.98 9.89 0.1 0.03 - Pass
b-Caryo 16.01 80.07 0.1 0.03 - Pass
Elemene ND1 0.00 0.1 0.03 - Pass
Phelladrne 0.09 0.43 0.1 0.03 - Pass
Isopulegol 0.07 0.35 0.1 0.03 - Pass
Linalool 1.42 7.11 0.1 0.03 - Pass
(+)-Fenchon0.07 0.34 0.1 0.03 - Pass
a-Caryophyl 6.45 32.25 0.1 0.03 - Pass
Guaiol 0.83 4.15 0.1 0.03 - Pass
Bergamotene ND1 0.00 0.1 0.03 - Pass
Terpineol 0.98 4.91 0.1 0.03 - Pass
Terpinolene 0.66 3.32 0.1 0.03 - Pass
a-Terpinene 0.04 0.18 0.1 0.03 - Pass

Yield was low and the machines were on their way out the door. But based on discussions with CANN ACS members yields can be improved to acceptable levels. Hydrocarbon yields and fidelity to starting material are much better than this.

But I believe claims made by CO2 terpene extractors so I’d like to have data so I can convince management to give it another go.

Thanks all.


Hi all I’m currently using a IES 20l system to pull Terpenes. Peramaters seem to do the job well but pull unwanted lipids and waxes. Been using the machine for 6months. Would really like to understand the system and science more. Anyone have links to info/books/studies on supercritical cow? Thanks gang.

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Here is the GC/MS data from the method I use. Its a mix of monos and sesquiterpenes. Due to the low density this method can be ran until complete extraction as there is no co-extraction of waxes or cannabinoids. The D9 that popped up in the analysis was likely due to carryover from the previous extraction. Unfortunately I do not have the feed material data.

Also here is the data from a 2nd extraction of the same material but at a higher density in the 500kg/m3 range. You can see much of the higher molecular weight terps were left behind partially and the waxes and cannabinoids are starting to be co-extracted.


how come the solvent density goes down with increasing temperature? Why not a subcritical run with 300kg/m3?

Also, any tips on processing the terpene pull afterwards??
Thank you

Great thread with a lot of data here, thanks @CriticalPoint !

How fresh is the material for a good terpene pull? Do people typically dehydrate the biomass with any heat prior to extraction, or it is all good as long as the moisture is under ~10%?

It seems 5% or less water content is ideal, you should be fine around 10%. I never use any type of heat or dehydration beforehand. I’ve posited getting a freeze dryer, not yet unfortunately.

Stuff that’s less than 6 months old I reliably get super nice pale yellow to orange terp fractions. (Seems to be stuff composed of 4 or fewer isoprene units.) Which all collects with water in my 3rd collection vessel. All of the stuff with more than 4 units goes into vessel 2.

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Does anyone know where I could find someone selling CO2 extracted terps? I’ve been looking everywhere but it’s been quite hard to find.

The several CO2 extractors I know of don’t sell their own, they use them. @TheFrenchie has a connection I think.


My connect is in “transition” from a lab to another, I will let you know as soon as they have some for sale. For now, I am using what I got left (not much). I am also on the hunt for that since I post that I was looking for that too. If there is someone in New Mexico or Oregon (I cant order from Canada bcoz of the state regulation) I can make something work I think, no lie, I DM every person with an Apex machine on IG lol


Just out of curiosity, if you can say, how much, roughly, do they charge for what quantity?

We used to have an APEX but no longer.

Last time I pay like 80-90$ per gram for an oz. Look like a fair price to me.

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