CO2 Extraction Setpoint(s)

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Purpose: Researching Quality and Yield issues for CO2 Extraction.

Question: Does anyone have information on temperature and pressure profiles they wish to share, or tech documents outlining this information on cannabinoid/terpene extraction using CO2 super critical or sub critical extraction methods?
 
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Flashthunder, I appreciate you joining the conversation, but be careful making bold statements with no shown proof. In this patent, the applicant found that running CO2 extract at sub critical, over super critical levels obtained a cleaner initial extract and using sub critical levels, the user can selectively obtain cannabinoids and terpenes without solubilizing plant waxes before post processing occurred to purify the CO2 extract even further.

Using scientific method... on my 5L 2000psi unit, I had a starting point given to me by Eden Labs: 120F, 1600psi. So, I ran sub lots holding the temp at 120F, varying the psi from 1000psi to 1900psi in 100psi increments. I took each sample to a certified I502 test lab in WA, and had the cannabinoid profiles done and the precipitated wax total in each extract. The results explained that as the psi value went up more plant waxes were solubilized in the end. I wasn't finished in the study and selected 1000psi for my pressure and varied the temp from 70F to 140F in 10F increments. I then again had the test lab measure the terpene and cannabinoid profiles. It was found that more terpenes were saved at the lower temps. So my experiment shows me that if I want quality I will choose sub critical setpoints and if I want quantity, I will choose super critical. My next experiment will be to vary setpoints under sub critical parameters to see if I can selectively pull only terpenes.

Please explain why you use 120F and 2000psi. I didn't want to push my unit to this setpoint, but my results showed as I increased my PSI setpoint I pulled out more waxes. Thanks.

~Rhyno
 
I don't have peer reviewed papers to to support my claims. Only over then thousand of hours and hundreds of runs worth of anecdotal evidence.

120f and 1000 psi is a gas phase, so I wouldn't expect much there. While it's true that more waxes are extracted at higher temps/psi, its not because they are soluble. They are simply washed out because of the volatile environment. I think if you crunched the numbers you would find that the terpenes aren't simply being lost, they are being 'diluted' by the waxes. Sub-Critical runs do yield higher percentages of cannabinoids because the waxes are more viscous at lower temps and not extracted. Sub-critical will not pull all the di-terpenes though, so you are leaving psychoactives behind because of the high surface tension cohesion of liquid state co2.

I, as a business owner, always chose complete extraction over quality, because the market for high end concentrates just doesn't make it worth the loss in yield(yet). I doubt you'll have much luck selectively pulling terpenes with any standard system on the market(the polarities are too similar), although Greywolf recently did a write up on some work Eden is doing using break-through equipment, which is very promising. I would contact Fritz or Patrick at Eden, as they are the R&D team.

I'm glad to see you're doing actual research, the industry needs more people like you.

PS- Careful not too push your equipment beyond manufacturer specs, the psi ratings are only valid within certain temp ranges.
 
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Flashthunder, I appreciate your comments. I need to point out I had an incomplete thought in the above post... I didn't end my search at 120F, 1000psi. I actually now use 70F, 1000psi. only because I haven't hooked up a chiller to take the extraction vessel down past ambient. I haven't done any research down passed 1000psi yet. I need to do more research myself about the different polarity and how it effects extraction. Can you share your insight with everyone? Or maybe help point in the direction of good reseach - I have read some articles awhile back from Greywolf, I will refresh my memory... Question: If you run your extraction vessel at 120F / 2000psi, what do you set your collection vessel(s) too?

~Rhyno
 
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Flashthunder, I appreciate your comments. I need to point out I had an incomplete thought in the above post... I didn't end my search at 120F, 1000psi. I actually now use 70F, 1000psi. only because I haven't hooked up a chiller to take the extraction vessel down past ambient. I haven't done any research down passed 1000psi yet. I need to do more research myself about the different polarity and how it effects extraction. Can you share your insight with everyone? Or maybe help point in the direction of good reseach - I have read some articles awhile back from Greywolf, I will refresh my memory... Question: If you run your extraction vessel at 120F / 2000psi, what do you set your collection vessel(s) too?

~Rhyno
Depends on the system manufacturer, I'm a consultant now days so I work on many different systems. Liquid pump=700-900 gas booster=200-400.

1000psi and 70f is too close to a gas state for my tastes, density is too low.
 
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I'm not really interested in max solubility. I want the best quality and I've found that occurs slightly below 2000psi.

I often pull chlorophyll past 2500.
 
The solubility of THC in supercritical CO2 increases with both temperature and pressure up through 5000 psi at least and 140F. The solubility of CBD in supercritical CO2 plateaus at about 2500 psi and 130F. Chlorophyll becomes soluble in supercritical CO2 somewhere around 2900 psi at 104F.

Increasing pressure and temperature will increase your yield, but at the cost of a less specific extraction (waxes, oils, chlorophyll, etc.). You have to find your sweet spot with respect to what yield and quality you can accept.
 
H. Perrotin-Brunel, P. Cabeza Perez, M.J.E. van Roosmalen, J. van Spronsen, G.J Witkamp, C.J. Peters - Solubility of ∆9-tetrahydrocannabinol in supercritical carbon dioxide: experiments and modeling - J. Supercrit. Fluids 52 (2010) 6-10.

H. Perrotin-Brunel, M.J.E. van Roosmalen, M.C. Kroon, J. van Spronsen, C.J. Peters, G.J. Witkamp, Solubility of Non-Psychoactive Cannabinoids in Supercritical Carbon Dioxide and Comparison with Psychoactive Cannabinoids - J. Supercrit. Fluids 55 (2010) 603-608.

Omar, Jone; Olivares, Maitane; Alzaga, Mikel; Etxebarria, Nestor. Optimisation and characterisation of marihuana extracts obtained by supercritical fluid extraction and focused ultrasound extraction and retention time locking GC-MS. Journal of Separation Science, 36 (8), pp 1397-1404
 
CO2 extracted - rich terpene oil...the color and smell of these terps are insane.

Strain - Cannatonic
THC/CBD: 1.9% / 2.7%
Terpene Concentration 58.97%

Can get about a 0.5 to 2.0% yield of this type of terpene rich oil per run.
 
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I'm not really interested in max solubility. I want the best quality and I've found that occurs slightly below 2000psi.

I often pull chlorophyll past 2500.
Hey Flashthunder, i have been running some co2 extractions and i have been getting some oil carryover, any suggestions?
 
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SCH

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H. Perrotin-Brunel, P. Cabeza Perez, M.J.E. van Roosmalen, J. van Spronsen, G.J Witkamp, C.J. Peters - Solubility of ∆9-tetrahydrocannabinol in supercritical carbon dioxide: experiments and modeling - J. Supercrit. Fluids 52 (2010) 6-10.

H. Perrotin-Brunel, M.J.E. van Roosmalen, M.C. Kroon, J. van Spronsen, C.J. Peters, G.J. Witkamp, Solubility of Non-Psychoactive Cannabinoids in Supercritical Carbon Dioxide and Comparison with Psychoactive Cannabinoids - J. Supercrit. Fluids 55 (2010) 603-608.

Omar, Jone; Olivares, Maitane; Alzaga, Mikel; Etxebarria, Nestor. Optimisation and characterisation of marihuana extracts obtained by supercritical fluid extraction and focused ultrasound extraction and retention time locking GC-MS. Journal of Separation Science, 36 (8), pp 1397-1404
Waters sells a phase monitor for supercritical solubility measurements; I am just starting to learn how to use it. Pretty much you load a pure component (THC) for example, pressurize it with CO2 and heat it to see when it goes into solution. It's pretty cool, can't wait to play with it more for extraction/fractionation method development.
 
I would love to respond to this ad I am a technician for one of these research facilities doing supercritical extraction. I am just now doing the metrics at the transcritical phase([email protected] - [email protected]). Using my innate knowledge of BHO extractors, from the last 10 years building and operating them. I find that using the lower temperature/pressure runs yields a product of higher purity. Meaning the product extracted had less lipids/chlorophylls etc. On the con side of this equation, the CO2 acts less like a chemical/physical solvent (hcfc Butane, hexane, etc.) and more like an inert gas (physical [email protected]). Thus the time required to extract what you need is higher. Our run time for these metrics were 16 hours at 7.8241% yields with a 93.4412% purity and a 6% terpine content. Pictures coming.
For reference separator pressure/temp:
[email protected] [email protected]

However with these metrics I was never able to extract MidRun. the extracts would freeze up and I would have to heat up the separators to recover the oils.

I noticed that running higher pressures and higher temperatures/pressures extract everything faster and more as a liquid. Think of hot water dissolving and washing away oils. the hotter and the higher pressure dissolve or strip better than low. The fall back to this approach. Is that the time becomes the most important sensitive parameter. @15-20 minutes you may pull terps/oils-no waxes. And at 22m you start pulling chlorophylls and ruining you quasy vape-ready oil. The issue here is the sweet spot between the two. I will update you with ours. Thanks
 
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