Greetings hash wizards and warlocks,
In my never-ending quest to better understand the nuances of CO2 extraction, I wanted to direct some of my long-lasting questions to the CO2 extraction gurus within this forum to start a dialogue about methods and theories.
I have ~8 years of CO2 extraction experience with the legal industry space, but this experience has been mostly focused on the extraction of premium CO2 terpenes and highly potent oil in a production based setting, rather than any kind of R&D.
I am interested in doing some R&D to try to extract THCa from undecarbed plant material, but i dont know where to start. My question lies in the nature of manipulating solvent density to target specific compounds within the plant, namely THCa. I understand that changing solvent density is the single most important factor in determining what type of compounds are extracted, but my understanding of this concept is entirely practical and lacks the deeper theoretical understanding of this phenomena.
Can someone point me towards some academic articles that dive into the physics behind what is occurring when solvent density is manipulated? Why is it that terpenes and other volatile compounds are selectively extracted at a solvent density of ~0.2 - 0.35 g/m^3, while decarbed cannabinoids are extracted at higher SD, say ~ 0.6- 0.9 g/m^3. I get that it is a gradient and the compounds most soluble in the solvent will extract first, and less soluble compounds take more time, but I do not understand what is happening on a molecular level.
How is the polarity of the solvent changed as its solvent density is adjusted? Why are more polar compounds pulled at higher solvent densities, especially in supercritical settings? How is it that CO2, a non-polar molecule, can pull water during terpene-extraction parameters?
Finally, how can one approach finding the correct parameters to pull THCa from plant material while also not pulling waxes/lipids and other undesirables from the plant? I assume it will take some post-processing cleanup steps to try to isolate the THCa from the rest of the extract.
I am eager to hear your points of view on this topic, or if you can point me in the right direction to some resources that will help me better educate myself on this topic.
Thanks
. He say’s " Simply put, propane and CO2 are also, for these same reasons, harder and much harder , respectively, to induce into polarity". Nonetheless, supercritical CO2 will pull a significant water fraction during a terpene pull. I think this has to do with the “Debye force”, but not sure how to apply that in practice. Despite being a rigid non-polar molecule, it can definitely extract polar molecules, and therefore it is possible to tune the solvent to extact a relatively polar molecule like THCa…
