Hey all, I’m in the market for an extraction system and am trying to decide on whether I should go with a CO2 or Ethanol extraction system. I wanted to run by a couple questions/assumptions before making a move.
Assumptions (please challenge me):
-Bio availability will ultimately drive long-term use of CBD products, and therefore vaping, sublingual tinctures, and nanoemulsified food/beverage products will make up the lions share of the end user market.
-Organic, full/broad spectrum extracts will dominate the tincture market. CBD isolate will dominate the infused F&B market, and vape/concentrate market.
Questions:
What are the differences between the crude CBD oil from cold-extracted ethanol and CO2 systems? Any differences relating to decarboxylation? Is there a market for CBD-A?
Is there a role for warm ethanol extraction anymore?
CO2 is good for terpene extraction. Is this relevant for CBD concentrates? Or is it the case that concentrates are made with CBD isolate or distillate and terpenes and propylene glycol are added separately?
Co2 is generally ran supercritical at temperatures that pick up a lot of fats. The winterization and filtration process adds a lot of time to your process. If you extract with ethanol at cold enough temperatures, you’ll have little to no fats. Running ethanol warm creates a lot of post processing issues and adds a lot of time to your overall process as well.
2 Likes
The words ‘Bulk Extraction’ & ‘CO2’ don’t belong in the same sentence… whatsoever.
6 Likes
Are the fats you talking about where the terpenes are located? / is this why CO2 is good for terpene extraction?
Hey there. I run a couple CO2 extraction machines in the recreational Washington industry. I can tell you now that unless you are willing to spend upwards of a million dollars on extraction equipment alone, CO2 is not going to be the best solution for large scale hemp extraction. Unless you are planning on creating craft, small batch products I would steer towards ethanol extraction. CO2 does have a better capability of extracting specific compounds, if you are attempting to target certain cannabinoids or terpene profiles and don’t mind the long processing times and potential post processing involved.
Also just from your last comment there, I think you should do a little more research on the differences between the extraction methods. The terpenes are not located in the fats, CO2 when in a supercritical fluid state is known as a “tunable solvent”, which means that the solubility of compounds in it varies based on the temperature and pressure (two main properties controlling the molecular density of CO2 in your machine). You can modulate your run parameters to selectively extract just terpenes, or cannabinoids, or both. Typically though when doing a full extraction of cannabinoids with CO2, you will also pull many fats and waxes which are quite soluble in supercritical CO2 at the conditions that are best for pulling cannabinoids quickly.
2 Likes
The main question you should be asking is “What am I trying to extract from my biomass?”
If the answer is cannabinoids, ethanol is the way to go. If the answer is terpenes (and only terpenes), you may want to look into large scale steam distillation as that will be significantly cheaper than CO2. If the answer is small batch, craft products that are full spectrum with high terpene content, then choose CO2. But do so knowing that your extraction run times will be exponentially longer, and yields lower than ethanol.
1 Like
Thank you sauceboss, that’s very helpful. For the craft products you’re talking about - is this mainly for concentrates like dabs / shatter? It seems most vape liquid just uses CBD isolate and a mixture of PG.
For dab products such as wax yes, but CO2 extraction is notoriously difficult to produce stable shatter with due to the temperatures that supercritical extractions operate at (shatter requires the majority of THC content be in THCA form, and supercritical CO2 extraction partially decarboxylates the material).
CO2 is quite good for producing concentrates for vaping. Do your supercritical extraction to yield a fatty, terpy crude material, winterize it to remove fats and waxes, then decarboxylate to yield a clear amber oil that will work in any vape pen or cartridge. However, with current laws and limits doing this with hemp will give you something that tests hot for THC. Most hemp CBD based vape liquid just mixes isolate, PG/VG and botanically derived terpenes. This ensures that your THC levels will be below limits, as you are starting with a relatively pure CBD product with little to no THC and further diluting it.
I think the future of “full spectrum” tinctures and the like is that every cannabinoid in the mix will be extracted separately, in an isolate format, then recombined at specific ratios to achieve the desired end result. With all the hemp CBG coming down this year, and hemp CBC that will be coming soon, I think that is in the very near future. And isolate production is most efficiently accomplished through ethanol extraction, regardless of if you are targeting THC, CBD, CBG or CBC.
Cold Extracted Ethanol crude is the easiest handle with minimal post processing required before going into distillation. The reason ethanol extracted crude isn’t viable for terpene collection is because of the higher temperature required to evaporate off ethanol compared to CO2 or Butane systems. When you get your temperatures high enough to evaporate EtOH, you’ve already boiled off all of your terpenes.
As others have mentioned, CO2 is unique in that you can “tune” the solvent using pressure steps to crash out different component fractions. One of the high end CO2 systems I looked at had collection at 4 different pressure steps for THC, CBD, Terpenes, and Water. Bear in mind, these separations are not perfect and each fraction collected still needed significant post-processing to become a usable product. The use of extreme high pressures also partially decarbs the material.
The 3rd option, which hasn’t been mentioned yet, is hydrocarbon extraction. In my opinion, this is kind of the “best of both worlds” in being able to extract both cannabinoids and retain terpenes at the expense of being at risk of blowing yourself up or setting yourself on fire (both of which can still happen with EtOH extractions) if you don’t take precautions. There is also the legal issues where I’m pretty sure Butane extraction is straight up outlawed depending on where you’re at. Even if it isn’t, you better have your ducks in a row when you go to talk to the local fire martial, and even then he might not be impressed with your safety precautions and deny you. Finally, hydrocarbons are much better at extracting fats than EtOH, so you still have to go through a dewaxing or winterizing step before going to distillation.
Thanks so much for your feedback. I definitely hadn’t considered the future of isolating more cannabinoids. Mind if I ask why ethanol is best to produce cannabinoid isolates? In comparison to CO2, such as mcpikeig mentioned below, which can be tuned to extract different plant components? Is it also the temperature of ethanol that allows it to have more affinity for specific cannabinoids?
Thanks mcpike, and yes I am probably going to avoid butane for the reasons you mentioned. Why is cold extracted ethanol the easiest format to purify? Are you talking about using chromatography to purify the crude CBD?
Cryo EtOH extractions require the least amount of post processing (winterization, filtering) before going to distillation. I personally don’t have experience with EtOH, but from what I’ve heard you can pretty much go straight to distillation after you’ve evaporated your EtOH.
with CO2 or Hydrocarbons, the primary clean up step is “cold ethanol”.
so, logic goes, start with cold ethanol, and skip the dangerous or expensive step…
1 Like
Still need to winterize, purge, and decarb before spd.
True. C02 does have a shit ton of waxes and fats. And winterizing process of c02 is definitely time consuming. Being that you have to refreeze the crude for every micron filter necessary to get clear clean product. As for cold Ethanol extraction it cuts down the processing time by leaving behind the fats and waxes. I use a lenticular filter with carbon and with one pass the crude is Clean clean and ready for evaporation and then to distillation. Much more faster than c02. But I notice lower yields using Ethanol.