Co2 extraction w ethanol

Why introduce ethanol to refining when using co2 for purity in extraction?


Traditional C02 exteaction will pull fats and sugars, you got to use some sort of solvent to winterize I imagine.

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because without the ethanol, it is considerably more difficult to achieve said “purity in extraction”.

what you’re actually confused by is the misleading marketing many (most?) CO2 extraction companies use

eg: Pure CBG – Cannabigerol Extract Powder Isolate extraction education.


Thanks. I just find it counterintuitive that the benefits of co2 extraction is that co2 is pure. Then we get our crude and add in ethanol that we then require rotovap and distillation to remove . Almost negates the benefits of using co2. Am I right in my thinking, cycloparh? Thx

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What do you mean by “pure” exactly?

Pure CO2 and pure ethanol used on pure biomass equals pure product.


You have it backwards, assuming your end product goal is distillate.

Why introduce co2 when you’re going to use ethanol anyway?

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many would argue that just going straight to EtOH was the more rational route.

those that argue otherwise often seem to have invested in a CO2 machine.

I’m almost convinced that extracting with ethanol then post processing with CO2 is the correct strategy. except that I’m also fairly sure there is no right way…

we’ve got a long history with ethanol. current research suggests humans picked up their working alcohol dehydrogenase allele some 10 million years ago. which is 8 million years before Lucy walked the savanna. if you’ve got light colored skin, chances are your kinfolk wouldn’t have survived without alcohol…for a time there we were such slobs that we couldn’t drink the water. so I put ethanol in the “mostly safe” category…


Co2 + alcohol in a cxe system is (from what I hear) a pretty great solvent combo if your system is optimized for it.

Otherwise co2 only really shines for subcritical (terpene rich) oil, or post processing (Chromatography, etc.)


let me process all I have just read…thanks. Will come back with focused questions.


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Yea Im confused as well. Are you asking about winterization after processing with C02 or are you talking about CXE?

I suspect the former, but bringing CXE into the discussion is not unreasonable from an educational standpoint :rofl:

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We use both C02 and ethanol extraction equipment and then use ethanol for winterization and refinement. I would say the C02 offers more flexibility to run both subcritical and supercritical, we can pull terps off the beginning of the run and then ramp the pressure up during extraction, so we end up with a larger range of compounds, which is both good and bad. Overall it is beneficial for a very full spectrum extract with lots of terps, but it requires more refinement which we do use ethanol for, so I agree that the ‘pure C02/cleaner extract’ marketing is total BS. They are both clean when done right. The cryo-ethanol is very good at predominantly targeting cannabinoids (leaving out much of the wax) and you can run higher volumes with much faster run times, so that is where the bulk of the industry is headed for scale and efficiency. Just my two cents, I am still somewhat new to running all this…

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thank you for your reply. sure is alot of BS out there.

Have you any comment on these ultrasonic extraction systems?



If you first extract with ethanol to get to your crude, then what/how do you post process with CO2? AM very interested in what this process looks like- beginning with EtOh and ending with CO2.


I don’t have a solution, just a strong feeling that that particular rabbit hole might yield. Not currently exploring it. that would require parts not on hand.

although…there are parts of a home built CO2 extractor lying around the lab i’m currently calling home…:thinking:

the simplest thing to point to would be SFC eg Super crtical fluid chromatography ppt

but there are other advantages of using ethanol in your CO2 machine, see: Open source CXE retrofit for Co2 extractors

The problem is there are very few customers for a “pure” Co2 product. For self stable products elimination of waxs and lipids are necessary. While you can extract very clean fractions with Co2 it’s not commonly done because of the inefficiency of these selective extractions and the lack of a market for these products.

My agreement is if your going to add ethanol to a Co2 extract anyway, why not have the solvent do some extracting for you. Thus CXE allows you to extract at 10x the speed of Co2 alone with identical volumes of ethanol used for winterization.

The biggest plus to this CXE style system is that you can winterize inline using the JT cooling of the separator evacuation to cryogenically cool the tincture. In addition you get the antisolvent properties of the low pressure Co2 which increases the coagulation rate tremendously allowing for high quality winterization within minutes of the extraction.


thank you for the links. My Waters SC CO2 machine has the option of adding a CO-Solvent pump for EtOh. I will explore if I can rinse my biomass first with ethanol then conitnue with Co2.

All the best and appreciate learning from you.

How is post processing with CO2?

what equipment you use for CO2 and Ethanol extraction?