Post Processing "warm" EHO Solution

Hello F24K Friends,

Were in the process of bringing an Ethanol Extractor online, and I have some Questions and Concerns…
I was told the coldest our ethanol would be is -20 C on the first pass, and subsequent passes would be as “warm” as 0 C max. The unit requires a minimum of 30 Lbs of biomass and 30 gallons of solvent to run. Yes, there we have an industrial chiller. No, I don’t know why this Fiat sized machine can’t do better.

The idea is to be sure we pull all the desirable compounds along with the crap, to ensure a near 100% extraction of cannibinoids. In theory, this is great, but subjects my coworkers and I to some extensive winterization, filtration, and color remediation.

So, here are my questions/ concerns…

  1. Where to put the carbon scrubber? I’ve read on the forums here some people do it pre winterization and some do it post. Is there a clear advantage to one or the other? More specifically, does it have to do with the initial quality of crude solution? IE, is easier to implement this strategy when starting with a more pure solution? and will I slow or clog the flow by attempting to scrub such a low grade crude oil prior to winterization?

  2. What is the best way to stage the filtration to mitigate needing to change them as often? I should have access to 2 or 3 high pressure SS filtration vessels and can stage them either inline (which is the current set up, Large pore size to small) or in parallel depending on what should be most efficient. Here are my questions… For EHO post processing winterization what is the lowest micron you would suggest? I notice the 10 mic catches the majority of the fats and waxes. Is 100 too high? I believe the options are 100, 50, 25, 10, etc. With 3 vessels I was thinking of staging them in descending pore size, but hoping to catch more before the 10. The staging will obviously be predicated on what is deemed to be the correct/ appropriate sized final filter.

I really appreciate any advice, opinions, and or feedback!

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Uh, that’s not why you run cold ethanol to extract with at all, the idea is to pull less of the crap and as much of the cannabinoids as possible. If you run cold, you won’t pull as much fats/waxes/sugars that you’ll have to remove in order to distill cleanly. Also I don’t think 100% extraction efficiency is realistically possible (or at least, does not happen cost effectively and scale well). Something to consider for the long term.

I don’t think 0C is near cold enough to produce quality crude but I’m curious why on subsequent passes you get so much warmup. I would think you could do better than if you’re reusing solvent by puming it into a holding tank that’s jacketed and kept cold in between passes, though without more details it’s hard for me to know exactly what your setup looks lie.


Hello! and thanks for the reply.

I totally know what you mean. But this was purchased prior to me gaining employment with this company, and while it isn’t necessarily my job to get it on line I have to deal with the green soup it will inevitably spew…

Let me ask the “mechanic” some more questions so i can better address your other points.

You can definitely create fantastic end product with a warm EtOH extraction.

It might look something like this: warm extract, decarb, winterize (0C then 40C), recover EtOH, LLE with Heptane and Water, carbon scrub(if necessary), recovery heptane, feed to distillation.

Certainly it’s possible but it’s a lot of work, certainly more work than if you don’t don’t pick up those nasties in the first place, and IMO winterization doesn’t scale easily, and warm ethanol extraction is bound to require more attention paid to reproofing your solvent.

If you’ve got the ability to get down to -20C it would certainly reduce the amount of cleanup you’re going to have to do after the fact, though I certainly sympathize with @TheMadDabber 's situation where they’re having to run & maintain equipment that they had no say in the sourcing & purchase of, because I’ve certainly been in that situation myself


Another issue is, you have to determine the solubility of THC in ethanol at different temperatures. If you’re not pulling 20%+ of cannabinoids because you’re too cold, you could be losing too much potential revenue.