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Planning On Experimenting With Sfe Co2 Machine For A Cryogenic Co2 Expanded Ethanol Extraction

Discussion in 'Concentrates & Processing' started by progeny-prodigy, Mar 4, 2018.

  1. So subzero ethanol extractions r becoming increasingly popular recently and is probably where large scale processing is going right now. and I've been researching co2 expanded solvents (CXS) and realized how easily i could modify my machine for this process method. I have a jacket pressure vessels and large tanks of co2; all i think i would need is a large condenser, a cheap vac pump and the liters of high proof ethanol i would need (which is expensive here in cali but fortunately part of my design is a large vacuum still lol).

    Let me explain my idea without all the minutia first;
    Take ethanol that has been chilled(x) and add to my main vessel which has been prechilled to the same temperature (x) then dissolve co2 in cold ethanol (x) then add plant matter to the mixture (x) then filter into 2nd vessel (x) and distill most solvent under moderate vacuum (x) yielding a concentrated ethanol cannabinoid solution (x)
    ill end the abridged version there cause the final steps depend on what product ur going for and the exact parameters of the extraction. but almost always include purging of all the solvent at some point.

    Take ethanol that has been chilled(as much as u can) and add to my main vessel which has been prechilled to the same temperature (I could use solid or pressurized liquid co2 do this by pressurizing-depressurizing cycles or I could make a cryo-liquid coolant out of iso or acetone and dry ice and pump thru the jacket) fill only ~40% full to leave room for both expansion and plant matter. Then dissolve co2 in cold ethanol (I would add dry ice to ethanol then seal chamber and let the pressure build to start then i can also add co2 gas into the system from the bottom of the vessel. co2 gas becomes more soluble in ethanol as it gets colder so this has to be done till all the ethanol is at lowest temp) then depressurize the system and add plant matter to the mixture (after addition reseal vessel and wait 30-45 mins) then filter into 2nd vessel (piping co2 gas into to top pushes ethanol thru filter and into next vessel) and distill most solvent under moderate vacuum (apply at least enough vacuum so that ethanol can be distilled with hot water pumped thru the jacket and condense in a large copper, stainless steel or glass condeser with cold water and also an ice trap with dry ice cryofluid) yielding a concentrated ethanol cannabinoid solution (stronger vacuum can be applied to the vessel and left on low heat to fully purge or may be collected then purged in a vac oven) from what ive read u could also grow thca crystal from this if ur starting material is high quality.

    One of the biggest benefits of this process over co2sfe is crystallizing of thca from freshly harvested and frozen (wet) cannabis recently given the term "live" extractions or thru the well documented liquid-liquid extraction of the thca. ive also seen this referred to as the Polar-NonPolar (Pnp) or acid/base (A/B) extraction of thca. similar techniques r know for co2 but r much harder to adapt to my machine.
    Other potential benefits are yield and purity. and the yield is almost guaranteed to be better from what i understand its just if that yield is worth the decreased purity and process cost.
    The biggest absolute negative is reduction batch size. i am basically making the solvent in situ and adding the plant matter to that so the material and the solvent both hav to fit. instead of just packing the with as much as can fit lik co2sfe.
    This process might also be limited by how much can be dissolved it that volume of solvent which depends on the ratio of co2 to ethanol to water.
    Another big negative is purging. i use to make bho so i know how fucking annoying purging oil is and how much time and overhead it adds. with co2 i dont ever hav to purge and i can always say my oil is solvent free.
    and the setup cost is minimal and is for the same stuff i would need to buy to winterize my oil.
    Dunge and MirrorZen like this.
  2. Sounds like it should work? Most of it is over my head but from what you explained the theory is sound. That's awesome you were able to adapt to the situation and come up with a cost effective change. Go team!
  3. So your building a pressure vessel in order to precipitate thca? How is it solvent free when your adding ethanol back into it? I get co2 is solvent free due to using pressures to extract and not an actual solvent. Should work though, sounds like a solid sop for thca precipitation.
  4. Cryoguy


    hi guys I’m new to forem but was intreagued by your post.
    I own a company a new company that focuses on Cryo extractions. We’ve developed an ethanol co2 machine already. We have patent pending on it.
    Your idea is great. It will work. It has far more benefits than you may realize.
    I’m gonna protect my patents against resale but don’t believe In Keeping information secret so I’ll give you a few pointers.
    First co2 builds a lot of pressure. 980psi it will become liquid. That’s far greater than most vessels can handle so be careful to manage the pressure build up.
    Gaskets are really important. They have to rated for the tempstures which will reach -78c with slight variation in solvents ethanol acetone whatever. Tuff steel gaskets made by rubber fab are rated to -300
    Ball valves should also be cold service or Cryo otherwise they will lock up.
    Agatation. You have to agatate otherwise the goodies will be locked up in the spongy plant material after you drain.
    Agatation is hard In those temps but you can do it several ways. Co2 gas bubbled through the mix will work. Or a pump will work. This evenly distributed the dissolved resins in your solvent rather than leaving a concentration in and around the plant material.
    The tricky part is how to get the last of the ethanol out before it warms up.
    There will be about 20% left in the plant material after you’ve drained your system. In That 20% is also 20% of your yield. It’s worth it to get back.
    Not gonna day how we did it because we gonna sell this machine but I’ll tell you how to do something that works and is cheap. After you drain your system put you wet plant material in a salad spinner with a hand full of dryice and spin your ethanol out. The dry ice keeps it cold so it doesn’t turn green in the salad spinner.
    Lastly insulation. A jacketed vessel is good but it should be fully evacuated. Most pumps can do 10 to the -3. To function as a proper insulation barrier it needs to be at least 10to the -5. Otherwise your have issue maintaining temp and your dry ice will sub off very quickly.
    Be careful good luck
    Dunge and the rrock like this.
  5. awesome to find somebody actually willing to talk about it lol
    im planning on using ultrasonic transducers mostly for agitation.
    i hav many idea's fr each step its just hard to know without b2b comparison whgich i dont have the capital for atm
  6. Cryoguy


  7. Just out of curiosity approx how much oil would you get from a machine like this per LB on average?
  8. Cryoguy


    No machine creates oil meaning that yield is mostly dependent on starting material. 15 percent material will yield 15 percent minus whatever loss you have in the process.
    A good process and good machine should extract as much oil as possible. The one I’ve made does that. A 45 minute soak will pull about 98 percent of the goodies out and we can recover 95+ percent of the solvent. I haven’t done the math but that’s probably a 90 percent recovery of possible yield.
    Going much longer than that 45 minutes doesn’t really get that last two percent and it begins to pull green into solution.