Affordable DIY CO2 Extraction???

[gunnaknow]

This is an excellent discussion. Regarding the amount of wax extracted, pressure is a key factor. The solubility of many compounds in CO2 vary with pressure. In the fragrance industry, there are two main types of CO2 extracts. Select Extracts and Total Extracts. Select Extracts (or simply Selects) are extracted at lower pressures and primarily contain the essential oil component. Total Extracts are extracted at higher pressures and contain additional plant waxes, fats, resins and pigments etc.

CO2 Selects:

Selects are oils which are extracted at lower pressures and contain only the volatile, CO2 soluble components. The heavier waxes, resins, and color compounds are left behind. The viscosity of a select oil is generally thick but pourable. These oils closely resemble steam distilled oils in composition, however, they may contain more volatile components that are not extracted during steam distillation.

CO2 Totals:

Totals are oils that are extracted at higher pressures and contain both the volatile and non-volatile CO2 soluble components of a plant. These oils contain the essential oil of the plant plus the heavier waxes, resins, color compounds, making them very similar to the plant itself. CO2 totals are generally thick and pasty but are soluble in essential oils and vegetable oils (although some may need gentle warming).

 

[JColtrane]

^ Nice I always thought pressure played a part in things

 

[JYNdustriez]

I recognized this in my sealed container hydrocarbon extractions vs column type, but the pressure range and difference is obviously much much less than my low end sc co2 extractions vs commercial systems.

I want to achieve higher pressures (~5000psi) at home at a similar affordability to my current set up. <NEW OBSESSION

 

[dybert]

I recognized this in my sealed container hydrocarbon extractions vs column type, but the pressure range and difference is obviously much much less than my low end sc co2 extractions vs commercial systems.

I want to achieve higher pressures (~5000psi) at home at a similar affordability to my current set up. <NEW OBSESSION

The selects vs totals and pressure talk is interesting.

***FROM OUR EXPERIENCE***

Lower pressure yields a much nicer looking, less wax concentrate.

We get our best results running around 1300PSI and COLD (45-50 deg) co2 (yes, this is sub vs super critical and we have a huge chiller to do this).

We get great yields, and great looking/testing product.

When we push the pressures and heat up we start pulling more chlorophyll and other nasties out. I really think striving for higher pressures isn't going to get you "nicer" or "better" oil. My 2 cents

 

[Gray Wolf]

The selects vs totals and pressure talk is interesting.

***FROM OUR EXPERIENCE***

Lower pressure yields a much nicer looking, less wax concentrate.

We get our best results running around 1300PSI and COLD (45-50 deg) co2 (yes, this is sub vs super critical and we have a huge chiller to do this).

We get great yields, and great looking/testing product.

When we push the pressures and heat up we start pulling more chlorophyll and other nasties out. I really think striving for higher pressures isn't going to get you "nicer" or "better" oil. My 2 cents

That sounds encouraging!

What is a great yield from the average prime bud using C02 at 1300 PSI?

About how much wax is removed during winterization when you extract at that pressure and temperature?

 

[JYNdustriez]

@dybert

So do you have a pump to achieve pressurization at low temps? Also, how much co2 are you moving through the material? At 1500psi my extracts are also very low wax and typically are a orange/red color.

I have purchased parts to conduct over 3000psi extractions. I am hoping they will allow me to produce consistent and higher yields and allow me to continue using low volumes of co2.

 

[G.O. Joe]

A few predicted and found solubilities (as mol/mol fraction of CO2) at different temperatures, from this abstract.

That article -
Solubility of non-psychoactive cannabinoids in supercritical carbon dioxide and comparison with psychoactive cannabinoids
Helene Perrotin-Brunel, Maaike C. Kroon, Maaike J.E. van Roosmalen, Jaap van Spronsen, Cor J. Peters, Geert-Jan Witkamp
The Journal of Supercritical Fluids Volume 55, Issue 2, December 2010, Pages 603–608

- is within this thesis and pdf that's very long, being a thesis -
Sustainable Production of Cannabinoids with Supercritical Carbon Dioxide Technologies
Helene Perrotin-Brunel
http://repository.tudelft.nl/view/ir/uuid%3Ac1b4471f-ea42-47cb-a230-5555d268fb4c/

- attached -
Inexpensive Fluid Delivery System for Supercritical Fluid Extraction
Janusz Pawliszyn
Journal of High Resolution Chromatography Volume 13, Issue 3, pages 199–202, March 1990

 

[dybert]

@dybert

So do you have a pump to achieve pressurization at low temps? Also, how much co2 are you moving through the material? At 1500psi my extracts are also very low wax and typically are a orange/red color.

I have purchased parts to conduct over 3000psi extractions. I am hoping they will allow me to produce consistent and higher yields and allow me to continue using low volumes of co2.

We have a pneumatic gas booster that drives the circulation of our system. This is run by a 15hp rotary air compressor.

 

[Useless]

Just wanted to mark this thread as I was just contracted to build a CO2 SCFE unit.

I see you guys are rocking in the 1300-1500 PSI range. Previous info I have researched suggested ~ 3000 PSI. Anyone using higher pressures in their set up? If so, how are the results compared to a lower pressure extraction? (Sorry if this has been answered, no time to read the entire thread right now..)

 

[gunnaknow]

Useless, just read page 5 and you will have your answer...

 

[gunnaknow]

I wonder, it might be possible to add a spray drier nozzle to the inlet at the top the collection chamber. It might allow you to produce a fine powdered extract, for ease of collection. Unless you plan to winterize, in which case you can just dissolve the concrete.

 

[dybert]

We can actually get a very dry golden powder, based on our extraction settings.

Sorry, meant to quote you gunnaknow.

 

[Gray Wolf]

We get a dry golden powder at about 85F with a Terpenator.

 

[JBizzness]

Dont dread the RED

Dont dread the RED

After re-reading one of GW pharma's patents they state a clear improvement with using sub-critical CO2 over supercritical.

Which makes me wonder if the reason why the few examples we've seen of supercritical extracts come out so reddish and have had such poor reviews.
It would seem Supercritical extraction pulls EVERYTHING out of the plant, and many of these compounds are undesirable. Innnnteresting.

They also state using 2% ethanol in a supercitical extraction improves yield but I didn't see anything about using co-solvents in liquid CO2 extractions. (this is from US7344736) Patents are frequently written to confuse competitors so who knows.

Back to liquid CO2 however, the mass flow they used was huge. 1250kg/hr for 60kg of plant material, over 10 hours. eek!

The pressure required for subcritical extraction is still way up there though, and to get a decent safety factor you'll still need to design for way over 1500psi.

I can't see liquid CO2 as being practical but I'm very interested to see some un-biased results as to whether it will work with a flow through system and if co-solvent will help. I wouldn't rule out using alloy steel since you presumably won't be using cryogenic temperatures and a chunk of seamless tube is going to be a lot cheaper in steel. Obviously ss is preferred but I wouldn't rule it out for experimental use...
What about a simpler test setup. Make a column with a valve at both ends and fill it with plant material. Get a small 2.5lb or 5lb. bottle of CO2 and connect it to one end of the column. The heater really isn't needed for sub-critical use.
If you kept the bottle valve and connecting column valve open you could flip it back and forth for soaking. Obviously liquid expansion needs to be considered but if the column is not closed off the bottle headspace takes care of that. I suppose you could dump the liquid co2 into another tank or just vent it onto a plate and see what comes out...

Awesome project dude, look forward to seeing results. A really awesome thing would be if you could do a hplc comparison test of say... ISO vs Butane vs liquid CO2 for the same plant material.

Peace RB

I have been honing my goo refinement skills since 2008, and up until recently ( after hitting a minor roadblock while constructing my SFE settup) I thought that I had reached the highest peak in BHE. The comment about the red coloration of the extract possibly due to over extraction of the plant. Assuming i understood the comment correctly or as intended, I must say that i dont feel that is the case. Just this last week I created something that made me feel as if i were trying to jump against the gravitational pull of Jupiter. It was labor intensive and timely. It is also "Dual or Tri-process" product depending on how you view it. I took three 5gal buckets of Blue Dream, packed em with ice and water, aggitated intensly with my DeWalt XRP drill and paint mixer attatchment and bagged it down to 24 microns. Beautiful and blonde it was..... Then i spread out roughly 3-1/2 oz of ( moldable consistancy) into a large pyrex cake pan and let air dry for about three days turning into a hazy sage color and coarse but easily crushable bed of limestone. Then of course i crushed to dust. That is the first process.
The second process was then packing the powderd bubble hash into the smallest of my extraction tubes and i do mean packed with a steel ramrod and my 240lbs of self. ( i did not weigh the bubble hash after dehydrating but my next run i shall keep detailed data across the board). The extraction tobe is a sch40 s.s threaded nipple "5x "1/2 and capped on each end. Then i blasted 1 8fl.oz. can of 5x refined butane through a s.s. screen roughly 160 microns. I will use a much finer filter in later runs.... I must also add that as a comparative, during this stage I also ran ( 1 tube/1 can ) sifted keef of the same strain Blue Dream side by side... Both bled out looking like very stiff " screwdrivers" to anybody whos had vodka and o.j. i was quite pleased at this point.
Then i evaporated the butane via the double boiler wich i love for its expedience.
Next, i pulled out my wild card which i love so dear and have influenced into other persons processes is my "heat gun" but you have to be careful and know by sight and smell how much is to much,close is to close, and is to long. This works wonders not just in purging out trapped butane and such but it also activates the THC. This by some could now be considered by some as the third process. I still only view it as second. Which brings me to the results of the two seperate containers and the point,theory,or question of this post. The batch made from sifted keef was a thing of beauty and as natural blonde as ive seen in y time...... But the other....... Was a cherry popper for sure at least to me it was. No blonde...... Thriugh and through it was " Sangri " or a fine glass of Pinot Noir. My theory is this. The pollens,tricombs etc which are yellow,cream,beige etc when concentrated or rendered,reduced gradually become deep gold, then burnt orange, copper, bronze and into red because there is actually less of the undesireables such as chlorophyls, and cytoplasms and such. Thus my tricomb packed bubble hash turned goo became red, and the high blonde is an opposite but similar result in that it is resulting from dilluting or partially bleeding out herbacous green plant material, Solid Green,light green, yellow green, and yellow. I know as an artist and from 30 yrs of mixing colors that the color scale process is sound but does the chemistry , process, and resulting product confirm my theory? I hope so because i have big fingers and i just typed all of this on my phone in portrait mode.... And if not im glad to participate and toss ideas andvthoughts around.... Either way ill be posting much more and soon. I am abssnitary welder for a stainless steel engineering company and i just finished mySFE setup for less than $100 and im quite impressed with it. As long asbit functions as expected. If not ill cut, configure, calculate, redesign,modify, weld and test again because thats what I do. Because im German ,Italian and as a result am relentlessly obsessive aggressive impulsive in a charge command and conquer then discuss it at great lengths until i figure out how to do it again and better type of person. Lol its true. And Mary Jane keeps me calm and tethered thank god.....happy holidays to you all

 

[nurgent]

I recently see a post with specific parts, est. Costs, machining specific etc. Could you point me in the right direction? Thanks so much

 

[Docmartin]

I have a question about the extraction process using CO2 and winterization to harvest.

If one is using winterization to harvest the product, why are all the different chambers necessary?

Consider a single vessel. Raw material goes in with some dry ice, heat it up to meet the necessary conditions for supercritical CO2, and allow the extraction to take place. Reduce temperature to meet vapor conditions and vent off the CO2 vapor. Now, collect all thats left in the vessel in ethanol, winterize, and filter.

Is this process technically sound?

A friend recently introduced me to the world of concentrates and due to my background in chemical engineering I have become engrossed in the separation process. Consequently, I would like to have a hand at making my own, but I am not up to speed on some of the technical information floating around.

Any advice and input will be greatly appreciated. Thanks!

 

[Gray Wolf]

Your oil bearing CO2 needs to be vented in liquid condition and then vaporized to leave the oil behind. If you had a single chamber separating the plant material and liquid C02 while it did that, it might work.

CO2 is a very small molecule and not a very efficient solvent, so it takes a lot of it. You can achieve that by pumping CO2 through the system at SCFE conditions, or do multiple extractions. http://jyndustriez.blogspot.com/ has a blog about doing a similar thing using liquid CO2, which you may find useful.

 

[Docmartin]

Ah, you are the man I was hoping to get talking. Thank you for your response.

Thanks for the link I have thoroughly gone through Jyn's videos and blogs.

I ask about the single vessel because it seems like part of the problems that people have (and from what I read Jyn had, also) is separating the product from the plant material and harvesting it.

Now in the lab I work at I have access to some 5 L 316 SS vessels with a fancy surface finish. I have some literature and can perform some calculations that should get me a decent estimate on how much CO2 I would need.

Assuming I have enough CO2 to carry out the extraction what would be the flaw in using the using a single vessel. Why is it necessary to separate plant material from liquid CO2 containing product, especially when you are going to put the product back into solution with ethanol and filter it?

Which brings me to another question. What is the advantage of using CO2 extraction if winterization follows? What is the advantage of using Butane extraction if winterization follows? Is winterization effective enough by itself?

Perhaps I don't understand winterization. It is one of the only topics I've had difficulty finding information on. I'm guessing the answers I desire are all contextual; it's all in how you measure it.

 

[Gray Wolf]

What is the pressure rating of the stainless vessels?

If you don't separate the plant material from the liquid/SC CO2 before evaporating off the CO2 as a gas, you will coat the plant material with the oil.

Washing it off with ethanol, will pick up non targeted polar elements.

 

[Docmartin]

What is the pressure rating of the stainless vessels?


Washing it off with ethanol, will pick up non targeted polar elements.

I thought that is remedied via winterization?