Sciencemadness Discussion Board - Cannabinoid concentration

As I said the cannabis world is rather tight lipped

This might be true for the cannabis world, but it is not for the scientific world. Cannabis and its compounds are very well studied because of the obvious. Try to have a look around here:
https://www.ncbi.nlm.nih.gov/
Usually it is a good start; not all new articles are in their databases, but after a year or so most articles end up in there. Material and methods is often a rich source for protocols.

I found scientific articles completely un-understandable at first, but just hang on and keep on reading, at some point you will get the hang of it.

Crowfjord - 10-3-2018 at 15:01

I believe limonene is steam distillable whereas THC is not, so steam distilling would probably separate the mixture. Regular distillation would probably work too, since the actual boiling point of THC is much higher than 157 °C.

After cannabis became legal in my state at the request of a friend I made a distilled extract for him from his home-grown plant material. I first extracted the coarsely ground buds by gently swirling in -12°C 99% isopropanol (3x100 mL or so for about 14g IIRC). The solution was filtered, distilled until most of the solvent was collected, then the last solvent removed under aspirator vacuum and heating with a hot water bath until all traces of solvent were removed. The light brown extract thus acquired was then vacuum distilled through a short path at about 1 mm Hg. A clear colorless oil came over around 180-200°C. It was very viscous but not quite solid, and yellowed and darkened over time. I don't know about THC concentration, but it was judged to be very very potent.

[Edited on 11-3-2018 by Crowfjord]

violet sin - 10-3-2018 at 18:44

Pacific northwest eh? I'm in California and adult use is legal. I however don't know the legality of making your own concentrate. As far as I can tell, medical patients are allowed to use safe extraction methods and adults in general can use/have up to 8g, but nothing about making it as a private citizen. You surely couldn't transfer it for any kind of trade or sale b/c of the huge fines for unlicensed manufacture, transportation, distribution and sale of a controlled substance(at least not here). They would bag and tag your ass quickly given the chance, with prejudice since there are legal routes.

I'd say it is pretty weird change of pace. A friend just remarked only two days ago "it's so strange to be able to drive to town and buy pot as if your getting a gallon of milk... Crazy". Still not allowed to smoke in public or drive of course, but if it's in your pocket no problem.

Morgan - 10-3-2018 at 19:50

Off topic but just wondering if this is dramatically effective or not?
https://therooster.com/blog/keep-calm-and-listen-neil-youngs...

Tsjerk - 10-3-2018 at 22:41

https://sci-hub.tw

Copy the DOI number from any article too here in order to avoid paying for articles. Maybe not completely legal, but hé, we are not making any money out of it anyway right?

[Edited on 11-3-2018 by Tsjerk]

ave369 - 11-3-2018 at 02:00

What are you trying to make: cannabinoids as chemicals of reasonable purity for experiments, or cannabis concentrate for personal use?

NEMO-Chemistry - 11-3-2018 at 13:52

Critical extraction with CO2 is the most effective and safest route, plums use Butane but CO2 gives a very clean extraction and is generally the preferred method. There is a forum named after a date in March (cant remember it all now!!) but some date connected with cannabis, the forum is an excellent source of information.

Where i live its totally illegal so obviously the above info came to me via someone else dream who passed it on to someone else and i then overheard it etc.......

[Edited on 11-3-2018 by NEMO-Chemistry]

brubei - 11-3-2018 at 14:35

Here again, critical CO2 is the best known method. Extraction result in a clear oily wax.

Tsjerk - 12-3-2018 at 02:32

Are there any examples of amateurs (ones that don't buy a ready to use system) getting a super-critical CO2 extraction done?

Sidmadra - 12-3-2018 at 13:30

OP I think you are getting some things mixed up.

The procedure you describe with the limonene sounds like it is being used as an azeotropic distillation agent. In simple terms, it is being used to entrain the terpenes and carry them over out of the mixture. This allows higher boiling terpenes to be removed without raising the heat too much. In a rotovap, this would likely be very efficient. Since rotovaps have such a high surface area of evaporation, and tend to have lower separation coefficients, this method could quickly leave behind relatively pure cannabinoids in the evaporation flask. You'd probably still want to recrystallize them in the end though. To reiterate, in this procedure, the cannabinoids stay in the evaporation flask, you are not distilling those over.

A rotovap is doubly useful in this regard because they often have the ability to continually add solvent as the evaporation progresses, without having to take the apparatus apart or remove much of the vacuum.

Some notes, you would definitely need to do this under a vacuum, and I definitely I wouldn't do this procedure with a heating mantle, as it relies upon controlling the heat source well, so it'd probably be more wise to use an oil bath.

This of course isn't the only way to obtain pure cannabinoids. They could probably be isolated very easily by recrystallizing from the right solvent combination. Since terpenes tend to be liquid and having lower boiling points than the desired cannabinoids, they should be able to be easily separated by crystallization, owing to their higher solubility.

I miss living in a medical state and being able to try things like this. Personally, I don't know why people want to remove the terpenes. The terprenes are primarily what give the strain its unique profile and effects.

[Edited on 12-3-2018 by Sidmadra]

Morgan - 12-3-2018 at 13:40

OP I think you are getting some things mixed up.

The procedure you describe with the limonene sounds like it is being used as an azeotropic distillation agent. In simple terms, it is being used to entrain the terpenes and carry them over out of the mixture. This allows higher boiling terpenes to be removed without raising the heat too much. In a rotovap, this would likely be very efficient. Since rotovaps have such a high surface area of evaporation, and tend to have lower separation coefficients, this method could quickly leave behind relatively pure cannabinoids in the evaporation flask. You'd probably still want to recrystallize them in the end though. To reiterate, in this procedure, the cannabinoids stay in the evaporation flask, you are not distilling those over.

A rotovap is doubly useful in this regard because they often have the ability to continually add solvent as the evaporation progresses, without having to take the apparatus apart or remove much of the vacuum.

Some notes, you would definitely need to do this under a vacuum, and I definitely I wouldn't do this procedure with a heating mantle, as it relies upon controlling the heat source well, so it'd probably be more wise to use an oil bath.

This of course isn't the only way to obtain pure cannabinoids. They could probably be isolated very easily by recrystallizing from the right solvent combination. Since terpenes tend to be liquid and having lower boiling points than the desired cannabinoids, they should be able to be easily separated by crystallization, owing to their higher solubility.

I miss living in a medical state and being able to try things like this. Personally, I don't know why people want to remove the terpenes. The terprenes are primarily what give the strain its unique profile and effects.

[Edited on 12-3-2018 by Sidmadra]

Might the terpenes in beer/hops have any marginal effects if indeed the terpines modulate paranoia/anxiety?

Another curious tidbit (if true). Not really a scientific source and all.
"Oh the other hand, some terpenes life Myrcene from mangoes seem to turbocharge THC, which could be a good or bad thing. Possible one's effective dose might be reduced."
https://mmjdoctoronline.com/health-news/black-peppercan-cure...

[Edited on 12-3-2018 by Morgan]

NEMO-Chemistry - 12-3-2018 at 14:02

CO2 super critical is really easy at home, a plastic tube used to clean aquarium gravel, a CO2 cylidar with the tube going to the bottom so it makes dry ice, cap off both ends the plastic tube, one end make loads of 1mm holes and the other make one hole with a barbed pipe fitting.

Fill plastic tube with the erb and fill tube with liquid CO2, let it all find its way out the little holes (put a bowl under it). Simples and cheap, its done alot with Lighter gas in tins but dont do that!! really bad fire hazard in my dream.

OldNubbins - 12-3-2018 at 19:39

What kind of plastic tube should I use to hold roughly 73 atm. of pressure? "Little holes" and "super critical" don't sound like they go hand-in-hand

Mister E - 13-3-2018 at 01:04

As I said the cannabis world is rather tight lipped

Sadly thanks to very repressive regimes of yore even the scientific data is often contradictory. But I'll dig through the link you sent and see if there is anything decent on the subject however the discrepancies around the BP I mentioned in my OP do not come from the grower world but from reputable scientific sources.

Mister E - 13-3-2018 at 01:06

Quote: Originally posted by Crowfjord

I believe limonene is steam distillable whereas THC is not, so steam distilling would probably separate the mixture. Regular distillation would probably work too, since the actual boiling point of THC is much higher than 157 °C.

After cannabis became legal in my state at the request of a friend I made a distilled extract for him from his home-grown plant material. I first extracted the coarsely ground buds by gently swirling in -12°C 99% isopropanol (3x100 mL or so for about 14g IIRC). The solution was filtered, distilled until most of the solvent was collected, then the last solvent removed under aspirator vacuum and heating with a hot water bath until all traces of solvent were removed. The light brown extract thus acquired was then vacuum distilled through a short path at about 1 mm Hg. A clear colorless oil came over around 180-200°C. It was very viscous but not quite solid, and yellowed and darkened over time. I don't know about THC concentration, but it was judged to be very very potent.

[Edited on 11-3-2018 by Crowfjord]

Nice, short path purification of a RSO. Sounds like you were making a version of the product being marketed in Colorado as "the clear"

Mister E - 13-3-2018 at 01:18

Quote: Originally posted by violet sin

Pacific northwest eh? I'm in California and adult use is legal. I however don't know the legality of making your own concentrate. As far as I can tell, medical patients are allowed to use safe extraction methods and adults in general can use/have up to 8g, but nothing about making it as a private citizen. You surely couldn't transfer it for any kind of trade or sale b/c of the huge fines for unlicensed manufacture, transportation, distribution and sale of a controlled substance(at least not here). They would bag and tag your ass quickly given the chance, with prejudice since there are legal routes.

I'd say it is pretty weird change of pace. A friend just remarked only two days ago "it's so strange to be able to drive to town and buy pot as if your getting a gallon of milk... Crazy". Still not allowed to smoke in public or drive of course, but if it's in your pocket no problem.

Every state has there own set of rules. I'm able to grow smoke and do whatever except sell with my own stuff here. The state limits commercial production to "butane, CO2, and any other solvent the MCB (marijuana control board) approves in the future".

CO2 does not make a decent shatter. You can get honey oil and pre-loaded cartridges but nothing resembling a decent dab unless it has gone through further processing. Also Supercritical systems start in the mid 5 digit range.

Butane has the obvious issues with hydrocarbons and some peoples refusals to have anything to do with them. his goes so far as to there being lighters that have a piece of hemp wick attached so you use the lighter to light the wick then the wick to light your weed.

I want to follow in he footsteps of the few how have made LHO shatter. I know there are limonene isolates that reduce it to 99% pure THCa and while I would like to be able to do that my main goal is to produce a hydrocarbon free shatter that contains a decent terp profile. If this ends up by using steam distillation to create full profile terp solutions and reintroducing it after my LHO shatter has been vac purged so be it.

After I have my legal home pilot plant running I will take it before the MCB and get the approved to move forward with a legal commercial operation.

Mister E - 13-3-2018 at 01:24

Quote: Originally posted by ave369

What are you trying to make: cannabinoids as chemicals of reasonable purity for experiments, or cannabis concentrate for personal use?

Yes. I would love to be able to create pure refined cannabinoids of a large variety to experiment with as so little has researched so far beyond THC and CBD. Also I want to create cannabis concentrate that is free of petrochemicals and can be added to the list of approved commercial methods.

Mister E - 13-3-2018 at 01:35

So your suggesting the Limonene forms an azotropic bond with the terpenes and helps in removing them to purify the final product?

I know the initial extraction from raw plant material is being done under vacuum with limonene.

Furthermore there is a recrystallizing method referred to as "winterization" using ethanol. I also know this is being done to the extract after the limonene is removed.

I agree with the idea of keeping terpenes in he mix as much as possible and plan on experimenting with steam distillation of terpenes separately so that I can reintroduce a full profile after the concentrate is purged.

I know a rotovap would be a huge help. It's at the top of the list of things I want to add. I have a mantle and I know it was done with a mantle before however it seems to be much harder. that's okay, I'll put in the hard work with what I have to form my proof of concept.

Yes everything will be done under vacuum. Both my fractional distillation and a purge in a vac chamber after.

And yes my plan was to distill off the limonene from the THC not the other way around despite the claim from some sources that THC has a lower BP than Limonene.

[Edited on 13-3-2018 by Mister E]

Mister E - 13-3-2018 at 01:49

Quote: Originally posted by NEMO-Chemistry

CO2 super critical is really easy at home, a plastic tube used to clean aquarium gravel, a CO2 cylidar with the tube going to the bottom so it makes dry ice, cap off both ends the plastic tube, one end make loads of 1mm holes and the other make one hole with a barbed pipe fitting.

Fill plastic tube with the erb and fill tube with liquid CO2, let it all find its way out the little holes (put a bowl under it). Simples and cheap, its done alot with Lighter gas in tins but dont do that!! really bad fire hazard in my dream.

What you speak of is known as open blasting. While it does work with butane (your "lighter gas) it does not work with CO2 as there is no way to put the CO2 under the pressure needed for it to reach a supercritical state and effectively strip cannabinoids.

ave369 - 13-3-2018 at 01:49

I want to create cannabis concentrate that is free of petrochemicals and can be added to the list of approved commercial methods.

With this I can help. Use extraction with liquified gases. The industrial method is using CO2, but this requires high pressure. For home lab, butane is the most convenient gas. It remains liquid at relatively high temperatures at standard pressure yet completely boils off, not leaving any hydrocarbons behind.

Treat cannabis with liquid butane at lowered temperatures or elevated pressure. Once the extraction is complete, lower pressure or raise the temp, the butane will completely evaporate, leaving you with a viscous concentrate that could be used for both personal use and further purification.

Mister E - 13-3-2018 at 01:52

My last package showed up today but sadly one piece is broken =( so it's another week or so now till I'm ready to begin but I will check back in and post updates of my work soon.

Mister E - 13-3-2018 at 01:57

Quote: Originally posted by ave369

I want to create cannabis concentrate that is free of petrochemicals and can be added to the list of approved commercial methods.

I want to avoid butane. There are already a handful of labs here manufacturing with butane. I've seen the test result, every one of them has residual butane let over. The states requirement of a concentrate "passing" a residual solvent test is not the same as it having no hydrocarbons left behind.

My goal is to re-create the LHO (Limonene Hash Oil) product that is manufactured in the British Columbia area. Outside of that one lab I do not know of any commercial LHO manufactures. Thus the hard time finding reliable information unlike BHO where there is a ton of information and relatively inexpensive closed loop machines that are shipped out as turn key operations.

Bert - 13-3-2018 at 06:16

Quote:

For home lab, butane is the most convenient gas. It remains liquid at relatively high temperatures at standard pressure yet completely boils off, not leaving any hydrocarbons behind.

Technical butane is NOT a food and drug grade material. The cheap stuff happy home hash oil extractors frequently use is contaminated with various oily hydrocarbon crap, which does not boil off into the atmosphere so readily. Even the slightly better stuff some cigarette lighter companies tout as not wrecking the electrical ignition systems of fancy lighters is nothing you want contaminants of in your lungs.

I use butane for stage flame effects, from what I have learned maintaining the ignition systems and burners, I wouldn't be using a non FDA tested grey market product that began with a cheap butane for extraction. Cheap, easy, good: choose any two, as usual.

I have no idea what grades are available, or what contaminants will be found in cheap d-limonene. Hope being an early adopter is not something you will regret later in life. Lungs: Only two issued per customer.

NEMO-Chemistry - 13-3-2018 at 06:21

I have seen it done using a soda stream CO2 bottle, it didnt work as well as a large CO2 cylinder but it worked fine.
The only time i seen CO2 not work was with a CO2 cylinder used for Beer in pubs, these dont have the tube inside the cylinder going to the bottom, they take the gas from the head space.

This isnt my thing, but I can assure you i seen an amber potent liquid drip like nectar using CO2. And i am told (yes seriously i havnt tried the stuff) that it smokes better than Butane extracted.

Dont shoot the messenger, i am only telling you what is apparently a very common practice in some areas of the town nearest to me. Known locally as weed world

.

The other one i have heard about but not seen was the cream fluffer gas stuff, I think they were on about Laughing gas but hard to tell with that particular group of....acquaintances

[Edited on 13-3-2018 by NEMO-Chemistry]

Tsjerk - 13-3-2018 at 11:46

Does anyone know at what pressure CO2 gets critical at low temperatures? 73 atmosphere is apperently for ambient temperatures

Vomaturge - 13-3-2018 at 12:38

I don't think it can get "critical" unless it is at least 31 C and 73 atmospheres:
https://en.wikipedia.org/wiki/Supercritical_carbon_dioxide
As far as what pressure will liquify it at cooler temperatures, this calculator might help:
http://www.peacesoftware.de/einigewerte/co2_e.html
Bear in mind that below about -56 C, pressure will only solidify CO2, but not liquify it.

Edit: I might add that if there is liquid CO2 present (i.e. a denser water-like phase that settles to the bottom of the pressure chamber), than it's probably NOT supercritical. This might be more of a technicality, though. Just because CO2 cannot work for a supercritical extraction below 31 C and 73 atmospheres does not mean it is useless. Extractions are done with liquid solvents all the time. Do you have to heat water past 370 C and 20 Mpa to make tea or chicken broth? I would assume that carbon dioxide is a good solvent as a liquid too, and I wouldn't be surprised if nitrous oxide might work as well. My info about the critical point, triple point, and vapor pressure curve was simply to answer the question of what pressure to expect at different temperatures. Dense CO2 above 31C=Supercritical. Below -56C=Dry Ice. Anywhere between= liquid, with a vapor space above it, and a pressure depending on the precise temperature. By the way, you can also make liquid or supercritical carbon dioxide by buying dry ice and putting it in a sealed container (and heating it if necessary):
https://www.youtube.com/watch?v=-gCTKteN5Y4
I also suppose that if you only had acess to a cylinder of carbon dioxide without a dip tube, you could put the extraction chamber in an ice bath, and let it condense gaseous CO2 under pressure. A direct transfer of liquid (maybe invert the uncooperative cylinders?) would definately be better though.
Just be carefull to select a container that can easily contain the pressure at your operating temperature; A dry ice bomb full of weed is doubly illegal some places

.

[Edited on 14-3-2018 by Vomaturge]

[Edited on 14-3-2018 by Vomaturge]

NEMO-Chemistry - 13-3-2018 at 16:16

I cant argue one way or other, i doubt your info but equally its something I have seen. I have given every detail i can remember and the most significant one i was told was to make sure the CO2 tube inside the bottle goes to the bottom.

As the cream whipping stuff, that is pure hearsay and not something i have witnessed.

Apparently there is alot of d-limonene in old car tires!!! I cant remember where i read that but will track it down. The only thing that sticks in mind was deciding i would only use the stuff i extracted from orange peel!

Thinking about the CO2, freeze drying is done with CO2 in a vacuum isnt it? when you let the pressure back in the stuff evaporates and leaves the material dry.

So if it takes water straight out of strawberries etc, then why wouldnt it extract from the erb?

Having said all that, there was no vac pump when i saw it done, but its a kind of side thought.

[Edited on 14-3-2018 by NEMO-Chemistry]

Swinfi2 - 13-3-2018 at 18:22

Furthermore there is a recrystallizing method referred to as "winterization" using ethanol. I also know this is being done to the extract after the limonene is removed.

Winterization is the process used to remove plant fats from the extracted material, the terpenes and canabanoid solubilities aren't too effected by temperature but filtering while as cold as possible takes out plant fats. Then distil your ethanol back off.

I've heard this makes a product suitable for use in vape pens etc. which would be healthier than mixed combustion products.

NEMO-Chemistry - 13-3-2018 at 19:15

Quote: Originally posted by Vomaturge

I don't think it can get "critical" unless it is at least 31 C and 73 atmospheres:
https://en.wikipedia.org/wiki/Supercritical_carbon_dioxide
As far as what pressure will liquify it at cooler temperatures, this calculator might help:
http://www.peacesoftware.de/einigewerte/co2_e.html
Bear in mind that below about -56 C, pressure will only solidify CO2, but not liquify it.

Edit: I might add that if there is liquid CO2 present (i.e. a denser water-like phase that settles to the bottom of the pressure chamber), than it's probably NOT supercritical. This might be more of a technicality, though. Just because CO2 cannot work for a supercritical extraction below 31 C and 73 atmospheres does not mean it is useless. Extractions are done with liquid solvents all the time. Do you have to heat water past 370 C and 20 Mpa to make tea or chicken broth? I would assume that carbon dioxide is a good solvent as a liquid too, and I wouldn't be surprised if nitrous oxide might work as well. My info about the critical point, triple point, and vapor pressure curve was simply to answer the question of what pressure to expect at different temperatures. Dense CO2 above 31C=Supercritical. Below -56C=Dry Ice. Anywhere between= liquid, with a vapor space above it, and a pressure depending on the precise temperature. By the way, you can also make liquid or supercritical carbon dioxide by buying dry ice and putting it in a sealed container (and heating it if necessary):
https://www.youtube.com/watch?v=-gCTKteN5Y4
I also suppose that if you only had acess to a cylinder of carbon dioxide without a dip tube, you could put the extraction chamber in an ice bath, and let it condense gaseous CO2 under pressure. A direct transfer of liquid (maybe invert the uncooperative cylinders?) would definately be better though.
Just be carefull to select a container that can easily contain the pressure at your operating temperature; A dry ice bomb full of weed is doubly illegal some places

.

[Edited on 14-3-2018 by Vomaturge]

[Edited on 14-3-2018 by Vomaturge]

Legality has nothing on the trauma you would suffer from the loss of weed at the prices it goes for around here!

Dont laugh but there is a video from ages ago, its about a guy called jimmy (i am not making this up), who went around food factories and then in his barn tried to replicate things like making rice crispy cereal things. The snap crackle and pop ones...anyway

He did freeze dried peas with a leaf blower and CO2, i also remember a vac chamber he bodged up.

edit as luck has it i found the write up but no video. He did this on TV but it seems the actual video is long gone.

Anyway this is an excerpt from the program blurb

"In this programme Jimmy tries to copy some of the methods food companies use to preserve food to make it safe to eat weeks, months or even years after it is produced. Why do peas have to be frozen within hours of picking and why is factory freezing quicker than home freezing? Jimmy also attempts to suck all the water out of strawberries so they can be added to a box of breakfast cereal. Jimmy copies the factory preserving processes using a leaf blower, a vacuum cleaner, two dog bowls, and the flexible hose from an extractor fan."

http://www.bbc.co.uk/programmes/b00nvg98

shame i cant find the video, from memory considering it was a barn bodge he did pretty good!

Myself i am more dubious of Nitrous Oxide, but it was just something that came up in a chat and not something i have seen.

To clarify i do alot of plant extractions (legal ones) for essential oils for soap making and all sorts of stuff, its mainly what i am interested in, and was the reason I went to this place to see how they did it with CO2.

As it turns out I havnt ever used it myself, but I have used Butane a good few times to get various plant oils out. For the kind of plants i study its rarely worth doing with Butane, and nothing gets consumed from the extraction.

Tsjerk - 14-3-2018 at 00:15

So in theory, this should work?

Use a metal pressure chamber with an over pressure valve. Make a metal rack lifting the plant material to be extracted from the bottom, fill the chamber with material and dry ice; let it warm up.

Somewhere in the process, the CO2 will become liquid, maybe depend on the pressure, which will extract the material, leaving extract at the bottom of the chamber?

A tube with a collection chamber at the lowest point of the chamber would be more effective in collecting the extract, and will make the metal rack unnecessary.

Apparently you would need a pressure of 5.1 atmosphere, where at a temperature above -56 degrees Celsius CO2 will become liquid. Lets say you set the over pressure valve at 6 atm, and the whole thing should become -56 by itself at some point. 6 atm sounds doable, also in combination with a collection chamber.

Am I right?

Plus an autoclave/pressure cooker needle valve

[Edited on 14-3-2018 by Tsjerk]

Fulmen - 14-3-2018 at 04:00

From what I could find with a quick search the solvent properties of CO2 and sCO2 varies with temperature and pressure. Higher temperatures seems to extract waxes, terpenes and other non-active compounds as well as the primary product, so depending on your goal sCO2 might not be the best option.

It should be possible to build a simple extractor that could extract using both methods. Imagine two chambers (A&B) connected at the top with a U-bend and a valve. The sample is loaded into the chamber A and filled with liquid CO2. For a subcritical (liquid) extraction one would simply let the liquid drain into chamber 2, close off and depressurize.
For a supercritical run chamber A would be heated to SC conditions, the extract could then be transferred to chamber B simply by cooling it. This has the added benefit of eliminating the need for filters since the medium can be transferred with the chambers in the upright position. Adding a third chamber would allow you to separate out the subcritical-soluble products.

Tsjerk - 14-3-2018 at 04:30

Ok, ok, And how do you suggest obtaining liquid CO2 in this scheme?

Fulmen - 14-3-2018 at 04:54

You could use something like a Sodastream canister or charge the chamber with dry ice. You could even make a separate tank for liquefying CO2 from dry ice.

Bert - 14-3-2018 at 05:24

Or you could go over to Airgas and just rent a tank/buy a fill as needed. Be sure to specify a tank with a DIP TUBE, as you want liquid, like someone making CO2 fog, not a top take off tank for GAS, like a soda or beer dispenser.

And make sure the (occasionally) ignorant dude on the dock at Airgas understands the difference, nothing more embarrassing than a whole stadium worth of foggers randomly failing to output because a good % of the CO2 tanks shipped to you are either top takeoffs mislabeled as being liquid supply, or the dip tube came unscrewed/corroded off years ago and is rolling around in the bottom of the tank, but no customer noticed or cared before your crew rented them.

[Edited on 14-3-2018 by Bert]

Tsjerk - 14-3-2018 at 05:26

Hmmm, But what would then be the difference between my setup and the two/three chamber setup? Excapt for the fact that there are different chambers?

The liquid , not critical, CO2 would be between around and -56 and -50 (or so) degrees, which would, I guess, minimize secondary extraction of compounds.

Bert - 14-3-2018 at 05:44

I believe, from the general tone of this discussion, that the home extraction community is headed towards experiencing mechanical explosions due to jury rigged CO2 extraction chambers implemented by folks with no engineering background to properly spec the parts, in place of the previously frequent butane vapor explosions and fires...

Pardon my cynicism. I am old enough to remember when hash oil cooks blew up there apartment building PROPERLY- with 95% ethanol and diethyl ether used in rooms with ordinary, sparking light switches, basements with gas hot water heater pilot lights & etc.

[Edited on 14-3-2018 by Bert]

Tsjerk - 14-3-2018 at 06:07

I wasn't exactly planning on ending up with stainless steal in my forehead.

I can't weld and am not planning on learning. I'm actually looking for a professional doing this for me as I see a big market for CBD oil, planning to sell to re-sellers.

My rig would have a needle valve pressure release, and is capable of running completely unattended. Free from any physical manipulation between the point of loading dry-ice until being back at RT, when back at RT the needle valve will be used to release residual pressure.

Bert - 14-3-2018 at 06:56

Dry ice is a "value added product". They chill it to freezing by boiling off some of the CO2. It costs more per lb. than the liquid, which is also easier to handle- Pipes. Valves. Pumps. Not moving chunks of dry ice by hand, inefficient of time and labor, dangerous due to frostbite and inevitably exposing it to atmosphere and FREEZING ATMOSPHERIC MOISTURE ONTO THE DRY ICE SURFACE TO CONTAMINATE YOUR PROCESS, freeze inside your device and block the pipes, extract the water soluble crap you don't want and generally fuck everything up.

Your entrepreneurial spirit is admirable, but

"A man's got to know his limitations"

Hire a process engineer, or at least an experienced steam fitter.

Tsjerk - 14-3-2018 at 07:07

I think dry ice is easier to handle as with the dry-ice I won't need any pipes/valves/tubing. Just open the lid, dump it in, and wait until it evaporated. It is also easier to get and transport as I won't need to keep anything pressurized. Only the extractor will be pressurized at some point, but not at any point during me handling it.

Fulmen - 14-3-2018 at 07:20

Bert: You raise some valid concerns, building the equipment I'm describing isn't for the average amateur. But I know I'm not the only one here with the skills to do so.
As for the cost, it all depends on your sources. I wouldn't consider dry ice if I could get liquid cheaper, but for a couple of tests the cost of buying/renting a tank could cost more than a pound of dry ice.

happyfooddance - 14-3-2018 at 07:24

I believe, from the general tone of this discussion, that the home extraction community is headed towards experiencing mechanical explosions due to jury rigged CO2 extraction chambers implemented by folks with no engineering background to properly spec the parts

[Edited on 14-3-2018 by Bert]

I agree. There is no way you are going to jury rig a supercritical CO2 extraction set-up without creating a bomb.

Search for QWET or QWISO extraction, you will find techniques that give a better product using safer and more food safe materials.

Either way, you will want to experiment with a variety of solvents.

Every extraction that minimizes polar compounds is carried out at low temperatures. Even butane extractions that are done at r.t. (under pressure) will look like green tar (not gold like you want). Alcohol extractions should be done in sub-zero temps, a little crushed dry ice can help a lot (but don't use too much!)

Distillation requires a very strong vacuum, under 1mmHg, and a Kugelrohr (or fakelrohr) set-up works best.

The big challenge of extraction is minimizing pick-up of chlorophyll. Chlorophyll is a strange compound; it clumps together and can bind itself to non-polar and polar substrates quite tenaciously.

Edit: I just want to add that, although cannabis extraction might be legal in your jurisdiction, putting CO2 in sealed containers other than specified CO2 tanks probably is.

[Edited on 3-14-2018 by happyfooddance]

Tsjerk - 14-3-2018 at 10:00

I'm also looking for high purity pentane, but I'm still interested in this liquid CO2 thing. We stopped talking about critical CO2 some time ago as that is indeed not doable at 73 atmosphere. 5-6 atm sounds doable to me though, with a rig welded by a professional.

https://youtu.be/o2aIUemy9Xw

This is in a simple plastic screw top tube

[Edited on 14-3-2018 by Tsjerk]

Fulmen - 14-3-2018 at 10:22

Tsjerk: Regardless of pressure you need a vessel designed for that pressure (plus a generous safety factor). Don't forget that low temperatures can affect material properties. Fortunately stainless steels tend to have good cold properties, but you still need to factor this into the design.

Tsjerk - 14-3-2018 at 10:25

Thanks for thinking along! I'm thinking about this in design! I'm discussing with a professional welder with experience in pressure equipment as we speak.

happyfooddance - 14-3-2018 at 10:38

I would imagine that at only 5-6 atm, your CO2 will be too cold to extract anything. Remember what I said before about adding only a little dry ice to chill your alcohol to sub-zero temps? Too cold and even alcohols won't dissolve thc. I highly doubt that CO2 would at the temperatures you are talking about.

If it does it will take a lot of time and multiple extractions. Yields will be poor. More likely than anything I think you will end up with a chunk of plant matter frozen in a block of dry ice, which you will have to let thaw: which, by the time it does thaw will have condensed lots of water and left you with green soup.

You are not the first or the five thousandth person to attempt to work with CO2 in this fashion. Best of luck though! I would say to wear your safety goggles, but I doubt they would do anything to help in the case of mechanical failure of your apparatus.

Tsjerk - 14-3-2018 at 23:10

OK, we will see what happens. My guess is that -56 degrees Celsius should be enough to get the lighter oils out, which are the aim of the extraction (I''m aiming for CBD, not THC, although those should behave similarly). The extraction time can be made quite long because it is depending on the heat input.

I'm not too worried about water condensation as the system is closed, as long as the plant material and dry ice is dry enough it should be fine.

safety; I will put the chamber behind a screen after closing it. and let it run over night. This should give enough time to heat up. I'm still thinking about a way to release residual pressure remotely.

Tsjerk - 15-3-2018 at 05:42

I'm now working on a simple tube/valve setup made out of 316 stainless.

happyfooddance - 15-3-2018 at 09:37

OK, we will see what happens. My guess is that -56 degrees Celsius should be enough to get the lighter oils out, which are the aim of the extraction (I''m aiming for CBD, not THC, although those should behave similarly). The extraction time can be made quite long because it is depending on the heat input.

I'm not too worried about water condensation as the system is closed, as long as the plant material and dry ice is dry enough it should be fine.

safety; I will put the chamber behind a screen after closing it. and let it run over night. This should give enough time to heat up. I'm still thinking about a way to release residual pressure remotely.

Lol.

-56 will get nothing out. CO2 at -30 will get nothing out. CO2 at 0 C° will get nothing out.

Not worried about water? You clearly don't understand what I was saying. You can semi-close the system and if it maintains a slight positive pressure, you can exclude water. But the point is, a brick of dry ice won't extract anything. You have to evaporate the CO2 and try again. After you try this and come back and read what I am saying, maybe you will understand.

Safety: placing it behind A SCREEN?!?

You are kidding yourself and heading for hurt.

Residual pressure? It is nothing like "residual". It is more like, increasing rapidly pressure.

Why don't you do a little more research, because many people have tried what you are attempting. The research is less work than constructing an apparatus which

is headed towards experiencing mechanical explosions

Pardon my cynicism.

[Edited on 14-3-2018 by Bert]

Tsjerk - 15-3-2018 at 11:36

Dude? What is your problem? I didn't read all your posts, but the once I did read are all this negative shit like you spill here.

Do you have a clue about what I mean with a screen? Apparently not as you think I'm stupid. I used to make high and low explosives, I know what an explosion can do, I can perfectly imaging what a steal vessel at high pressure can do, I don't underestimate it. Don't worry.

Residual is relative. My over pressure valve can handle 650 liters of gas per minute. You don't have a clue about the size of
my apparatus, so you don't know how much it will have to handle. Don't make assumptions.

Semi-closed? My apparatus is completely closed with a high over pressure, which you could have known if you would have read what I said and looked at my ugly drawing. Where is the water coming from?

Did you see the YouTube video I linked too? A brick won't extract no, the idea is to make liquid CO2. It is not going to evaporate before doing so, and I'm not going to try doing so, thank you for suggesting though.

Do you have references saying cold CO2 doesn't extract? I can't find them, please enlighten me. I like using references when stating something not commen knowledge, as you can see from my posts in the past.

Vomaturge - 15-3-2018 at 12:03

The word screen can mean many things. "a windscreen" "a computer screen" "a privacy screen of trees" Tsjerk doesn't mean fine mesh... I hope. As for residual pressure, he has already stated his intent. He wants a pressure release valve that will let off at 6 atmospheres (or some other pre-determined pressure lower than the vapor pressure of carbon dioxide at room temperature). As the dry ice heats up, the pressure will rapidly build, allowing the dry ice to melt. When the pressure gets high enough to open the valve, the liquid CO2 will start evaporating and escaping. The extract is supposed to stay in the chamber, assuming that the extraction worked to begin with. Once all the CO2 boils off, and the chamber has come up to room temperature, the safety valve should stop venting. The chamber will still have gas under pressure. This is the "residual pressure" that has to be vented before opening the chamber.
For some reason I to would expect extractions to be ineffective at extremely low temperatures. I know I already said that carbon dioxide may not have to be supercritical, but I was more thinking along the lines of 0C, 30 something atmospheres or 20C, 50ish atmospheres. But again, I have no proof that this will work better. The liquid CO2 extractions I saw on YouTube did not show the pressure or temperature.
Of course, any increased pressure will make it harder to build a pressure vessel, and will lead to a worse explosion if it fails. I am not sure whether people should try this and be very careful, or if they should not try it at home at all. A while back, I found this story about a serious brain injury from a bottle of ginger ale that overpressurized:
https://survivingtraumaticbraininjury.com/tag/soda-can-explo...
If it was a re-used plastic bottle, it could not have held more than a liter or two of carbon dioxide gas and water with CO2 in solution. The pressure could not have been more than 10 or 15 atmospheres in a plastic soda bottle. But that was enough to do permanent damage. I have heard people say that a container of liquid rupturing is less dangerous than a container of gas, because it won't expand violently once the containment is gone. But, with a container full of liquid carbon dioxide, the EXPLOSION WILL BE MUCH WORSE THAN WITH AN EQUAL VOLUME OF GAS AT THE SAME PRESSURE.

Just for the sake of it, lets try to see how bad. Once the container breaks, liquid CO2 will spray out into the surroundings. At the triple point of 217K, 5.18 bar, the latent heat of fusion of the liquid is 197 j/gm, and the latent heat of sublimation is 571 j/gm. The density and molecular weight are roughly 1.1kg/L, and 44 g/mol, respectively:
https://www.pacificdryice.com/physical-properties/
based on the heats of fusion and vaporization, it is clear that WITHIN MILLISECONDS, ABOUT 34.5% OF THE LIQUID WILL VAPORIZE, (around 8.6 mols of gas from a liter of liquid) and the remainder will freeze, without the pressure or temperature changing at all. 30 liters of gas, still at around 5 atmospheres and -56C are almost instantly released from a single liter of the fluid, and this freeze-boil-expand process releases around 15 kilojoules of mechanical energy. I would say that it takes between a gram and ten grams of chemical explosives to do the damage of a liter of CO2. The gas is still at 5 atmospheres at this point, and will continue to expand and cool, although how much it can adiabatically expand before it just starts condensing into dry ice is hard to estimate. Now, If the liquid CO2 were warmer than -56C, more of it would evaporate initially, and it would be at a higher pressure, causing much more damage. That was long. Sorry. I just had to try to quantify this.

A more important calculation: (cost of apparatus blown up+cost of court fees, jail time, fines, etc for explosives and or drugs+ cost of doctor bill because you partially blew yourself up+cost of cannabis you blew up)(shitty quality of life because you're in trouble with the law+shitty quality of life because you blew up your stash of weed+shitty quality of life because you partially blew yourself up)(the tremendous indignity and embarassment of this whole debacle)= how bad an exploding extractor could be.

Still a bit better than a scorching hot butane explosion-extraction:
http://registerguard.com/rg/news/local/36308727-75/feds-argu...

Edit: I didn't do all of those stupid "vaporization" calculations just to scare people out of doing this. I had done most of them for other reasons a year or two ago (and no, I didn't blow anything up). In some ways, the results are encouraging: a small CO2 extraction chamber rupturing might be hazardous, but not insurmountable. Trying it does not have to be an incredibly stupid or wreckless thing. If you did it in a bottle held in the hand, and tried to control temperature and vapor pressure by tightening and loosening the cap, now That would be really stupid. But if you have a strong chamber with a safety valve that's much better. Tsjerk, I think you are pointed in the right direction safety wise, thinking about putting the whole setup behind a, ahem... fragmentation suppression barrier. You know that there's a good chance the thing will explode, and are finding ways to deal with this reality. That's the way it will have to be for any amateur or "DIY professional" unit. Now, depending on what you're extracting, how much, where you are, etc., we might have to get pretty creative with explosion fail safes. A way to recover product post-accident would be really nice, and a way to surpress sound and pressure waves might be crucial in some installations, like in an apartment (hypothetically). I don't plan on extracting any cannabinoids, but I am captivated by the idea of using carbon dioxide as a solvent. That's the main reason I'm part of this discussion.
Happy extractions!

[Edited on 15-3-2018 by Vomaturge]

[Edited on 15-3-2018 by Vomaturge]

Tsjerk - 15-3-2018 at 12:04

[Edited on 15-3-2018 by Tsjerk]

happyfooddance - 15-3-2018 at 12:20

Dude? What is your problem? I didn't read all your posts, but the once I did read are all this negative shit like you spill here.

Do you have a clue about what I mean with a screen? Apparently not as you think I'm stupid. I used to make high and low explosives, I know what an explosion can do, I can perfectly imaging what a steal vessel at high pressure can do, I don't underestimate it. Don't worry.

Residual is relative. My over pressure valve can handle 650 liters of gas per minute. You don't have a clue about the size of
my apparatus, so you don't know how much it will have to handle. Don't make assumptions.

Semi-closed? My apparatus is completely closed with a high over pressure, which you could have known if you would have read what I said and looked at my ugly drawing. Where is the water coming from?

Did you see the YouTube video I linked too? A brick won't extract no, the idea is to make liquid CO2. It is not going to evaporate before doing so, and I'm not going to try doing so, thank you for suggesting though.

Do you have references saying cold CO2 doesn't extract? I can't find them, please enlighten me. I like using references when stating something not commen knowledge, as you can see from my posts in the past.

Research it yourself.
I don't give a fuck if you blow yourself up, willingly, or stupidly. Have fun. You can talk shit on me and my posts, but if you look carefully, I only post to help other people, usually from hurting themselves. How many questions have I asked, how many threads have I started. I'll help you out. 0.

Tsjerk - 15-3-2018 at 12:23

I didn't think you would worry about me hurting myself.

Why do you try helping people if you don't care about them? Does it make you feel better about yourself?

I will let you know how my experiment works out.

[Edited on 15-3-2018 by Tsjerk]

aga - 15-3-2018 at 12:28

Welding is Fun ! Definitely worth learning.

In any event, testing pressure apparatus isn't too difficult. Slightly dangerous, but not difficult.

https://es.aliexpress.com/item/Hand-tool-manual-pressure-tes...

Tsjerk - 15-3-2018 at 12:28

@happyfooddance; don't like speculation while pretending you are not. I used to peer-review articles, including reviews, among others for Nature Reviews. By my hand articles got rejected because of speculations, I just hate it. Your posts have a very strong penetrating speculation smell around them.

[Edited on 15-3-2018 by Tsjerk]

happyfooddance - 15-3-2018 at 12:28

Quote: Originally posted by Vomaturge

The word screen can mean many things.

You both are complete rookies, which is apparent.

happyfooddance - 15-3-2018 at 12:40

@happyfooddance; don't like speculation while pretending you are not. I used to peer-review articles, including reviews, among others for Nature Reviews. By my hand articles got rejected because of speculations, I just hate it. Your posts have a very strong penetrating speculation smell around them.

[Edited on 15-3-2018 by Tsjerk]

Tell me which of my professions are speculations. I will gladly send you pure samples of your own dumb-ass interpretations of organic chemistry.

aga - 15-3-2018 at 12:44

Chill out dudes.

No need for personal attacks etc.

All that kind of ego-crap is really boring.

Edit:

Take deep breaths, then weld some bits of scrap steel together to relax.

[Edited on 15-3-2018 by aga]

Tsjerk - 15-3-2018 at 12:50

I didn't say your posts are based on nothing, but you never give any checkable resources for any of your claims. You just say "this is true" without explanation. Also when it is not obvious what you are claiming.

Besides that you also speculate. How do you know CO2 doesn't extract at low temperatures? Did you try it? Did you read it? Is it Common knowledge?

S.C. Wack - 15-3-2018 at 13:01

What makes you think liquid CO2 is a solvent at all? By extension this means you think industrial supercritical extractors are fools who could just be shaking liquid CO2 in a pressure vessel.

Tsjerk - 15-3-2018 at 13:08

https://www.sciencedirect.com/science/article/pii/S026087749...

https://youtu.be/o2aIUemy9Xw

OldNubbins - 15-3-2018 at 13:32

This guy appears to know enough about what he is doing to still be alive.

Superitical CO2 - in plastic! WOOOOO! Get the pitchforks!

S.C. Wack - 15-3-2018 at 13:39

Subcritical extractions are known but the extraction power is not good. Data at higher pressure here.

Sustainable Production of Cannabinoids with Supercritical Carbon Dioxide Technologies

Hélène Perrotin-Brunel.

Attachment: H.Perrotin-Brunel-PhD_thesis-final_version.pdf (2.9MB)
This file has been downloaded 501 times

Sidmadra - 15-3-2018 at 14:25

I find this a little funny and felt that it needs to be pointed out, since nobody has done so in the last 3 pages - people are arguing about CO2 extraction, and have been posting about it since the first page, when that isn't even what OP was asking about.

It was pretty clear to that he was asking about purifying cannabinoids (separating out the low-mid BP terpenes from the high BP cannabinoids), POST-extraction, since he was talking about short path distillation. You know, taking the sticky wax and refining it into a nice white powdered THC/CBD/Cannabinoid mixture. His entire first post is about distillation and boiling points, which being a chemistry topic works here. There isn't any mention or question of the extraction process, yet people are here arguing over CO2 extraction.

Quote: Originally posted by S.C. Wack

What makes you think liquid CO2 is a solvent at all? By extension this means you think industrial supercritical extractors are fools who could just be shaking liquid CO2 in a pressure vessel.

What do you mean? CO2 is a solvent in this application... Supercritical CO2 is good solvent in that it dissolves a wide range of compounds, regardless of their solubilities. A quick google search can reveal hundreds of pages on its ability to act as a solvent, and "green replacement" for many other solvents. If it wasn't acting as a solvent then it wouldn't do anything to extract the high BP cannabinoids.

These "industrial supercritical extractors", COULD shake liquid CO2 in a pressure vessel, but after drainage, there would still be desired compounds left behind in the material. Shaking it makes little sense as an extraction technique, when you could use a continuous extractor and get a more thorough extraction with FAR more ease. You can also get away with having a lower ratio of solvent:plant material.

Imagine you have 500g of plant matter, and to do a complete batch extraction, you might need 20L of solvent because of the low solubility of the compounds. Or, you could use a loop extractor that recycles the solvent, like a Sohxlet, and get away with just using 500ml of solvent.

[Edited on 15-3-2018 by Sidmadra]

S.C. Wack - 15-3-2018 at 14:49

We've moved on from this limonene stupidity. I said liquid CO2. Supercritical CO2 is not liquid. When this homemade process with liquid CO2 has pumps and/or many cycles like the 65 atm. Soxhlet of Tsjerks article it might extract something.

Sidmadra - 15-3-2018 at 15:02

Quote: Originally posted by S.C. Wack

I feel like we're splitting hairs here... but I definitely wouldn't just outright declare it's not a liquid, as supercritical CO2 is in a fluid state and dissolves compounds like a liquid, even though it's not technically in liquid form.

https://en.wikipedia.org/wiki/Supercritical_fluid

"A supercritical fluid (SCF[1]) is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid."

https://en.wikipedia.org/wiki/Supercritical_carbon_dioxide

"Supercritical carbon dioxide (sCO2) is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure."

.... and I'm not sure why we moved on from the Limonene thing. Practically nobody tried to answer OP's question except for one or two people. This thread has mostly just been an arguing place of people debating about CO2 extraction.

happyfooddance - 15-3-2018 at 15:29

I have a hard time thinking that I am "arguing" at all. I am just trying to keep someone from hurting themselves.

S.C. Wack - 15-3-2018 at 15:30

I feel like we're splitting hairs here... but I definitely wouldn't just outright declare it's not a liquid

It's most very definitely not a liquid and it's not splitting hairs. There really is a huge difference between the two forms in both utility as a solvent and physical form.

There isn't a reason to use limonene as a solvent. Because someone else has done it isn't a good reason.

Corrosive Joeseph - 15-3-2018 at 16:23

Please guys, no bitchin'...........

Slightly off-topic, but what I have 'heard' -

All brands of lighter gas gave a similar golden oil tinged with brown and a barely discernable hint of green.

One particular brand gave a most beautiful golden oil that was far more potent than any other.

Once the oil is collected in the bottom of a glass bowl, it is placed on the (just switched on) steam bath and dissolved in about ten times it's volume of pure EtOH.
This dissolves both oil and resudial gas (and even shitty ethyl mercaptan) and the hydrocarbons and ethanol are driven off as SLOWLY as possible.

Repeat this alcohol wash 2 or 3 times.

Now for 'winterization'. Dissolve the oil in enough EtOH to fill a glass bottle with a good seal.
Place in the freezer, packed in a crushed ice/table salt mix. This will bring temperature down to about -20c

The plant waxes will coagulate and fall out of solution.

Filter and then evaporate the alcohol (slowly again) to give a very potent oil.

This is the easiest way to produce a material of high quality and if the oil is to undergo a distillation it is the perfect starting material.

Butane that had been pre-chilled over night in the freezer and used immediately, produced a digusting oil that drew out far too many undesirable compounds.

NO comparison to 'room tempature' cans. Just report of the effect of temperature on solubility as touched on above.

NOTE - Even 3 alcohol washes on an oil made with evil ethyl mercaptan gas left no sulpher/rotten egg smell and that stuff is detectable below 1ppm in air. I'm not recommending anybody use this gas but only trying to showcase the efficiency of the pure EtOH washes.

I'm sure there was more but thats all I can remember for now.

[EDIT] - Nodded off on the keyboard and fired off half a post too early.
Goodnight

[Edited on 16-3-2018 by Corrosive Joeseph]

happyfooddance - 15-3-2018 at 16:30

Besides that you also speculate. How do you know CO2 doesn't extract at low temperatures? Did you try it? Did you read it? Is it Common knowledge?

Sometimes. Experience. Yes. Yes. Yes.

Fulmen - 16-3-2018 at 00:33

Can we take a step back and discuss this in a civil manner?
Happyfooddance: Do you claim that cold liquid CO2 won't extract THC specifically or that it doesn't work as a solvent at all? This video does suggest that it could work: https://www.youtube.com/watch?v=o2aIUemy9Xw

A quick search for this method on THC did not give any results, but that really isn't conclusive evidence of anything. And while one should never underestimate the dangers of pressurized vessels it should be possible to do this safely without too much effort.
The triple point for CO2 is 510kPa/217K, so a 6-10atm safety valve should work assuming it can handle the temperatures (-50°C).

Sulaiman - 16-3-2018 at 01:48

If the sale and/or trade of the product is not allowed,
what is the benefit of regular extraction/concentration ?
(once or twice as an experiment I understand)

I imagine that there is a significant risk of abuse rather than use with very concentrated extracts
and the side-effects of consuming the entire product are historically well documented,
but at high dosage, without (possibly) intrinsic 'antidotes' to some side-effects,
there will be new potential risks.
=======================
regarding butane-in-a-can as a solvent, to check for non-volatile contamination
squirt an inverted can into a clean borosilicate beaker,
(thermally isolated from external thermal conductors such as liquids and solids),
allow to evaporate, then check for residues.
(outdoors, upwind, with no ignition sources downwind)
Then do the same for any other potential solvent.
.......................
I find it difficult to believe that butane would leave more residue than limonene which has a much higher b.p.
I can imagine butane residues being more sensitive to detection than limonene,
due to the molecular similarity between limonene and THC,
and the b.p. difference between butane and the product..
......................
anecdotal: I use transparent plastic cigarette lighters, after 10's refills per lighter I have never seen any residue, liquid or solid.

Tsjerk - 16-3-2018 at 02:30

Quote:

If the sale and/or trade of the product is not allowed,
what is the benefit of regular extraction/concentration ?
(once or twice as an experiment I understand)

I'm aiming for CBD, not THC. CBD is a big hype now and as long as the concentration of THC in the end product is lower than 0.2% Dutch law has no problems with the sell of it.

CBD is diluted to 4- 10% in for example vegetable oil.

There are breed of Cannabis sative which are very low in THC but high in CBD.

CO2 extraction is a big plus when selling the product for consumption. I don't know how contaminated butane extracts really are, but when selling CO2 extracts are way easier to get rid of.

[Edited on 16-3-2018 by Tsjerk]

Mister E - 16-3-2018 at 02:34

Quote: Originally posted by Swinfi2

Furthermore there is a recrystallizing method referred to as "winterization" using ethanol. I also know this is being done to the extract after the limonene is removed.

You're quite correct. Winterization is a recrystalization of plant fats to separate them rather than a recrystalization of the THC.

Mister E - 16-3-2018 at 02:53

Quote: Originally posted by Sulaiman

I find it difficult to believe that butane would leave more residue than limonene which has a much higher b.p.
I can imagine butane residues being more sensitive to detection than limonene,
due to the molecular similarity between limonene and THC,
and the b.p. difference between butane and the product..

Yes, by all accounts it's easier to remove butane than limonene. This is not about ease of extraction.

This is about residual taste. Butane can make some very sensitive. That's why the advent of butane less pipe lighters (hemp wick)

I wonder most about the true BP of THC and other cannabinoids. I guess I'll know better by next week.

Thanks for actually following my intent of this post, to talk about cutting edge extraction techniques rather than just arguing how to do the same butane and CO2 extractions that were perfected close to a decade ago.

Mister E - 16-3-2018 at 02:56

I find this a little funny and felt that it needs to be pointed out, since nobody has done so in the last 3 pages - people are arguing about CO2 extraction, and have been posting about it since the first page, when that isn't even what OP was asking about.

It was pretty clear to that he was asking about purifying cannabinoids (separating out the low-mid BP terpenes from the high BP cannabinoids), POST-extraction, since he was talking about short path distillation. You know, taking the sticky wax and refining it into a nice white powdered THC/CBD/Cannabinoid mixture. His entire first post is about distillation and boiling points, which being a chemistry topic works here. There isn't any mention or question of the extraction process, yet people are here arguing over CO2 extraction.

Yup, thanks for trying to bring it back on topic. I hope once I'm running and start posting results maybe people get involved in the conversation I wanted to have.

Bert - 16-3-2018 at 04:18

Quote: Originally posted by Sulaiman

OK, let's talk about the OP topic, limonene for use as an extraction agent of the target substances.

But let us discuss the whole enchilada, there is more in play here than TASTE. Hemp wicks? Forsooth!

Yes, as an entrepreneur pushing, er, I mean SELLING the extracted product/commercial extraction equipment, all that matters is market acceptance. Taste would matter there.

I am more concerned with the systemic effects of the unintended consequences.

Every time I see something with an aromatic structure headed for the lungs, especially if it's going to be heated, oxidized, polymerized or otherwise altered on the way there? I wonder what is really eding up in those nice pink alveoli.

So what are the pyrolysis products of this aromatic solvent? How are these chemicals biologically active? Anything teratogenic? Tiny particles going all the way to the alveoli and STAYING THERE? Until and unless a phage cell gets them, and if so, how do phage cells react to this new dietary supplement?

Here is the first 10 minutes of Google research- You've been breathing limonene pyrolysis products in the air near wood kilns, apparently.

Attachment: ja_mcgraw001.pdf (212kB)
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Tsjerk - 16-3-2018 at 04:33

Maybe this thread can be split in a limonene and a CO2 thread?

Bert - 16-3-2018 at 04:53

Maybe this thread can be split in a limonene and a CO2 thread?

Could be.

What does OP think about the idea?

aga - 16-3-2018 at 06:11

ISTR that limonene is a major product from the pyrolysis of scrap rubber tyres.

Sulaiman - 16-3-2018 at 06:52

Quote:

If the sale and/or trade of the product is not allowed,
what is the benefit of regular extraction/concentration ?
(once or twice as an experiment I understand)

I'm aiming for CBD, not THC.

In that case, I volunteer my waste disposal services.

Tsjerk - 16-3-2018 at 07:09

I don't think it is easily possible to separate the two, THC won't be a waste product.

The plant material started with doesn't contain THC

Mister E - 16-3-2018 at 15:50

Maybe this thread can be split in a limonene and a CO2 thread?

Could be.

What does OP think about the idea?

I'd be happy to see the CO2 conversation separated from the limonene conversation. I was thinking last night that once my last piece comes in next week I was going to start a new thread with limonene in the title so as to try and keep it on topic a little better.

I have no issue with people talking about CO2 extraction and am curious how subcritical extraction would work for cannabinoids. Everything I've heard is that subcritical works for terpene extraction, not canabinods. I do feel there is plenty of room for both conversations but my original topic has gotten rather lost.

Mister E - 16-3-2018 at 15:53

Quote: Originally posted by Sulaiman

An important thing to note is that limonene is one of the main terpenes already present in cannabis. Almost all hash oils contain a small percentage of limonene already. Part of the whole point of using limonene as an extraction solvent is to keep it as close to the whole plant as possible.

Mister E - 16-3-2018 at 15:56

I don't think it is easily possible to separate the two, THC won't be a waste product.

The plant material started with doesn't contain THC

It is possible to separate the two however in the united states pure CBD that is sources from marijuanna is federally illegal while pure CBD sourced from hemp is legal.

Hemp of course will give you CBD but no THC. There is no need to seperate anything. Just extract all the cannabinoids and you will get a near pure CBD oil with little to no THC included.

Mister E - 16-3-2018 at 15:57

Quote: Originally posted by aga

ISTR that limonene is a major product from the pyrolysis of scrap rubber tyres.

Perhaps but the limonene most people are familiar with and able to get is distilled from cold pressed orange peel oil.

zed - 20-3-2018 at 16:44

Ummm. Everybody and his uncle, is making "hash oil" hereabouts.

Legal, in accordance with local codes, but highly illegal in residential neighborhoods. Too many exploding houses.

Since there are no federal regulations being applied, in terms of purity, there is no standard.

I have a few acquaintances, in the trade, and I trust them..... not-at-all.

Butane, can blow you off the face of the planet... And, it may leave disgusting residues in the final product.

Isopropyl alcohol 99% ala Fred Meyer, is reputed to do a good job of extraction, but complete removal might not be easy. How much residue is OK? Well, nobody knows.

Limonine makes no sense at all.

Since Oregon is an "Everclear" State... 95% Ethanol can be purchased OTC. Not cheap.

But, we know its qualities, and that a small amount of residue is probably harmless. Further, it can be recycled.

Technically, it should be possible to obtain "Tax Free" ethanol for hash-oil manufacturing purposes. But, that, isn't going to happen anytime soon.

The U.S. Federal government is tolerating, recreational pot manufacture and use in the Western States, because it would be hard to stop it. The Federal Bureau of ATF, however, isn't going to start issuing permits, allowing Tax Free alcohol use, to manufacturers who are clearly violating Multiple federal laws.

Sidmadra - 20-3-2018 at 17:51

Quote: Originally posted by zed

Technically, it should be possible to obtain "Tax Free" ethanol for hash-oil manufacturing purposes. But, that, isn't going to happen anytime soon.

The U.S. Federal government is tolerating, recreational pot manufacture and use in the Western States, because it would be hard to stop it. The Federal Bureau of ATF, however, isn't going to start issuing permits, allowing Tax Free alcohol use, to manufacturers who are clearly violating Multiple federal laws.

I don't think the alcohol being tax free matters much. The last city I lived in, the guy running the local chemical/labglass supply store said that a huge portion of his business was for people doing cannabis extracts. He always had a couple of barrels of Anhydrous nondenatured Ethanol and said people would routinely come and buy 25L at a time. I think he was selling it for $300/25L if I remember right. In any case the tax status doesn't matter a whole lot because most of the people using ethanol commercially in this manner are almost certainly using Rotary Evaporators to recover it. This is typically the standard.

As interesting CO2 extraction is, I think it's over hyped - only a small fraction of companies are using them, because the cost of the extraction units can be prohibitively expensive, and they usually don't allow much material to be processed at a given time. The upside is the CO2 is easy to handle, cheap, and easy to evaporate.

CO2 extraction is impractical from an industrial standpoint because of the physics limitations that make it increasingly difficult to make huge vessels that can also withstand high internal pressures. Industrially, the standard for large batch herbal extractions is, steeping the herb in a huge vat of solvent(water or ethanol), running it through a continuous centrifuge to separate out the solids, followed by running it through some sort of continuous evaporator to recover the solvent.

Tsjerk - 23-3-2018 at 10:04

Who said pipebomb again?

zed - 29-3-2018 at 15:13

Back in the day, my small California college would have loved your supplier.

We were completely OK, with paying full retail... plus tax, for our anhydrous ethanol.

But, no chemical supplier, in our Rolodex, would sell to us outright. No one was willing to collect the tax. Too much trouble.

So instead, we were required to purchase tax free ethanol. Perhaps a total of a gallon or two, per year.

This Tax-free ethanol came with a meddlesome ATF inspector, who cruised by unannounced, every few weeks, to monitor our usage.

Well, it seems we were always using "Too much", and he tormented us relentlessly, over nothing apparent. Bastards!

If you are a sizable company, with a decent regulator, tax free might be OK..

Otherwise, as always, I suggest you pay the tax, and be free of interfering demons.

PhenethylamineMachine - 30-3-2018 at 05:15

https://patents.google.com/patent/EP1385595B1/en

Interesting extraction method using heated nitrogen, carbon dioxide, helium or argon.

Tsjerk - 30-3-2018 at 08:55

I produced liquid CO2 for some time! There was a lot of really foamy solid CO2 under the plant material I was extracting. I screwed up though and couldn't maintain the liquid long enough to do some real extracting because I tried to do the whole thing without PTFE tape and two parts got so stuck without the tape I could never separate them to put tape in between them.

I could form liquid even with the heavily leaking joint, it extracted a bit of oil, but not much. I will order the two frozen parts again, as i will have to order new parts anyway because the setup in the photo is to small to extract more than three grams of material anyway.

My search for a new apartment went so well I found a really nice place before I could really accumulate enough money to pay for the deposit, so I'm a bit low on liquidity atm, so it is probably going to take some time before further experiments will be done. But hey, enough time to grow some plants.

Mister E - 18-4-2018 at 16:54

Vacuum purge going on now. I've got a thick dark viscous oil that still smells of Limonene.

Extracted quickly, no problem separating most of the Limonene back out using vacuum. I'm now certain the higher BP for THC, 514C, listed under the Dronabinol tradename at pubchem is correct and the more commonly excepted BP of THC at 157C is wrong. Some sources claim it is 157C at 0.05 mmHg but that still only works out to 428.6C.

I plan on letting it purge a little more before I use Ethanol to recrystalize the plant waxes and remove them. Reports of final product soon.

Sidmadra - 18-4-2018 at 21:22

Some sources claim it is 157C at 0.05 mmHg but that still only works out to 428.6C.

Nomographs are only a rough approximation in most cases, as the coeffecients are different for each molecule. The greater pressure/temperature difference you are attempting to approximate, the more inaccurate it can become.

May I ask why you care about the BP of THC at atmospheric pressure? You'd never be distilling it at this temperature anyways, instead always under a vacuum.

[Edited on 19-4-2018 by Sidmadra]

Mister E - 20-4-2018 at 02:22