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supercritical c02 extraction
- Thread starter smurfin'herb
- Start date
sure me too... and I mostly vaporize oil
I once used dirty lpg gas run through a larger active charcoal tube first, worked fine, and I tested residue first and there was none. But Ive got the recycler thing now, so there is no need for me.
to the advantages of CO2, why does one think that there are waxes in bho to any degree, and if there are, is that a bad thing? I dunno
solvent residue? the bubbles in the vials are butane you are right, and I storeed those in a vacuum and they eventually go away, and as you mentioned, I purge in larger surface area now, but.... Im not worried about a smidgen of butane being in my oil, if in fact there is. I can see some people who might, but I suspect that those same people would find some issue with CO2, such as the safety, or the eventual release of co2 into the atmosphere... just being devils advocate, cause if it could work, Id get one just for fun..
butane is not metabolized, if you breath in some, you breath it out. and if you burn it, you get co2 and water anyway.
so what would one exclude, and how and why? I dont get it. if you really wanted this it would be easier to do column chromatography on bho, almost certainly cheaper, safer, and easier.
dont make me build one dammit.
FWIW, I was involved with lab scale SFE equipment in the '90's. Supercritical CO2 shares properties of gases and liquids: it diffuses into materials like a gas and can extract fat or other materials that would be soluble in organic solvents. The solvating character can be changed by adjusting pressure and temperature, or with modifiers like methanal. There are different "recipes" depending on what you are trying to extract and the matrix.
After the SF passes through the sample, it vents back to room pressure. Whatever was in solution drips into a collection tube and the CO2 dissipates. I remember loading vessels with potato chips and watching fat ooze out into the tube. Kind of gross but you also got volatiles that smelled like french fries and made your mouth water. Conflicting reactions, for sure.
Sample vessels were stainless steel tubes, about 6" long, 3/4" diameter with ~1/4" bore. They held ~10ml and were rated to ~10,000psi, so this isn't Home Depot kind of stuff. Selling price at that time for bench top systems was in the $40-90K range. Microwave digestion came around the same time and won out, rendering SFE to small niche use. I see used equipment on-line every now and then but figure it was probably discarded for a reason (leaky pump, no parts to fix, etc.)
After the SF passes through the sample, it vents back to room pressure. Whatever was in solution drips into a collection tube and the CO2 dissipates. I remember loading vessels with potato chips and watching fat ooze out into the tube. Kind of gross but you also got volatiles that smelled like french fries and made your mouth water. Conflicting reactions, for sure.
Sample vessels were stainless steel tubes, about 6" long, 3/4" diameter with ~1/4" bore. They held ~10ml and were rated to ~10,000psi, so this isn't Home Depot kind of stuff. Selling price at that time for bench top systems was in the $40-90K range. Microwave digestion came around the same time and won out, rendering SFE to small niche use. I see used equipment on-line every now and then but figure it was probably discarded for a reason (leaky pump, no parts to fix, etc.)
Rapscalion
New member
K+ Thanks Woodye and Walter!
This has got me thinkin again.... for once.
This has got me thinkin again.... for once.
CO2 becomes super critical at under 1100psi and 100F. It doesn't have to be run at 300 bars to work on cannabis because you are not trying to leach it out of the pores, but primarily off the surface.
A 1500 psi system could be run in 300 series stainless schedule 160 pipe. End plugs like pistons with PTFE O-rings would seal the vessel while allowing quick access for cleaning and could be easily contained in a simple yoke under pressure.
I have designed a conceptual system that uses a Dewar of liquid C02 with a siphon tube. You pre-pressurize the chamber to 150 psi so that the liquid doesn't turn to dry ice when it is injected, and then use the remaining 100psi differential to force the liquid CO2 into the reaction chamber.
At that point, if you heat the reaction chamber, the C02 expands and gives you the 1500 psi needed, with a back pressure limiter venting everything above that.
Once the critical pressure and temperature are reached, the heat is turned off and the chamber vented through a stellite seated metering valve into an evaporation chamber, where the oil is deposited.
A 50 gallon Dewar of liquid C02 was $115 US last time I checked, making a cryopumped system damn cheap compareds to the pumps and refrigeration used in a typical C02 unit used to extract vegetable oil. The number of runs you would get would depend on your vessel size, but the 4" Diameter X 24" vessel that I had in mind would require less than a gallon per cycle.
I converted my simple minded AutoCad conceptual to PDF and a copy is attached:
Gray Wolf
A 1500 psi system could be run in 300 series stainless schedule 160 pipe. End plugs like pistons with PTFE O-rings would seal the vessel while allowing quick access for cleaning and could be easily contained in a simple yoke under pressure.
I have designed a conceptual system that uses a Dewar of liquid C02 with a siphon tube. You pre-pressurize the chamber to 150 psi so that the liquid doesn't turn to dry ice when it is injected, and then use the remaining 100psi differential to force the liquid CO2 into the reaction chamber.
At that point, if you heat the reaction chamber, the C02 expands and gives you the 1500 psi needed, with a back pressure limiter venting everything above that.
Once the critical pressure and temperature are reached, the heat is turned off and the chamber vented through a stellite seated metering valve into an evaporation chamber, where the oil is deposited.
A 50 gallon Dewar of liquid C02 was $115 US last time I checked, making a cryopumped system damn cheap compareds to the pumps and refrigeration used in a typical C02 unit used to extract vegetable oil. The number of runs you would get would depend on your vessel size, but the 4" Diameter X 24" vessel that I had in mind would require less than a gallon per cycle.
I converted my simple minded AutoCad conceptual to PDF and a copy is attached:
Gray Wolf
PnkFloydianSlip
Member
Sugar hash is the shit, but oh so rare..
cool...
A lot of CO2 is needed for a decent extraction:
http://www.google.com/patents/about?id=kraGAAAAEBAJ
Veress, as quoted by 3dDream before, may be perfectly correct, but the amount of CO2 used is not given in that quote. Later on in an article where Veress is given an author credit (forensicscience.pl/pfs/47_veress2.pdf), 50 minutes instead of 34 are used, and the weight of the CO2 used is 1350 times that of the sample.
A better look at the patent mentioned before:
http://www.google.com/patents/about?id=1N2oAAAAEBAJ
http://www.google.com/patents/about?id=kraGAAAAEBAJ
Veress, as quoted by 3dDream before, may be perfectly correct, but the amount of CO2 used is not given in that quote. Later on in an article where Veress is given an author credit (forensicscience.pl/pfs/47_veress2.pdf), 50 minutes instead of 34 are used, and the weight of the CO2 used is 1350 times that of the sample.
A better look at the patent mentioned before:
http://www.google.com/patents/about?id=1N2oAAAAEBAJ
I have actually seen a few lab units for sale via industrial surplus sites in the last few years. I would actually check around to see if you can find a reconditioned unit rather than trying to roll your own.
There are 6 units on ebay right now, and 2 on the various craigslists.
There are 6 units on ebay right now, and 2 on the various craigslists.
Possum
Member
they are about 100K
for the supercritical fluid extractor - i know because i have rebuilt and maintained one.
then we used a 20L buchi roto-vap i believe (another 25K with chiller and other options - i know i oversaw the purchase).
the CO2 is in pressurized tanks from say airgas or what have you. just like there is liquid CO2 in those tanks when under pressure the system does the same. then that liquid is used like any other solvent.
in the next phase a secondary solvent is used to extract the product from the CO2 before the pressure is released and the CO2 becomes a gas again. the secondary extract is collected and dried or purified further.
it's just a giant pump with all stainless tubing, fittings, and rxn vessel.
the pump pistons must be either saffire or quartz i believe - been awhile since i have built/rebuilt one.
the reason to use other solvents is because it helps with fda allowing people to ingest it. plus the technology keeps it out of the hands of diy-ers. you have to do a residual solvents test and have evidence of safety before the us govt. allows things to be medicines. butane is not really a first choice....
agree with it or not/like it or not - it's about control. and those that already have it are not giving it away.
maybe it shouldn't be that way...but it is.
for the supercritical fluid extractor - i know because i have rebuilt and maintained one.
then we used a 20L buchi roto-vap i believe (another 25K with chiller and other options - i know i oversaw the purchase).
the CO2 is in pressurized tanks from say airgas or what have you. just like there is liquid CO2 in those tanks when under pressure the system does the same. then that liquid is used like any other solvent.
in the next phase a secondary solvent is used to extract the product from the CO2 before the pressure is released and the CO2 becomes a gas again. the secondary extract is collected and dried or purified further.
it's just a giant pump with all stainless tubing, fittings, and rxn vessel.
the pump pistons must be either saffire or quartz i believe - been awhile since i have built/rebuilt one.
the reason to use other solvents is because it helps with fda allowing people to ingest it. plus the technology keeps it out of the hands of diy-ers. you have to do a residual solvents test and have evidence of safety before the us govt. allows things to be medicines. butane is not really a first choice....
agree with it or not/like it or not - it's about control. and those that already have it are not giving it away.
maybe it shouldn't be that way...but it is.
I don't know about butane being tops,It's good but I think some of the best oil I've ever puffed I think came from this method.( girl said it was O2 but from what I've read it isn't possible to extract with o2 so co2 makes more sense) Sugar hash FTW.
Used units in working shape are as little as $20k right now. It's amazing how much high end lab equipment goes on the block during a recession.
have you ever tried co2 extract?
it's crystaly and you drop a pinheads worth on a insense burner (the black carbon kind for cone incense) and then suck it up with a tube.
closest to freebasing THC you will ever get.
since they outlawed extracts using solvents, i haven't seen this at the dispensary. they called it earwax i think.
It looks like brown sugar with really big granules that are really sticky.. so good, yet to see it other than out west. I don't think the ratio of herb to oil is very good though.
