You probably know this, but this method is used a lot in specimen preparation for SEM. It dehydrates without destroying the structure of the biological matter. The whole DIY bio movement might appreciate a video and the manufacturing of a critical point dryer if you're interested.
It's a good idea, and probably worth trying. One problem is that the glass is much more rigid than the plastic, so most of the stress will be created in the glass, even if there is a zero-clearance fit between the tubes. However, a heavy plastic liner would contain an explosion, so that's good.
I did some work with supercritical CO2 in the past, but in a regular lab, with large scale co2 pumps, really expensive equipment. It's fascinating to see basically same stuff done in a home workshop.
Gotta say Ben, you've really kicked up the quality of your experiments. I'm liking it a lot and I'd like to see you try some older ones again now that you've learned a lot.
For me you're probably the only person in the world that may use the words high-pressure ammonia, hydrogen, and blast in a sentence without making it sound very dangerous :)
Hey there, I personally made some experiments with liquid butane as a solvent. I just got a container of lighter refill gas and slowly emptied it into a test tube submerged into a cooling bath of ice and ethanol. Afterwards I used a simple coffee filter filled with a spice (chilis work realy nice for example) and poured the butane onto it. The gas in the resulting extract can then be evaporated easily by putting the container in warm water for a couple minutes. Works nice and is cheap and easy.
By "i've found" I mean I've done it, it works. I got a glass candle holder from a thrift shop (approx 1" by 2" solid glass with a 1" diameter hole), used 1/4" steel plate for the bottom and top (the bottom with an indent to hold a rubber o-ring) and four bolts to hold the whole thing together. It lost half the volume of co2 over a year due to leakage through the o-ring, but the addition of tubes for the input and output of co2 should leave it perfect for supercritical extraction.
I was thinking about this and I had an idea... Could you match the OD of a glass tube to the ID of the acrylic tube, or even a little larger and freeze it to shrink it when installing it, so you would have an internal glass protective sleeve?
You could use a two-way pressure cylinder for a rather easy pressurization! For the gas transmission just a regular SodaStream co2 cylinder will do fine, keep it upside down, so the co2 will run liquid between the cylinders. Just transfer the co2 in liquid form to doner cylinder by prefreezing it before transition enough. Also keep the receiving cylinder volume small enough, like 1dl while transmitter (Sodastream) will be 4dl(425ml).😊
You could do supercritical batch extraction in a paintball high pressure system. The tanks are designed and certified to be operated at 200-300 bars, the regulators have built-in manometers and breach valves for a sense of safety. Usually they come with a volume of 0.22 L and 1.1 L. To use them as CO2 tank for continuous flow extraction one has to use non-paintball regulators as their outlet valve is limited to about 55 bar, too low for the gas to stay supercritical.
It's the solvent in this process and is an ideal one for his purpose. It's not only food safe but readily evaporates at room temperature, leaving the desired product and no residue. You could use many other solvents, such as diethyl acetate, but you would need to have a roto-vap to remove the solvent at a low enough temperature to not lose some of the volatile esters and amine groups in the product.
Since you have a vacuum evaporator now, coat the acrylic cylinder with something. Aluminium deposited around 10^-3 or -4 torr should result in Al2O3 deposition, not sure, but that could be transparent. Or you could use a thin layer of gold (also transparent), for the extra blingness and inertness. Or use a inner glass liner (not pressed) bonded to the acrylic cylinder, with some UV curable glue. Normal glue is out of the question since it will never cure in the middle, 2 parts glues might.
re: glass extraction chamber It shouldn't be too difficult to melt the glass and put it into a mold. If the mold has a higher coefficient of thermal expansion than the glass, it will shrink away from the glass, allowing for easy removal.
I have always wanted to try this too! I run the Open Sun Harvesting Project which primarily provides open source software and electronics for DIY solar tracking and heliostats. I know the community would love to see some videos on this subject, and I'm sure you could do a much better job than I could. :)
why not line the inside with glass? wouldnt the outside acrylic support it from breaking? also maybe you could try having it pressurized on both sides of the glass. acrylic outside then a small space you can pressurize then a glass tube inside that. however i dont think that would be easy to regulate having the same pressure or atleast a pressure differential lower then the glass is rated for. if one dropped too low you would implode or explode the inner glass tube. i think just lining the acrylic tube with a glass tube fit tightly would be the best option but to be honest i dont know much about dealing with pressure vessels so i could be very wrong. i would love to know if i am and why
I can’t type what the dry ice vessel looks like in the comments section but I am guessing this video could have been demonetized cause of how it looks or RU-vid might have given you trouble. If you catch what I’m not say. Also I love and appreciate all the effort and work you put into your videos and just want to say thank you.
Technically, wouldn't this be liquid co2 extraction? I know I saw liquid flowing through the chamber. In a super critical state the co2 behaves like both liquid and gas, allowing the co2 to pass through material like a gas, but extract like a liquid. I'm wondering if it'd extract capsaicin from peppers. Anyone know?
Kinda works like that for de-caffeinated coffee, the caffeine and aroma compounds are removed, the caffeine extracted from that and then the aroma compounds pumped back into the coffee beans. The beans bought by your parents were likely stale, and of unsuitable quality for international sale to begin with...
I don't know if it would work but have you ever thought of coating the inside of the chamber with some non soluble resin (I'm still on the search for one) or putting a "sleeve" of glass tubing on the inside so that the acrylic wall fits around it snugly enough to support the pressure?
Google "dry ice supplier UK" you can find it. You just have to do a little more work than in the US. Plenty of places will ship to private residencies or you can check for local chemical suppliers/gas suppliers they tend to have it.
Thanks, I had a feeling it was going to be a little out of my price range, but still worth a look. I think I will end up getting one of those Chinese mini CNC mills.
If you want look at the reaction in the chamber the best material to use is aluminum oxide window (sapphire), its kind of expensive but you can probably find one online
yes its just that i thought i herd you mention this in one of your super critical extraction videos , i did do some research but some times advice from a pro cant be beat
Copper and copper alloys are incompatible with ammonia solutions and gas. In the presense of moisture the gas will corode the metal (and make a beautiful blue-violet copper ammonia complex) that is able to dissolve cellulose. - en.wikipedia.org/wiki/Schweizer%27s_reagent
Stainless steel (even high/low temperature versions) precipitates chromium at extreme temperatures- perhaps monocrystalline silicon (not doped) is the best for this. One million psi ultimate tensile (can handle the pressure), low thermal expansions/conductivity. Wafers are quite cheap- perhaps you can figure a way to use laminates to construct the vessels. Enough rows of eccentric circles could likely do it without seals.
Did you checked high pressure gas discharge lamps like stadium lights as source for high pressure gas vessels? Wikipedia says they are made for 10 to 40 Megapascal (5800 psi).
You might get a better yield on the Vanilla Bean if you were to fully dehydrate it first and then grind it up, or freeze dry it and then grind it - more surface area with reduced adhesion. Dig the work man = you're my guru toga!
Hello, I am really interested in this method. Now, I am using steam distillation method to extract essential oil. However, this method takes long time. I want to ask that if I want to build a device like your but larger amount of material and continuous working. Is it possible? Could you help me? Thank you very much
For the acrylic chamber, what kind of stainless-steel pipe would work? I was thinking I could essentially use an unthreaded version of the pipe I'm using for the CO2 chamber (schedule 80), but I don't think the surface of the pipe would be optimal for edible extractions. Under the McMaster's section of tubing > metal > stainless steel, there are no specifications of tolerable pressures other than yield pressure which I don't think refers to the same internal pressure capacity. Could you suggest some options? Great work by the way!
i actually am very interested in this question, and hope it is taken seriously. In terms of medical cannabis, working with the plant material isn't ideal because there are so many different substances. Extracting the different cannabinoids and separating them is the only way pharmacutical companies would ever do more research into the substances
You make it hard to make fun of you. Ive actually enjoyed all your videos. RU-vid needs more posters that approach their experiments AND presentations like you do. I hope you keep it up.
What about using the boiler glass tube as an insert inside of the acrylic? Pressing glass into a plastic bore sounds not-so-easy, but maybe it could be bonded into the acrylic (to take up any air space and make them intimate.)
I would be worried about thermal stress in that case, since acrylic or polycarbonate has about 10 times the thermal expansion coefficient of glass. However, maybe it would be okay. When the assembly cools from application of CO2, the acrylic would tend to shrink over the glass, creating compressive hoop stress in the glass, which would tend to cancel the tensile hoop stress in the glass from the pressure it contains. However the tensile hoop stress in the acrylic could increase a lot over the acrylic only design.
So, did you taste any of it? Did it smell good in the "lab" that day? I'd be a little concerned that some nastiness from the acrylic came along for the ride; I'm looking at you, BPA and your ilk. Anyhow, nicely done video, Ben.
Do you think Coffee producers use this method to extract aroma from one coffee source and give it to another and then sell it as a new high priced brand. I got this idea when my parents bought really low quality coffee when they had a vacation. I thought this can't really be coffee?
I replicate the test using cinnomen. Tried grinding the cinnomen at 1300psi temp 38 deg C. No oil came out, but paste like oily material stuck in samples. Then I used dry cinnomen stick. Not much luck... Must be the time to soak is also the factor
Do you know if polycarbonate holds up better to the super critical CO2? I know is holds up better to acids and the like. It looks like one could order 3" dia. rod online.
My intuition tells me that not all of what you're actually extracting is making it's way into your collection vessel. I bet if you ran some ethanol over your beans, not soak, just flush, what you'd recover would be significant. As for uses. I make nutmeg/cinnamon extract (though not as concentrated as you're doing obviously). I call it 'liquid holidays' and several drop to hot chocolate, deserts, whip cream, and so forth is amazing. Makes for unique gifts.
Why not machine the acrylic with an I.D. to match the O.D of a glass test tube? You can friction spin the test tube on for even closer matching of diameters.
I think the technique is a little different since the trichomes are on the outside of the plant. If you grind it up and put it in a can with some dry ice pieces, shake it around a bit, and then sift it over a screen all the good stuff should fall out the bottom. There are some video's of it around.
Hi, I have been watching your videos on super critical co2 and I was wondering if you had considered doing this with a shoebox compressor? I thought you could avoid the heating process and maybe get better control? I see one company seems to have made one for sale they call it the super c but it would seem that you could use the same principals you are using and make a better unit. anyways I really enjoy your videos and the range of them
I know this was a few years back, have you tried it since? I am curious if there was more surface area of the material you were running you'd get a better yield
Hi Ben. Thanks for sharing great work. I like your channel. On extraction, I have one question. How you are sure that you extracting only caffeine and not other compounds. In plants usually there are hundreds of organic compounds.
Hi Ben, My name is Emilio D'Alessandro, I'm a chemist from Italy, i am working with CO2 in near supercritical conditions and i have some troubles with viton o'ring and gaskets. I saw that in your videos you are using red o'rings, are they made by silicon or are they in EPDM polimers ? Thank you for your help, Emilio.
