A close look at supercritical carbon dioxide CO2
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- Опубліковано 2 вер 2011
- I built a pressure vessel from aluminum and acrylic, and filled it by placing pieces of dry ice inside. The dry ice melts under high pressure, and forms a liquid and gas phase. When the vessel is heated, the CO2 becomes supercritical -- meaning the liquid and gas phases merge together into a new phase that has properties of a gas, but the density of a liquid.
Supercritical CO2 is a good solvent, and is used for decaffeinating coffee, dry cleaning clothes, and other situations where avoiding a hydrocarbon solvent is desirable for environmental or health reasons.
If you have a suggestion for what I should do with the supercritical CO2, please leave a comment.
CO2 can be liquefied in plastic bottle preforms:
• Formation of Liquid Ca...
It may be important to open the container before all of the solid melts. When there is still some solid CO2 present, the pressure will be close to the triple point. Once the solid completely melts, the pressure will increase quickly to about 750 psi depending on the ambient temp. I really doubt those plastic containers could hold 750 psi.
My first look at supercritical fluids:
• Supercritical fluids
Another youtuber interested in supercritical CO2:
• supercritical fluids
Added engineering recap and formulas:
benkrasnow.blogspot.com/2011/0... - Наука та технологія
This is awesome
i wonder what seeing this video produced....
Its crazy that im the second like to a comment from 7 years ago
Rip Grant
Wow never expected to stumble upon this comment.
F
This is an old video, but I still feel compelled to compliment you on practicing both safe science and overengineering of the design. I've seen too many instances where poorly-designed equipment failed catastrophically on the first try and the person was standing right next to the equipment. It makes me happy to see that you tested your pressure chamber at a safe distance, watching remotely.
It was a really good job. I was wondering if he would use cement blocks to surround it, just in case.
"poorly-designed equipment failed catastrophically" makes for better UA-cam videos... If you want more views, just sayin.. lol
@@rojaarkezor7185 That is ElectroBOOM's bag.
"This is an old video..."
@@SpadeNya lol
A possible solution to your O-ring problem would be to loosen your gauge off so that it bleeds off CO2 gas until you have it all together and then tighten gauge up last.
My thinking as well but also cooling off the aluminium section before closing it up.
Good idea. Let it bleed . Or c clamp , then tighten bolts.
@@ynotwebb1408 Don't you want the have high pressure inside though, as Co2 has to be above 75 psi to be a liquid? If you let the pressure out aren't you just letting out Co2 which is the equivalent of putting less in?
cryo-freeze the entire apparatus, leave the gauge ever so slightly loose, fit a solid piece of dry ice which fits perfectly, g-clamp it and bolt it down! those few seconds of CO2 venting will expel the remaining air
@@paulbiggs90 need to be fast.... it let the gas leak a bit to make the sealing more perfect
"how i built it and what i plan to do with it"
..sounds really ominous, like you're a chill supervillain
Hi!
Thank you for creating this chamber and this video, and also for helping BlueNile with his project.
You're awesome!
Beautiful design and such an amazing demonstration of phase transitions. Its awesome that it's stable and safe to handel because that type of behavior is so rare to witness. I hope to see this in real life some day!
Hey Ben, thank you for helping Nile with the pressure chamber. You are awesome!
I would like to see something floating on the liquid co2 at the time it changes...😕
I would guess it would stay suspended or sink to the bottom
Great video! Consider installing a safety relief valve on it, just in case you do place more CO2 than you should.
I would really like to buy one of these.
Just don’t tell the delivery company you are shipping a home-made plastic cylinder under extremely high pressure! :-P
Yo, you have a truly amazing and unique channel, and for what it's worth, I'd like you to know that at least one person really appreciates these. Rock on.
I would buy one of these
me too
Its practically a bomb though
@@nozumihishimatchi1880 no more so than a CO2 welding tank... Except this one has a lot less CO2.
@@nozumihishimatchi1880 nah I've worked with enough pressure vessels. The failure mode will be deformed plastic, oring failure and leaking CO2. You might get a freezer burn at worst, but explosion is not likely.
@@nozumihishimatchi1880 not even close!
my wife is also supercritical, and she can also be used for drycleaning, but i dont think she would fit in this thing. suggestions?
sixpooI were going to need a bigger boat.
what is the highest temperature ur superwife can carry out?
sixpool Here’s a suggestion: try brushing your teeth
My wife can’t be used for anything....any suggestions?
idk go to codys lab he has a pressure chamber for her
Extract the caffeine, eat it, then use the resulting energy boost to do more experiments.
you would be died afterthat
or THC
or psilicin 😌
Sounds like the beginning of a vicious circle
Just saw NileBlue's "Going supercritical." and realized I somehow missed this one from you. Glad you helped him :-)
Many thanks!
You have balls of steel. That thing is both scary as hell but infinitely intriguing, I would love to make one as a coffee table conversation starter. Keep up the awesome work!
Perhaps a small needle valve which could stand the pressure used as a temporary relief during assembly?
Certainly!
Adding a T fitting at the gauge will allow a needle or ball valve to be connected. Small high-pressure stainless steel ball valves are not terribly expensive. This also would make it possible to fill from a CO2 storage tank.
That is the coolest looking thing I have seen.
Your tool look very nice, this is the first time I see a real super critical state of CO2, beyond of what described on books, thanks for your very interesting experiment
I wonder where did you learn all these things you do. You and Cody have so much science knowledge that makes me think that a graduation in chemestry won't even get me close to what you guys know.
I love this thing! You could have kept the O-ring in place by freezing the components down to -20C, then cooling further with dry ice. If you did the final assembly in an open-top styrofoam cooler, the dry ice used for cooling components and filling the resevoir would also displace the air, I think, giving you nothing but CO2 in there.
There's also got to be some amount of CO2 (maybe you have to measure to the 1/10g or something?) that would let it reach the triple-point?
You can also extracted the the essential oils from cannabis with supercritical co2.
I like bananas
"Essential oils" ;)
Actually this is the only way to make THC e-liquid for e-cigarettes. So if you can do it, you could get rich
its not the only way. its just a common way. an even more common way is to isolate the THC fraction by molecular distillation with a shortpath distillation apparatus. 95%-99.9% thc is the same consistency as winterized co2 oil. a lot of people distill co2 oil to isolate the thc fraction. bho, pho, and ethanol extracted oil are commonly used also. the distilled thc fraction is 100% solventfree. The most well known brand of this is called "clear concentrate".
The easiest way to make Eliquid is to mix bho with a thinning agent like PEG, PG, VG or naturally derived terpenes. Most co2 oil pens are co2 oil diluted with PEG. Open vape is the most well known and its half winterized co2 oil and half PEG.
I have been since 2009. ive been making it since 2010. its vaporized, not smoked. Meaning the oils are applied to a heated surface that they boil on and the vapor is inhaled. Im not sure what youre dabbing that would burn your lungs.
Yes, i am after the essential oils. The oils in the resin glands are what gives cannabis its effect, smell and flavor.
thank you for the trial & error, & demonstration. and good luck with future experiments.
Nicely done.
Your chamber is much more elegant in appearance than one I built about 10 years ago.
A layer of transparent fluropolymer film on the inside of the window can help avoid solvent attack of the acrylic. I had used one inch polycarbonate for the window.
Supercritical fluids are fun. :)
How about a 3 way valve between the chamber and the gauge so you can vent it?
What did you do this weekend?
Oh I mowed the grass and emptied the trash.
What about you?
Oh, I built a super critical CO2 Canister
Very educational. Great work! Thank you for uploading this.
Awesome stuff. I think Nilered has this device now. Cool he (Ben) gave it to him. I am very happy to see UA-camrs helping each other out for science!
psi to bar conversion on screen would be nice.
i would love one of those on my desk
Build one in square or triangle shape and use "Peltiers" to heat it up or cool it down with a small regulator so you can just plug it in the wall or a power bank / usb. That would be cool/nice.
Thank you for making the transition to supercritical visible.
I first learned of this effect when filling a sodastream canister from a large CO2 tank used for MIG welding. I mistakenly thought that if I heated the large tank and cooled the small one that I would get a better transfer. I warmed the large tank in my car in the sun and when it was uncomfortably warm did the transfer, and noticed got worse results than when just using room temperature. I assume supercritical CO2 was created with a lower density than liquid.
The o-ring is not supposed to be pressed radially, the groove should be wide enough to allow the o-ring to expand when compressed into it's groove.
applied and cody's colab?
cody's science? applied lab? copplied scab? apody's lience? applied cody science lab, nailed it.
Also, freeze everything as much as possible while assembling. It may reduce that pressure build up. You can get plastics to machine better when frozen also and even do cool press fits with a hot and cold piece. My tips.
I came back to watch this video again because it's so interesting. Have you had a chance to do anything else with it yet? Would love to see the caffeine or even a small dry cleaning test. I like seeing the liquid from moving, it has a very otherworldly look to it.
P.S. Are you going to be at ThinkerCon by chance?
When you were machining the aluminium body on the lathe why dident you just machine the o ring grooves after the facing cuts? Then make your bolt circle on thr mill. Easy peasy
In some ways, it's easier on the CNC mill because I don't have to measure anything, and the part will come out very close to spec'd dimensions. It would probably take me longer to measure and cut it on the lathe, even though I agree that lathe-cutting the gland would leave a better finish.
@@AppliedScience You've gotta go watch This Old Tony for a bit!
Just put the meter in last. O ring problem solved.
aye
good luck getting the dry ice through that little hole
Felix Q Or do everything in a freezer. The only problem, though, is that it would have to be at a very low temperature, so his hands would freeze, but well, it’s a minor inconvenience (I’m obviously joking)
Venting is a good idea. Also, preassemble the device as much as you can and use a jig if necessary and use a driver to zip those nuts up to torque very quickly.
Alternatively, assemble the whole thing in a bath of liquid CO2. [joke]
Thank you! That is totally awesome! Should be required viewing for all mechanical engineering students.
Hello,
a few tipps:
- o-ring grooves are easier to produce on a lathe.
- you can turn your aluminum ring, screw one acrylic disc onto it. then clamp the aluminum disc in the cuck and turn the acrylic.same procedure for the second one.
- if you screw in the barometer AFTER you mounted the discs together, your o-rings will fit perfect. the overpressure will be able to flow out while you are tightening the screws.
but however: its an amazing effect, i didn't expect. thanks for the video.
Not sure I can fit my suit in there for cleaning... hahahaha
haha right
Laundry? I don't think you can get a load in there.
But in all seriousness, I haul C02 for a living, and I need this vessel in my life. :)
😂 Beverly Hills Doll Apparel Dry Cleaning...hmmm🤔i feel like it could be a thing if someone wanted it to be a thing...lol🖒
You could pre-chill the parts in your super chiller to below dry-ice temperature before assembly. There would be very little sublimation while assembling.
The pressure in the chamber is over 1000 psia, as shown by the gauge in the video.
sir can you do these experiment with liquid nitrogen
It would probably freeze the o-ring & render it too brittle to hold the seal. It would just shatter and release the pressure.
Is the liquid still there even though we can see it?.. and if so .. would i. "feel" it if i Shake this thing ( like when you feel that there is water inside a bottle when you shake it)
In its super critical state CO2 takes on the properties of both a gas and liquid. Will it slosh like a bottle of water. Not really. A rough analog might be like shaking a bottle of soapy water. Slosh a little at first, then all the water is suds and doesnt feel the same. 3:07 the phase are completly blended together leaving no density variation to feel any sloshing.
@@kreynolds1123 A nice analogy, I may steal it for future explanations!
@@onetrickhorse its a pleasure to know i contributed in a way that is appreciated.
nice bit of work, and a good demonstration of super crit man:)
Fascinating. Thank you for posting.
A few comments.
Would polycarbonate, possessing more mechanical strength be more suited than acrylic, or might you have chemical breakdown?
Do you suspect that supercritical-ness might affect your pressure gauge readings?
Is it also possible that your P vs. T curve remained relatively flat and 'inside' the supercritical range the entire time, thereby violating the gas laws and keeping the pressure low? It stands to reason that a supercritical fluid would be relatively uncompressible, so long as it remained SC.
Have you considered trying this with a two phase system, say NH3 and CO2 having both SC and/or liquid at the same time? Of course other polymers still might have to be considered if you are to see this in action.
Again. Thanks!
The acrylic should not be placed directly in contact with the liquid Co2. You should use a thin glass barrier along that is cut just a hair smaller than the diameter of the acrylic opening. Purchase a large O ring that is on the thinner side as opposed to the thicker bulky ones. In an ideal conditions the O ring should fit in the small gap between the glass outer diameter and the acrylics. When you join both sides together the pieces should be designed to press against the large O ring causing it to compress within the small space between glass and Acrylic. You may want to look into using some sort of Burst disc rated at a PSI that would in theory be below the estimated rating for the acrylic. When handling Cryogenics it can be very unforgiving. A leak or a tiny rupture won't really do much. If the acrylic becomes brittle and fails over large surface area then it will basically be a bomb.
Couldn't you have installed the gauge after torquing the bolts to prevent the o-ring from deforming?
Sounds interesting! Reminds me of the The Abyss.
Came here from Nile. U got a new sub!
Great stuff. I'd just like to see metric units too. I (as well as most of the World) don't do PSI and °F, rather N and K.
Of course, I converted the units, but scientific video should use SI units, don't you think?
Staremperor I am a scientist here in the US and I'm fine with either standard or metric. Conversions are so easy now it's not really an issue. I can see your point though.
F is absurd for sure, it was invented using what I can only describe as arbitrary reference points like the freezing point of brine and the average human body temperature... it appeals only as a convenient measure for ambient atmospheric air temperature at sea level, with a general public-friendly range between -40 and perhaps 130 at the extremes. C is far better and logical, and K is of course essential, but less easily grasped by those without a background in science. PSI is also a bit awkward, I just tend to use the 14.5:1 bar approximation for quick calcs. Bar, although not an SI unit technically, is handy as it is a multiple of the SI unit Pa, but tends to reflect better the kinds of pressures used in most applications as 1 Pa is very small. I'm not quite sure what you meant by N, since it isn't a measure of pressure, rather 1 N/m^2 is equal to 1 Pa, which is what I assume you meant. But I do agree with you, SI units on a science-related video should be standard in my opinion.
Could this be used to create a non-mechanical lens? I realize the applications would be limited (you can't control the temperature well enough for small applications). It seems like if the density changes with temperature, an adjustable lens with no moving parts could be formed by creating an enclosure with a gas reservoir, and a convex portion containing the liquid and then simply changing the temperature would change the density and focus of the lens.
Or maybe I'm an idiot.
+Justin Hall Actually, liquid lenses are a real product. I'm not sure about using liquid CO2, but most liquid lenses use a combination of oil and water and a technique called electrowetting. I have a couple videos on the topic, just search for liquid lens.
Thanks, that was enlightening!
+Applied Science can you give for us the plan of construction for this chamber please?
actually I was thinking along the same lines. like using a phase change like that with a laser passed through and measure the wavelength change as the phases change.
I can make a 3d model + DWGs within one week for 10$.
Very interesting display of super critical fluid dynamics. Thank you for sharing your projects with us.
Nice project! Perhaps you can cool the aluminum with dry ice while mounting the bolts to avoid to much pressure being build before closing. If you manage to do this and you can heat it up even more than you do now. What kind of pressure are you able to reach?
You should have aluminum rings on the outsides of the plastic windows to support them all around at these pressures!
sorry for the noobs question.but isn't the whole (heated) thing just all gaseous?
How do you figuret it's supercritical?
thanks
Pressure. That's why he has the pressure gauge on top. We know by temperature and pressure what phase things will be at. Many common substances, especially CO2, are well documented.
Yves Baggi The gas and the liquid are at the same (or very close to the same) density. Just as a helium balloon floats in air, the liquid floats in the gas and they mix and become essentially the same thing.
That's not the right answer, because anything that you can read in a book should be measurable directly through an experiment (It is 35-36 Degrees C for CO2 I Believe).
This is the answer: If you look at a P-T phase diagram the Critical point is basically where there is no distinction between Gas and Liquid, it is both. As in the structure of the arranged molecules are the same. To show that it is the critical point you can perform tiny changes in the environment around the point to reduce your uncertainty and show that it is the Critical Point i.e. T+ΔT, P=Const, then P + ΔP, T+ΔT, then P-ΔP, T = Const, then finally P=Const, T-ΔT.
Keep doing that with smaller and smaller ΔT, ΔP and while ensuring the Mass / Volume are still const, to narrow down the exact the Super Critical point.
Cool video. Cody from Cody's lab sent me here. Now you have a new subscriber. Thanks Cody.
I enjoyed this immensely! Thanks Ben!
have you considered repeating this adding a quantity of water & algae to it to see if the algae wood survive & metabolize the carbon dioxide into a significant amount of oxygen ?
plants need oxygen too...
Akkupack thatis true but there still is some oxigen in the chamber to start with, you fill the chamber with water dryice and the remaining space is filled with air. After the alges start growing they will produce more oxigen then they consume with simple fotosynthetis: 6 CO2 + 6 H2O -> C6H12O6 + 6 O2
My guess is the CO2 would act as a solvent that would kill algae.
@@kreynolds1123 100% correct. The CO2 would dry the algae out within seconds, killing it rapidly.
Is this dry water now?
It appears to be confused and slightly moody water now . Very dry sense of humor though.
Dry ice literally means ice with no water content
@@justotalkalottashit8392 Read my comment again pls, ty
Fascinating Ben, thank you for sharing this.
Very informative, nice to see how it works inside, especially the state changes of the CO2, makes it easier to grasp whats going on in tyour closed vessel:). Lot of pressure, i hope that perspex is bloody thick!!
this is cool as all hell ! ....btw... from the simple way you filled it...theres prob just as much N & O2 in there as CO2 ....which surly effects the critical Lambda point/phase transition temps & pressures....& 2 valves would be ideal.....also I wonder how energetic the explosion would be if it failed ?
realcygnusHe spent a fair bit of time showing the deformation of the O-rings from escaping CO2 as he was torquing the bolts. That amount of CO2 should have been enough to purge any atmosphere out of the space.
thc extraction
Love it. I always wondered what that would look like.
Good question. As long as the CO2 is above the critical temperature and pressure, it is by definition a supercritical fluid.This implies that the chamber contain a certain amount of liquid before heating or else there will not be enough mass to raise the pressure high enough to reach criticality upon heating. If the chamber starts with only 5% liquid, no amount of heating will create a supercritical fluid. It needs to be *appx* 50% liquid to create enough pressure on heating to pass criticality.
How are you going to open it?
unscrew it
good luck what that
cool it down in dry ice so the pressure gets down. then open the screws
it‘ll most likely crack and blow up
Green coffee beans. That's not what we use CO2 extraction for in Canada. lol
STONEDay, OMG, you really SAID that? ROFLMAO
@@BruceNitroxpro Truth. Check out this video I shot of a commercial scale C02 extraction plant for cannabis [only]. ua-cam.com/video/oKkU2OnqAN0/v-deo.html
Appreciate the explanation technique.
Just SUPERB.
I stumbled across this video by accident. It is really cool, thanks for showing it!
Молодец! Нам нравятся твои видео! Продолжай в том же духе, дорогой друг 8))
Anyone else here from Cody's video on Supercritical CO2 in a Glass Tube? :D
no but i
No. I came from Periodic Table of Videos channel.
nope, never watched, i watch legit science
Cody is pretty "legit" lol. What is "non-legit" science anyway?
Lol, fair enough. I dont think cody is a scientologist though XD.
Excellent experiment! ... Possible solution to the rapid pressure increase during closure is mount the chamber into an arbor press with a corresponding plate fitted to it. Rack the press down quickly to limit the "O" ring creep? I expect that you would have thought of many similar solutions? ...... I like this type of work, ..... always interesting. .....
As a diver it would be interesting to show a demonstration on the non linear compressibility of air especially 200 Bar vs 300+, be a nice demo of why most opt for 230Bar 15L tanks vs 300Bar 12L tanks
Your electricity bill must be outrageous...
This thing looks so dangerous!
+Stingray my buddies tried to make a supercritical co2 extractor for plant oils... it exploded and blew a hole though a cinderblock wall
+rust blade Haha wow. Also, plant oils huh? Sounds fun!
Danger is 10% material, 90% moron.
@@rustblade5021 Pressure vessels in general can be so dangerous, but with supercritical fluids the danger is magnified because of the way it reacts to most types of seals and soft components. If your buddies try it in future, my advice is to use already tested and rated pressure vessels (such as industrial pressure cookers, they can be easily sourced cheaply), get the pipework welded where possible using pipes rated to a safety factor of 2 for the pressure they're aiming for), and if they must use seals, make sure they're made of Nylon or similar polymer material with a decent thickness flange on the connections. I've helped design a supercritical CO2 research rig, and the flanges we used were nearly two inches thick. I would also make sure they test it first using air so they know it's capable, air isn't quite so bad if the thing decides it's had enough. During testing, we deliberately attempted to cross the critical point using an expansion valve (it was a closed loop waste heat recovery system, a bit like a Brayton cycle), and I can't go into details, but lets just say some very scary things happened when crossing the critical point. I can see why most engineers tend to avoid it at all costs!
@@jonathanreynolds7886 Absolutely spot on!
To get the maximum dry ice in there, can you use a hole saw and cut a round shape? It may take some playing around with, but if the load is shaped ahead of time you could get a lot more inside. Also, perhaps a jig is required to hold the lid down while you fasten the bolts.
I like the science and your safety. Very cool. Im trying to make a simple vacuum chamber myself and am having difficulty in figuring out how thick of a sheet of polycarbonate to use on a 5 gal. Steel pot.
Who came here from Nile give a like xD
Hash oil!
+scowell underrated comment.
I regret to see this video so late. Love your work
It's also used for extracting essences and perfume compounds from plants.
Hi, very cool video and experiment! I don't know how I could miss it for so many years! Anyway, I have a question about the experiment that nobody has been able to answer so far: What if you filled up the whole chamber with liquid CO2 without leaving a bubble of gas phase in there at room temperature. Then heat it up. Will it still change to a homogenious gas phase? This would mean the CO2 molecules would be still as close to each other as they have been in the liquid phase, but now forming a gas phase with the same density, but different optical properties. Would that happen?
You can screw out pressure gauge to make it leak pressure while your ohring is crushing. Then you can screw gauge to stop leaking.
Very nice work anyway! It looks so nice and simple, i want to make the same one! ) Thanks for this video!
I want this as a desk ointment, it will freak the heck out of anyone whom pops in and asks stupid questions 😁
Great video 👍👍👍👍👍
I'd like to see a video of the phase changing with polarizing filters to see the stress on the acrylic
Excellent demonstration, thanks.
Nice, Ben. Thanks for posting. You might follow up with another video showing how the o-rings swell up like donuts after becoming "carbonated" over the course of 24-hrs under very high pressure. I know those on paintball tanks (especially the BUNA variety) become totally saturated with CO₂ in that amount of time. The o-rings are extremely fragile in their bloated state. Consumers generally don't know that CO₂ will migrate straight through an unopened Coca Cola PET soda bottle wall - sitting right there on the supermarket shelf at much lower pressures. Touch base with me and let me know how I might persuade you to slap another one of your gizmos together. Being able to see inside the pressure vessel - that's the ticket.
Thanks ! That was fantastic experiment !
thank you very much for such a great explanation...
Fascinating, well done. I assume the temperature was measured in °C? If so, do you think one could build a smaller version that gets heated by holding it in your hands? That would be a cool fidget., safety concerns aside.
Great job, appreciate your efforts.
Water vs Dry Ice: its because water has a much larger heat capacity and can therefore absorb a greater amount of energy per unit of mass of water vs co2. Loved the video by the way!
i recommend you build a similar vessel and use co2 for hot isostatic pressing, or HIP. You can grind up aluminum for example to a fine powered then mix with suitable wax and make injection mold to make the piece. then put it in the chamber and heat it and result will be hip part that has 100% theoretical density, higher than can be obtained from forging.
Like your meter, BK test bench 390, have one that unfortunately does not works anymore due to what I believe is a voltage regulator that went bad but can not find a replacement part. You are a great teacher, thanks for the video.
commendable safety precautions!
Suggestion: Make a steam engine that operates with a super critical medium! Great content as always, thanks!
This looks like Magic! Excellent.