Thermodynamics - Explaining the Critical Point

This experiment demonstrates the behavior of carbon dioxide around the critical point. It shows the transition of a liquid-vapour-mixture to the supercritical state and back. Watch how the phase boundary disappears and reappears. There is also a short description of the process in a P-T-diagram.
Created by mechanical engineering students and the Centre for New Meda at Bergen University College, Norway.
www.hib.no/en/

[@M_0892]

Finally I understand what it means when there is no distinction between gas and liquid phase. Thanks so much!

[@Jerry13Only]

They didn't specify this, but it becomes a supercritical fluid

[@bikramsaha1932]

me too... I can finally sleep well now

[@johnathanjesse8962]

dont know if you guys gives a damn but if you are bored like me atm you can watch pretty much all the latest series on instaflixxer. Have been streaming with my brother for the last months =)

[@allenkamdyn9113]

@Johnathan Jesse yup, been using InstaFlixxer for years myself :D

[@stethinsights]

I came here because of the same confusion...😅😊

[@Lexi-vj1lm]

i finally understand this concept! it was so hard to conceptualize without this visual and audio aid. thank you!! i wish i could swim in liquid gas.

[@MrKnutriis]

Yes, water.

[@samueladitya1729]

@@MrKnutriis in supercritical water!

[@taiken64]

@@samueladitya1729 374+ degrees Celsius and 22,089+ kPa does not sound like a fun time, even for an instant.

[@TheSunshineRequiem]

this is amazing, i am annoyed that professors always talk about those stuff like its nothing, they have seen it so many times of course its normal to them, but not to students.

[@sychomadman]

So trueeeee....

[@johnnyq4260]

I bet most of the profs have never seen it with their own eyes.

[@rkmcnair62]

Best visual example of superfluid transition I've seen on youtube.

[@edwardgrigoryan3982]

I agree. Watched a bunch and this one takes the cake.

[@billymcgregor2067]

but it's not a superfluid, it's just CO2

[@tilingsunshinecoast1934]

Your dedication to your audience is commendable.

[@luanalopes8430]

I'm a brazilian high school senior and I liked this video a lot! Thank you!

[@mungelomwaangasikateyo376]

I am now addicted to seeing supercritical fluids, thank you 😊

[@sudha4674]

you would make our kids to think next level in science. Keep release as many as possible.

[@myx0myc0t4]

Hi guys, I'm learning about electron microscopy where we use critical point drying for the samples. It's so very helpful to understand through your presentation what critical point means, and how it looks like. thank you.

[@shreeshailkanakal5612]

I couldn't imagine how would there not be any distinction between the liquid and gaseous state...this helped me a lot , this is what I wanted.thank you a lot😊😊.

[@sanjidaislamshova9642]

It's super amazing. I am a student of class 11. I couldn’t understand what does it mean by critical temperature. But now i have seen it with my eyes, i am speechless. It was so interesting to see the form of super critical gas where there is no distinction between liquid and gas phase. Thank you so much for this video😊

[@A.ll_myself_]

Super heated fluid 🤩

[@mateomartinez9056]

This is one of the most beautiful videos ive ever had the pleasure to find. Thank you so much for taking the time to produce such an excellent experiment

[@ka6091]

thanks for the demonstration, it makes everything so much easier to understand

[@ammar.a2950]

First time I've seen a super critical liquid! I need to see mooore :D

[@hellovikramjeet]

This is the coolest thing I saw and is absolutely wonderful! I had NNNOOOOO idea what it meant or how it looked when the Liq/Vap boundary vanishes. Thanks very much

[@nothingisreal6816]

That's what I call good production quality. GJ

[@jjortiz7504]

This demonstration made me go "oooooohhhh" when i realized what "liquid and vapor distinction" meant. Thank you very much.

[@bayram6561]

glad you've discovered or are enjoying this

[@olafderhobbit6791]

Very nice explanation and visualization of the supercritical state. I finally understood. Thanks a lot!

[@janefokr3309]

This is sooo cool!! Amazing work guys!

[@manojkumars1931]

it was a very good video understood the triple point and critical point clearly, thank you for the team making this video with all your efforts.

[@tanyasinha8766]

This is exactly what I was looking for. Many thanks! The video was really clear.

[@mvmcali6900]

Best explanation ever of super critical

[@haribo1319]

Amazing video, thank you so much for explaining/demonstrating critical point in such an effective way!

[@HerumbSahay]

these concepts are cool in theory and all but nothing beats the moment you see these changes happening with your own eyes

[@suheladesilva2933]

Great video, thanks for the practical demonstration, really appreciate your effort.

[@m.caeben2578]

You mean my caffeine comes god like reality warping tech where liquid and gas have no meaning? The video was really interesting. Thanks for doing it.

[@omsingharjit]

3:35 if it's not solid , liquid , or gas then what really is it ? I mean seeing it seems liquid turned into gas which became invisible ! But why it's not the case . And why it's usually said there's 3 States of mater instead of 4 where 4th should be supercritical ? ( Ignore plasma state for simplicity )

[@Ydidutakemyname]

technically it's just a fluid as both gases and liquids are fluids

[@TheReaLucyFord]

Perfect Explanation! Very helpful thank you so much!

[@saikrishnadittakavi6269]

Simply fantabulous! Thanks.

[@ikatara.iktara]

thanks brother for explaining this concept experimentaly

[@maxrocks00]

but is there still both liquid and gas inside of it? or is it like a different state of matter?

[@zitrone5155]

nearly all of us came from the sentence that says no distinction between liquid and gas from cengel's thermo book

[@chriswyatt66]

Excellent explaination !

[@ye3068]

Sehr gut erklärt, danke euch!

[@tmead07]

Thanks for the video! You explained it very well. I was reading about the planet Jupiter and learned that most of it is in a supercritical state, but didn't know what that meant.

[@glasslinesmadhes]

Well explained demo. Love it fantastic way.

[@JDT738126]

Awesome video! Thanks for sharing!

[@optimusdererste3148]

There is one major mistake in your video: The phase diagram you are showing is the one for an anomalous fluid like water and not for normal fluids like CO2. Anyway, good video!

[@MrNabows]

doesn't matter, cause the annomaly is usually between solid and liquid phase.

[@Hambxne]

whats the difference between an anomalous fluid and normal fluid?

[@MrNabows]

@@Hambxne depends on the definition. On this specific case, it means that the molar volume of ice is bigger than water. Usually, in a solid phase the molecules are more tightly bound, therefore, the molar volume is usually smaller for the solid phase, on water, it's the opposite, that's why ice floats on water!

[@Hambxne]

@@MrNabows ahhh okay so its just a fancy way to talk about density after phase changes, awesome! thank you for the concise breakdown!

[@leax1666]

Mr. N. Anyway the graphic is incorrect , if he is showing critical phase, it has to show has , the graf of a critical CO2 , not from water , big mistake

[@abdelrahmanmohamed5768]

How is the pressure increased here? by incresing temperature only?

[@DerkyYog]

This was great, thank you very much!

[@umedina98]

Amazing video!

[@mysterywoman8158]

Very helpful. Thank you.

[@preetibhall]

hey can u pls tell what actually happened AT CRITICAL POINT ?

[@mysterywoman8158]

So at first we had a clear separation between the liquid and vapour. Then when the temp and pressure is raised to the critical point, the boundary between the 2 phases disappear. So, at the critical point the liquid and vapour have the same density and that’s why we can’t distinguish between the vapour and the liquid.

[@preetibhall]

@@mysterywoman8158 thnkuuu

[@mysterywoman8158]

@@preetibhall its okay

[@abhishekkardam8750]

Thanks I understand the critical point.😎🔥

[@realitykicksin8755]

This is my favourite video!

[@steveboel12]

How come some phase diagrams have the line that "divides" solid and liquid, in the "up and to the right" direction, but some have it "up and to the left?"

[@발__젭]

유익해요

[@kingbaalzebb]

저도 그렇게 생각해요 발젭님

[@PareshGujarati]

Very good explanation. Thank you

[@raunakkbanerjee9016]

Nice Demonstration

[@dibyangshukashyap5412]

Thank you sir!

[@stevesilverman3505]

What would happen if supercritial CO2 was suddenly reduced to atmospheric pressure by an opening in the container? Would it return to a liquid and boil or would it return to dry ice?

[@rajdeepsrivastava3035]

it will probably boil away

[@felixsanchez2143]

Very nice explanation!

[@johno9507]

Fascinating, thanks.

[@blaine4754]

Blew my mind.

[@rashidulbari1115]

Jesus!! Amazing!!

[@Snoozybro]

Wow..! This is great..

[@ahmad.s94]

Thank you so much

[@andreyandrey9197]

I wonder what kind of transparent material is this? What is it called?

[@rgorbunov]

beautiful! Ty

[@nityadas6846]

Can you please share the name of the materials of the different parts of this beautiful device ?

[@NehaSharma-od5gz]

So what did exactly happen in the chamber? The liquid and vapour phase became one? The CO2 was both in liquid and vapour phase at same time? I'm still a bit confused..

[@hsaqer007]

شكراً على المحتوى الرائع 🌹

[@zakariaaouchette5702]

Ein wnderschönes Phänomen, Vielen Dank sehr.

[@abdullahkatr8115]

Perfect! Thanks, guys

[@adirmugrabi]

is there any material that is super critical in human conditions?

[@bobbysama6282]

Amazing!! thank you so much

[@blockparty5695]

Is that the unit Ben made?

[@ThatBoiAbdu]

Great explanation. Thank you.

[@ouvertn]

very very helpful. Thank you so much

[@jairherrera7144]

I have two doubts, what the person does when he unscrews the metal part in the minute 2:22, and the second doubt is that there is root to watch this video investigate and there is a Gay-Lussac law that says that the pressure is directly proportional to the temperature and the minute 2:44, when the temperature rises the pressure also increases but when the temperature decreases the pressure does not drop.

[@sukruthas1646]

Wow wow wow ❤❤💃. Thanks a lot sir 👏👏👏

[@janekim1784]

How did you make the chamber? is there some papers related to make chamber processing?

[@santiagosanchezsarfati7460]

I would like the answer

[@SuperSuori]

What happens when you fill it with way more CO2 liquid, or barely any CO2?

[@medielabhvl366]

As it’s shown in the film, it took some trial and error to get the amount of dry ice right in order to get a useful liquid-vapour-mixture to start with. Too little dry ice may result in a pure gas phase already at room temperature and then it turned out to be difficult to observe a phase boundary between liquid and gas phase on the way to the supercritical state. On the other hand, too much dry ice could result in a too quick pressure rise already when the CO2 in the pressure chamber goes to its initial equilibrium state (before the heating plate is turned on). Therefore, it is important to have an automatic pressure relief valve, which opens at a predefined pressure, as one of several safety measures when conducting experiments like this.

[@AdityaKumar-ij5ok]

Medielab HVL does it need to be trial and error? the remaining critical constant not so much talked about is critical volume (molar volume at T_cr and P_cr), I think if we knew the volume of cylinder and and a relation between volume of solid CO2 and supercritical fluid CO2 for a particular number of moles, then it will be predetermined what amount of dry ice will go into the cylinder. i am just a high school kid, btw, does the remaining volume of cylinder at the start(just after putting dry ice), that's get filled with air, affect the state?

[@dmelorj]

Thank you!

[@turbo2ltr]

When you are cooling the chamber, there appears to be 2 phase transitions that come together in the middle. Is that liquid on the bottom, gas on on top and super critical in the middle?

[@shadow_jacker]

I believe supercritical is the mixture of gaseous and liquid state. That is the phase boundary where both the states are in physical equilibrium

[@souparnadhar7034]

This is what youtube is meant for.... 😍

[@enderredacted112]

*A scientist with laovaan's voice.*

[@STIZEN9]

is the viewing glass made of quartz?

[@medielabhvl366]

It is acryl glass with a thickness of 30 mm. They have to be replaced regularly because the material becomes opaque after several runs of the experiment. You also have to be careful when drilling the holes for the bolts. Acryl is a bit brittle and higher drilling speeds may lead to some cracking of the material.

[@santiagosanchezsarfati7460]

Is there any way to buy the vessel? I mean for educational purposes in such a small scale...

[@zenithvirgina655]

Is there a journal?

[@animal_shorts1]

thanks

[@loscarsonproductions6578]

Hello, first of all your video is amazing. Right now I am designing a pressure vessel for polymer foaming process so I want to know if you have a document where the instructions and materials are presented. Any advice will be appreciated also. Thanks.

[@shinronin7312]

finally some quality video explaining shit. thanks

[@lv__up551]

Thanks. I should be studying for my exams but now I´m going to find out how to remove coffeine from coffee beans with supercritical CO2 ...

[@AliAhmed-fi1oj]

Hi, what is the brand name of the system that you are using ?

[@tanishjambhekar7642]

afriso

[@monicanagaraj1828]

keep it up!!! great gob!!

[@ralghahhallas2460]

Nice demo. Could you guys provide me a link to a good paper on SCF CO2 thermodynamics. I'm working on a project that utilizes SCF CO2 for a geothermal thermosyphon application. I'm am particularity interested in mass and heat transfer in between the liquid and SCF "vapor" phases in equilibrium both in the nucleation and condensation processes.

[@jokermau]

Evil application, that of removing caffeine from coffee beans! Apart of that, adorable demonstration!

[@Barinderkhalsa]

Very nice

[@kaptaan_97]

what if we open the system suddenly at the supercritical condition to the atmosphere?

[@onetrickhorse]

The pressure would rapidly drop, and as a result, the temperature too, causing initially a violent jet of CO2 out of the vessel as it expands, then rapidly forming liquid CO2 droplets and vapour (depending on the room temperature, size of the CO2 chamber, and size of the opening) as it cooled rapidly. It would almost certainly condense moisture in the air rapidly too. The vapour/liquid could also rapidly solidify into dry ice crystals , since the expansion from 70+ bar to 1 bar would likely result in lower than ambient temperatures in the CO2. It would instantly fall below the critical pressure and temperature.

[@theweirdwolf1877]

@@onetrickhorsewould it cause a drop in temperature? The highly pressurised gas being released into 1 atm will just expand very quickly out into the surroundings but should stay at the same temperature, and it would just turn into co2 vapour

[@onetrickhorse]

@@theweirdwolf1877 indeed, so the release of the CO2 from high pressure to low pressure undergoes expansion that relates to Boyle's law, which states that P1*V1 = P2*V2, in other words, as the pressure drops from P1 to P2, the volume increases proportionally. Because the thermal energy in a fixed volume V1 is the same as the thermal energy in the volume V2, the thermal energy is spread over a larger volume, which results in the drop in temperature though expansion for that new volume.

[@lombizrak2480]

Schönes Video und ein netter deutscher Akzent. 😁

[@Liguehunters]

Looks very similar to the thing applied Science build

[@mjylove2]

very nice. very very nice

[@boostav]

Why does the amount of liquid CO2 increase as the temperature goes up? I would have thought it would decrease.

[@mdaamirsohail1492]

Its because of expansion of liquid, when you heat a liquid it will expand that is why you can see its level rising up with increase in temperature.

[@musicistheway7463]

wow. just wow.

[@csabafulop9224]

where to buy from this vessel?

[@charly9767]

What are you adjusting on second 2:22?

[@ns1001]

Probably closing the bleeding valve

[@엥-u3h]

Kim Joon bring me here

[@Viewtifuljupitah]

very informative and believe if you were to present your research more enthusiastically it would be much easier to receive

[@ธิดารัตน์คชาธาร-ม7ญ]

I want to do this piece of work. And how to do it.

[@QanatGiniat]

Wow! Good job! / Myqty jigitter!