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Its like Liquid Nitrogen – but Fire!

September 29, 2019


Hey guys backyard scientist here, today I’m going to be doing some interesting demonstrations and experiments with methane gas, and there’s a couple of interesting things about it. Number one: it’s just like helium, it’s lighter than air- -except fire! And as a liquid, liquid methane behaves just like liquid nitrogen. Whoa-ohh! Except it’s flammable Whoa! Look at that bounce around like that. So that was pretty cool, or hot, I don’t even know with this video anymore. I’m all confused at this point, but basically, methane is a gas. So how do we turn into a liquid like the liquid nitrogen? Well, what we have to do is fill up a big balloon full of methane gas from the bottle, and then submerge it into liquid nitrogen. What will happen is: The methane gas will condense on the inside of this test tube. Like, if you leave a cool drink out on a hot summer day, and the water vapor condenses on the outside of the glass- -that’s what’s going to happen on the inside of this test tube. We’ve got a balloon full of gas, so now we need to fill this up with liquid nitrogen! (whoosh) I’m pretty surprised if this is glass isn’t breaking, but now we’ll put the test tube in here and we’ll watch and see what happens. It’s really funny to think about how liquid nitrogen is boiling, but it’s actually boiling, and it’s so cold it can freeze stuff. Like, liquid methane. Anyway, the process doesn’t take very long at all. I mean it takes like five minutes per balloon. That’s not long at all, and it’s a really easy way to do it. Well, it looks like the five minutes are up, let’s try our first experiment. Aha, here it is. This is our first test of the liquid methane! You can see it’s bubbling in there, and smoking, so I’m going to do a cool test, a cool demonstration! I’m gonna get up on that ladder, light it on fire, and pour it on the floor. I think something cool should happen. Let’s try it Sandra: Hopefully nothing too cool to my toes. Okay, here we go three two one. (whoosh) Holy, whoOOOAAAAAAA! That was awesome! Look, they’re still going! Sandra: That was SUPER cool!!! Did you see that? That was hot! I think we have to try that again. Alright, are you ready? Sandra: Kinda. Three, two, one, (whoosh) Sandra: woooooo! (sizzling) Sandra: That was super, that was the best one by far. That was perfect. Woah!! We were having a lot of fun with this, and we wanted to try some new things to get some cool camera angles of it So we put this slow-motion camera on a skateboard, and pulled it back as soon as I did the methane on the ground. I think that it turned out pretty cool. So the reason this works with methane, liquid methane and not other liquid gases like liquid propane or liquid butane, is because of the Leidenfrost effect. Basically, from the liquid methane’s perspective the floor is literally lava. It can’t even get close enough to touch it before it starts boiling away. That’s why there’s no physical contact, it’s just floating on a barrier of its own vapor. Okay, in this hand I have a test tube of liquid nitrogen that’s getting very cold very fast, and in this hand I have a test tube full of methane. We know methane is very flammable, and we know that liquid nitrogen smothers fires, like from that video I did with fire in my pool. So, what happens if I mix them together? Let’s find out! Do they even mix? So there’s the methane- -there’s the nitrogen, all in one big happy family. So, now, let’s set it on fire and see what happens. Ah, look at that! Nothing happens. Interesting, let’s zoom in. Aha, it started on fire now! That was pretty interesting, at first I guess there was enough liquid nitrogen boiling away nitrogen gas to keep the fire smothered, so it couldn’t reach oxygen, and it couldn’t catch on fire, and then the excess liquid nitrogen boiled away leaving enough methane to sustain its own combustion. I tried this again by adding some liquid methane to the dish, and then lighting it on fire, and then I got some liquid nitrogen to pour it on the fire, and look at that, the fire just went right out. And after a couple of seconds of the liquid nitrogen boiling away, I could light the methane back on fire again again. So we’ve been doing a lot of stuff with methane, but we never stopped to ask: What is methane, or, how is methane? Nobody ever asks that… Anyway, methane is a simple hydrocarbon! It’s the lightest carbon there is, and it normally comes from: natural gas reserves, cows, bacterial decay, and other stuff like that. So what are some uses of methane, besides well, just burning and setting it on fire for fun? Well, it’s used as a rocket fuel. It’s used as a fuel for keeping your house warm, and keeping your water warm, and some other boring stuff like hydrogen and ammonia synthesis, but who cares about that, but what it’s really good at is setting stuff on fire. So here’s some more fun methane facts for ya: I’ve been wanting to do this video for a while, but I couldn’t find any methane. The only methane that I could find was a two hundred dollar bottle of chemically pure methane that’s a funny story because I came home and realized I have a natural gas line attached to my house, which is basically almost pure methane. So, rip! Anyway, how much do they overpay for that methane? Let’s say this balloon is 18 inches in diameter. That means it contains 1.7 cubic feet of methane. So that means the cost per balloon that I fill up is basically four and a half dollars per balloon. The natural gas that comes from my utility is billed per 100 cubic feet and for 100 cubic feet of natural gas: I would only pay 32 cents. So the cost per balloon from my natural gas company: half of one penny. And I ended up paying four dollars and 50 cents per balloon! Ahhhh!!!! Anyway, I just thought you guys would find that interesting. Moving on to the next experiment. Next, I wanted to try this I saw the Mythbusters do this a long time ago and they ended the episode like this: Mythbusters: This one… it’s not safe pretty much for any of our viewers. We’ve done it. Now you don’t have to. Challenge accepted. So remember when I said that methane is lighter than air? Well something cool you can do with that is put a bunch of methane into a container full of soapy water to make these bubbles that are lighter than air and also: flammable! Woah!!! That was a big one.
Sandra: That was bright! Yea it was! Now I’m just gonna let this go and see how tall of a bubble tower I can get it. Grow my bubbles! Grow!!! All right. This one’s getting pretty tall. Should I do it do it? Sandra: Do it! (in awe) Woahhh!!!! Oh my- I gotta put this out, hold on. Whoa, did you see that? That was like a 20-foot tall pillar of flame. Sandra: That was way cooler than I anticipated Sandra: Oh! Right in your hand! Sandra: Did it hurt? No, not at all. Sandra: Left some residue. Oh, that’s just burnt skin. (laughter) All right, let’s send a couple more up into the air, then we got one more experiment planned. These bubbles are fun to play with and it’s fun to try to figure out other stuff to do with them and I had all these leftover fireworks from 4th of July so I figured out: hey, why not, let’s test my accuracy. (music) Bye bye! Just kidding! Ha haaaa! (laughter) (laughter) Sandra: Oh, that was cool! ♪ I like big bubbles and I cannot lie! ♪ So, another interesting thing I thought I would mention is the pressure of my natural gas line is very low by itself. You can only get like a couple bubbles if you put it in the water, but if you use this, this is a fridge compressor, and this is sucking extra natural gas into here and pumping it out, so I get a higher volume of gas going into there so I can make more bubbles faster, right? Should I send it? Sandra: Send it! Hoahh!! Beautiful! Here we go! Sandra: Ooh now you can really tell how big the fireball is. (agreeing) Yeah. Alright, guide it, and- Oo! All right, so now we’re going to try it, (balloon deflating) (laughter) Sandra: Release a little methane. Literally! Now we’re gonna try it in the pool and see what happens. Should I just pour it in, or- -try to throw it? Or I’ll just like pour it in right here, see what happens. All right, here we go. Sandra: Light it good. Sandra: Let it sit for a minute. Get nice and hot? Sandra: Yeah, nice and hot. Sandra: Okay. Okay, that might be- that might be too good. Oh, gonna burn the plants! So yeah, let’s see what happens. Ahhhhhh! That pillar of fire! And look at that, look at it scoot across the water like that! Let’s see if I can pick one up or combine them. (together, in awe) Woahh!!!! Now it’s hot! Here we go now watch this! (Sandra impressed) Ooooo! It’s gone, it’s magic! What about this one? Does get hot after a while! You see that? Sandra: Oh, cool! So anyway, before we go, I have a PSA for you viewers that are also in Florida like me. This is a giant air plant. And right now they’re actually endangered, they’re very endangered, almost 90% of them have been lost to what’s known as: The Mexican bromeliad weevil. It’s an illegal immigrant from Mexico that’s come on in and starting to destroy these air plants. This is a very interesting plant, because it lives for about 20 years, it gets really big for an air plant. It sends up this big flowering spike at the end of its lifespan. It flowers and releases up thousands of little floaty seeds that float through the air, and then it dies. That’s it. It’s over for this plant. So, you know, they don’t- -that’s the only way they reproduce, it’s hard to find them nowadays in the wild, so if you see one that’s falling into your yard after a storm, take care of it, put it in a tree, do something nice with it, and take care of it, because you would be helping out. So that’s it for this video guys, I’ll put some more information about the air plant down below, and see you guys next time. Thanks for watching. Bye! (music)

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