How to make Ethane Refrigerant (R170)
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Published 2024-02-07
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In this video I'll show how to make Ethane gas (C2H6), also known as refrigerant R170. This is the slightly heavier cousin of Ethylene or "Ethene" which is C2H4 (Refrigerant R1150). Ethane has a boiling point of -88C compared to Ethylene's -104C.
The main motivation behind synthesizing Ethane was to have a refrigerant for the second stage of a cascade vapor compression system that could still reach ultra-low temperatures, but without as high of a pressure demand. Assuming a heat exchanger temperature of -20C on the first stage of a cascade system, it would take 25.3 bar or 352 psi to condense Ethylene, whereas Ethane would only require 14.2 bar or 191 psi. This means that a small system using the relatively weak reciprocating compressors from a mini-fridge or tabletop ice-maker could use Ethane for a second stage, whereas Ethylene would typically require a rotary compressor to handle the higher pressure.
Industrially, Ethane is produced from crude oil or by hydrogenation of Ethylene. The hydrogenation reaction occurs by passing Ethane and Hydrogen over a high temperature nickel catalyst. In theory this process could be done by an amateur/hobbyist, but there's actually a simpler method - electrolysis.
When an acetate solution undergoes electrolysis with a platinum anode (whether acetic acid, or some acetate salt), the acetate ions break up into Carbon Dioxide (CO2) and Ethane (C2H6), in a process known as Kolbe electrolysis. This is actually a pretty complicated process that involves a lot of organic chemistry that I don't understand - but it works.
In this video, I'll use Sodium Acetate as my electrolyte. Theoretically, straight Acetic Acid (or vinegar) can be used, but its electrical conductivity is extremely low, so Sodium Acetate is a better option. Over time, as the acetate ions are consumed, the Sodium Acetate becomes Sodium Carbonate, causing the solution to become basic (pH over 7.0). Once this happens, the Kolbe electrolysis process stops, and regular alkaline water electrolysis occurs, producing oxygen gas at the anode.
For this reason, the electrolyte needs to be made with a generous excess of acetic acid, and the reaction should be stopped if the cell pH goes above around 6-7. Since the gas output contains CO2, it has to be scrubbed with Calcium Hydroxide in order to extract the pure Ethane. I also included a dessicant canister in line with my scrubber, since the gas has a significant amount of moisture in it.
To demonstrate its refrigeration properties, I compressed my Ethane into a ~100cc pipe in an ice bath to force it to liquify, then discharged it through a valve. When the liquid Ethane is brought down to 1 atmosphere, it flashes to vapor and drops its temperature to -88C.
One additional advantage of Ethane over Ethylene is that it can be stored in liquid state at room temperature, since its critical point is 32C. At 25C, liquid Ethane has a pressure of 41.9 bar or 593 psi, so it could easily be stored in a tank meant for CO2 or Nitrous Oxide, which have much higher pressures in their liquid state at room temperature.
Link to Ethylene Synthesis video:
• Making Ethylene (Refrigerant R1150)
Music Used:
Kevin MacLeod - Bossa Antigua
Kevin MacLeod - Lobby Time
Kevin MacLeod - Groove Groove
Kevin MacLeod - George Street Shuffle
Kevin MacLeod - Hard Boiled
All Comments (21)
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I was informed that we're no longer living in the year 2002, so I've uploaded at 1080p instead of 720p, so the MS paint drawings will have more pixels now.
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Organic chemistry, stoichiometry, mechanical engineering, 3d printing, analog circuit design, and finally refrigerant testing. This video is a massive filter, you have to be one heck of a mega-geek to follow every bit of it. Amazing work!
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the 'accidently drank some' is somewhat concerning lol
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Yesss. Crazy fridge man is back
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Please, never stop making these videos. I’ve been following all the YouTube STEM channels for 10+ years and this is peak multi-discipline engineering and design. 3d printing Organic chemistry Cascade Refrigeration systems Refrigerant synthesis Raw Electronics PCB design Glass forming I couldn’t stop smiling with joy throughout the video due to the depth and overall production quality and excellent humour throughout.
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It might sound pretty weird but im pretty sure the oily layer you got is acetic acid. Because you have so much salts dissolved in the water (the sodium acetate) it causes the solubility of acetic acid to decrease to a point that it actually separates from the solution cus of the Ionic strength of the salts (fancy physico-chemistry crap). This effect is called the Salting Out effect, I have done that to separate ethanol from water so this could totally happen with acetic acid as well. As you noted later on, the layer disappeared after a couple of days cus, as you explained, the solution becomes more basic causing the deprotonation of the acid and putting it into solution. Also before someone "uhm aktchualu"`s me, even thought acetic acid has a density of 1.05 g/mL, the water solution is still heavier cus it has a lot of salts dissolved which cause the density to drastically increase.
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the radioshack thing got me in the feels, when you could find stores for actual electrical components
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I’m a mechanical engineer. Every time I see your new video, I get exited❤
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To Bend a Glass Tube without Kinking the Glass you can First Fill the Tube with Fine Quartz Sand (not sharp). This will keep the form of the tube while allowing you to make the bend and then drain out the sand to finish.
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The reason your ph is around 5.5 is because you made a buffer solution which will be made when you have a weak acid and it's associated anion. If you want to more carefully adjust your ph use the Henderson-hasselvoc equation and look up a table of pka
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This dude did more than all of pop science channels combined and cant wait for part 3 on Thompson cooler!
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9:38 You made your own circuit, just to see if you could???? You, my good sir are a certified madlad
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We're all nerds here with interest in multiple disciplines of engineering and science and you're absolutely killing it. Ben from Applied Science is the closest comparison I can think of and I think most will agree he had a massive impact on the youtube engineering community. We love every minute of your videos, keep it up!
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Bro I am crying laughing at the shiba bonking the double bond, you are so fucking funny
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I usually watch YouTube videos sort of ambiently, in the background, while doing other things. If I DARE attempt to multitask for so much as TEN SECONDS while your vid is playing I get lost and have to rewind. Why would I admit this publicly? Well, as the admission reveals, I am, in fact, stupid.
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Dudes into Hydrocarbons he likes em Thicc like Ethane
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You could in theory bubble the gaz in some water saturated with sodium hydroxide : NaOH. The CO2 would react with the OH anions to produce at the end Na2CO3 which is basically sodium bicarbonate but stronger. At first your solution would be around 1kg/L of lye if you're around 20°C, CO2 would dissolve in the water to give H2CO3 which reacts with NaOH to give water and Na2CO3. The lye is consumed and the concentration sodium carbonate rises. You'll reach a point where it will be saturated. CO2 will dissolve and basically fall down as cristals at the bottom. You can use the sodium carbonate back on the sodium acetate to deprotonate it. Ideally you'd want to make this in cold water (near 0) because the CO2 is more soluble at that temperature where Na2CO3 is not so it will precipitate quicker. Lye is also two times less soluble in cold water but that's ok ig. Ah and ethane is not soluble in water. Like just no it would influence the yield in any way
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Did anyone else feel bad when he released all of his liquified Ethane that took 2 weeks to produce in all of 5 seconds?!? I was like duuude, close the valve close the valve!
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Great video of applied organic chemistry and electronics. I majored in chemistry for 3 years and then switched to electrical engineering graduating in 85 with a bsee, and yet without a lot of refreshing I could never do what you have done in this video simply because I never used any of what I learned in college. I love.watching your videos and your explanations are great.
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I built my own automated hydrogen generator using your design and it works amazingly. Thank you so much for your efforts!
