Sciencemadness Discussion Board

liquifying SO2 into a disoposable helium tank

6dthjd1 - 14-11-2022 at 23:20

I've read the sulfur dioxide and Ammonia both liquify relatively easily compared to other common gases.


Sulfur dioxide is said to be not very aggressive to steel when dry.

The tank once held 14.9 cubic feet of helium.

So I was wondering if I could fill it with roughly 900 grams of sulfur dioxide?

https://fire.lacounty.gov/wp-content/uploads/2019/08/Gas_Con...

Tsjerk - 15-11-2022 at 01:47

900 grams wouldn't fill a 420 liter cylinder would it? If you would pull a complete vacuum on the tank and fill it with 14 moles of SO2 you would still have a vacuum in the tank.

6dthjd1 - 15-11-2022 at 05:17

Quote: Originally posted by Tsjerk  
900 grams wouldn't fill a 420 liter cylinder would it? If you would pull a complete vacuum on the tank and fill it with 14 moles of SO2 you would still have a vacuum in the tank.


I think the tank has residual air. the helium was only 80%.

Given that this is disposable I would rather not fill it to the max (80% of capacity for safety reasons)

Tsjerk - 15-11-2022 at 05:24

Quote: Originally posted by 6dthjd1  

I think the tank has residual air. the helium was only 80%.

Given that this is disposable I would rather not fill it to the max (80% of capacity for safety reasons)


Then how will you get the gas out?

6dthjd1 - 15-11-2022 at 12:42

Quote: Originally posted by Tsjerk  
Quote: Originally posted by 6dthjd1  

I think the tank has residual air. the helium was only 80%.

Given that this is disposable I would rather not fill it to the max (80% of capacity for safety reasons)


Then how will you get the gas out?


Well I just learned the tank is still filled It gives a rushing sound when the black nozzle is bent.

So I guess I have no cylinder to use.

Texium - 15-11-2022 at 13:16

Quote: Originally posted by Tsjerk  
900 grams wouldn't fill a 420 liter cylinder would it? If you would pull a complete vacuum on the tank and fill it with 14 moles of SO2 you would still have a vacuum in the tank.
The cylinder is much smaller. The cubic feet figure is based on uncompressed volume. The liquid volume would only be about 560 mL, based on the chart that OP linked. Given that, the 900 g of SO2 isn't far off. I calculated about 800 grams myself.

So in theory, yes, it's possible. However, it's very poor and unsafe practice to refill a cylinder that is not intended to be refilled, especially with a different gas than what it was designed for. Especially with a gas that is potentially corrosive. In order to accomplish this, you'd need to generate clean SO2, get it bone dry somehow, and then cool it in your cylinder to below -10ºC without allowing any water vapor to condense with it, before sealing the cylinder. Not an easy task whatsoever, and it's still a bad idea from a safety perspective even if you did everything right.