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Author Topic: Why does PURE OXYGEN need to be stored in a pressurized container?  (Read 2003 times)

Offline OXY Moron

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Why can't we just store it in a normal water bottle or glass jar or some other type of air tight container?

Or can we?


NB: for the sake of this discussion, by 'pure' I'm really talking about anything above 90% o2 content.



 

Offline evan_au

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We can store O2 in a normal glass or plastic bottle. At atmospheric pressure, you can put 1 litre of O2 in a 1 litre bottle.

If you are prepared to pressurize it a bit (like softdrink or sparkling mineral water), you might be able to put 1.2 litres of O2 in a 1 litre plastic bottle.

If you are prepared to pressurize it to a liquid, you could fit over 500 litres in a 1 litre (very strong) bottle.

A normal breath of air draws in about 100ml of oxygen. If you don't purify & recycle it:
  • A 1 litre plastic bottle of oxygen gas could hold 12 breaths
  • A 1 litre steel bottle of liquid oxygen could hold 5000 breaths (but is a lot less portable)
 
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Offline alancalverd

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To get more oxygen in a smaller space. You have to make various compromises about strength, weight, flammability and longevity of the bottle. Aluminium is good for aircraft, steel is better for use on a factory floor.
 
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Offline Bored chemist

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If you are prepared to pressurize it to a liquid,

I  might be prepared to do so, but at normal temperatures  I can't.
http://www.engineeringtoolbox.com/gas-critical-temperature-pressure-d_161.html
I could cooli it down and pressurise it then store it as a liquid.
Or I could cool it still further and store it as a liquid at normal atmospheric pressure.
 
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Offline OXY Moron

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A normal breath of air draws in about 100ml of oxygen. If you don't purify & recycle it:

Thanks evan_au!

Just to clarify, are you saying a normal breath of normal air (ie: with an o2 content around 20%), will draw in 100 ml of o2?

If so, would that mean that the same normal breath of 100% PURE o2 (that has 5x the o2 content of 'normal' air), would draw in 500 ml of o2?

 

Offline OXY Moron

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To get more oxygen in a smaller space

Thanks alancalverd!

I'm really more concerned about the purity of the o2 as opposed to volume.

As I understand it, the air we breathe has 20% o2 content. Medical Grade o2 is 99%.

Is is possible to store that Medical Grade o2 in water bottle/jar/etc or does it need to be pressurized?

 

Offline chiralSPO

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I don't recommend trying to breath pure O2. Medical-grade oxygen is very pure, but is usually diluted with another gas (like nitrogen or air). Too much oxygen can be poisonous, and there are other risks (such as fire) to having high concentrations of oxygen around.

As has been mentioned before, it is entirely possible to store oxygen at atmospheric pressure in a normal bottle or balloon or bag, but you would need a very large volume of oxygen for even a few minutes of breathing (if that is your goal).

What is your goal?
 
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Offline OXY Moron

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What is your goal?

Thanks chiralSPO!

I'm based in Asia and sick and tired of breathing crappy air!

Not necessarily looking for extended breathing duration, more so for a way to get few puffs/shots of fresh air every now and then.

I watched an American Football Game the other day and some guys on the bench were taking in some o2 when they came off after a play. Turning to the haze outside my window I started thinking, 'Wouldn't THAT be nice!'
 

Offline evan_au

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Quote from: OXY Moron
Just to clarify, are you saying a normal breath of normal air (ie: with an o2 content around 20%), will draw in 100 ml of o2?
While adult humans have a lung capacity of over 3 litres, an average breath is around 0.5l (500ml); this is called the tidal volume.

Air is around 20% oxygen, which means that an average 500ml breath will have about 100ml of oxygen and 400ml of nitrogen (with some smaller components like argon, water vapor and carbon dioxide).
 
 
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Offline chiralSPO

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What is your goal?

Thanks chiralSPO!

I'm based in Asia and sick and tired of breathing crappy air!

Not necessarily looking for extended breathing duration, more so for a way to get few puffs/shots of fresh air every now and then.

I watched an American Football Game the other day and some guys on the bench were taking in some o2 when they came off after a play. Turning to the haze outside my window I started thinking, 'Wouldn't THAT be nice!'

The air in Asia is "crappy" not because of a lack of oxygen, but because of pollutants--mostly particulate. I think investing in an air purifier will be much cheaper and more effective in the long run than trying to make (or buy) your own air.

You can buy an air purifier for your home for a couple hundred dollars (not cheap but not crazy, especially if it means getting a break from bad air!)

I also recommend trying to do something about the air quality where you live. I don't know where you are, or how your government works, but I bet there are already other citizens near you, who are trying to convince the government to regulate polluters. Go to a rally (or organize one), sign a petition (or start one), write a letter to an official, and vote (if you can) to try to change it.* Clean air is a right.

*If you live somewhere where this kind of political activism is illegal, this might not be a good idea...
 
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Offline wolfekeeper

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I agree that filtering is likely to be far, far more practical, but FWIW portable clean air is available commercially, it's called 'SCUBA'!!

Rebreather technologies can minimise the amount of oxygen you need; 80% of the inhaled oxygen is not consumed, so scrubbing out the CO2 and recirculating the air is far more lightweight.
 

Offline Bored chemist

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How much does a rebreather cartridge cost and how long does it last?
 

Offline RD

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There are medical devices which concentrate oxygen from the air ...
https://en.wikipedia.org/wiki/Oxygen_concentrator
not worth the money unless you have serious lung/heart disease.
 

Offline wolfekeeper

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How much does a rebreather cartridge cost and how long does it last?
googling and picking a manufacturer at random:

https://www.divegearexpress.com/sofnolime-797-44-lb-20-kg-keg-8-12-mesh

They claim 150 l of CO2 per kg of product and the product costs about 5/kg.

Not sure off-hand how many litres of CO2 the average person emits per hour, presumably the same as they actually metabolise, 20ml per breath, let's say 25 breaths per minute, that's 500ml oxygen per minute, 30 litres per hour. Pound an hour for the scrubber. Probably not worth it compared to liquid air.
 

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