Oxygen in bottles

[obbn]

Hello Everyone,
I am just wondering how they produce oxygen that they put into bottles for medical use. I wouldn’t think that it was just plain air, compressed into the bottle. I am assuming it is pure oxygen and my thought is that it is made from water. IE: the separation of hydrogen and the oxygen molecules. But I really have no idea.

[running_coach]

My wife is on home oxygen. This is how it works. The same machine is also used to fill bottles for use outside the house.

It has two cylinders filled with zeolite which selectively adsorbs the nitrogen in the air. In each cycle, air flows through one cylinder at a pressure of around 20 psig, where psig indicates the gauge pressure (138 kPa, or 1.36 atmospheres) where the nitrogen molecules are captured by the zeolite, while the other cylinder is vented off to ambient atmospheric pressure allowing the captured nitrogen to dissipate.

I don’t know if the same system is used commercially.

[hibernicus]

Oxygen is produced by fractional distillation of air. If you cool the air to a temperature below the boiling point of oxygen, but above the boiling point of nitrogen, you can separate the liquid oxygen from the gaseous nitrogen, and bottle both separately for sale.

[Napier]

I don’t think any of these is right. I am sure they don’t electrolyze water, because for one thing that takes a great deal of energy to get the oxygen, whereas there is about three pounds of oxygen already resting on every single square foot of the earth’s surface, available for the taking. Fortunately for us.

The home oxygen runner-pat describes is not bottled oxygen but rather oxygen concentrated from the air, right before you use it.

I’m pretty sure oxygen isn’t prepared for bottling by chilling it to below oxygen’s boiling point. I think it’s done under a great deal of pressure, at a much higher temperature. That would actually be a boiling temperature for oxygen, too, but not the one people normally mean when they say “the boiling point of oxygen”. For one thing, if you start with air and chill it, the water freezes out and plugs up your system, and a little while later the carbon dioxide would have done that too.

[Napier]

Here is a little more explanation:

http://www.madehow.com/Volume-4/Oxygen.html

It says oxygen is produced by fractional distillation of air, but at 94 psi, not at atmospheric pressure, so it would not be as cold as the boiling point of oxygen. Though, I am surprised the pressure is this low. I would have guessed it was done at 2000 psi or so.

[Joey_P]

@runner pat

My wife is on home oxygen. This is how it works. The same machine is also used to fill bottles for use outside the house.
I don’t know if the same system is used commercially.

My grandmother had one like that. I remember they had to keep it in a back bedroom partially because it was loud but also so they could close the door and open a window because it got pretty warm and that way it didn’t heat the house.

My Ex’s grandfather, being the tinkerer that he is, ran oxygen tubes all over his house so he could plug a tank in at one central location and his wife could plug in where ever she was instead of lugging a tank all over the place.

[hibernicus]

@Napier

Here is a little more explanation:

How oxygen is made - material, manufacture, making, history, used, processing, parts, components, steps

It says oxygen is produced by fractional distillation of air, but at 94 psi, not at atmospheric pressure, so it would not be as cold as the boiling point of oxygen. Though, I am surprised the pressure is this low. I would have guessed it was done at 2000 psi or so.

Never mind