How to remove O2 from air?

[bio]

Does anyone know a good way to remove O2 from air? I once read a procedure using a slow air flow over rusting steel wool but can't find it now. Fe makes several oxides you see. I need a way that will make a small continuous flow relatively O2 free to eliminate the inert gas bottle.

[demorol]

Why don't you buy nitrogen gas cylinder. It would be easier and cheaper than removing oxigen from air.

[bio]

Yes, except I have to drive 250 miles to get a refill. The method I mentioned is cheap, from JChemEd I think. I never did try it but it was something like putting a few kilos of steel wool in a sealed container after dampening with a little H2O. I just don't have the details anymore so I'm not sure one pass would work etc. All I need is about the equivalent of a small aquarium bubbler flow rate and the removal would not have to be very complete to work as it is an oxidation reaction anyway. Tube furnace at 450deg.

[Vitus_Verdegast]

Taken from: Mellor's Modern Inorganic Chemistry, revised ed. by G.D.Parkes, 1963 p 422 :

Nitrogen is easily obtained from air by removing the admixed carbon dioxide and oxygen. Carbon dioxide is removed by passing the air through a solution of sodium hydroxide; the oxygen is then absorbed by means of an element which will form a non-volatile oxide. Copper turnings are generally considered best for the purpose; the "turnings" offer a large surface of oxidizable metal to the air. The process is as follows:

Air freed from carbon dioxide in a wash-bottle of sodium hydroxide, and from moisture by passage through sulfuric acid, is then passed through a red-hot tube containing copper turnings. The copper removes the oxygen and forms cupric oxide:

2Cu + O₂ ^__> 2CuO

The nitrogen passes on to be collected in a gas jar, or gasholder, etc.  (Cold boiled water should be used in the gasholder as to lessen the risk of contamination owing to the presence of oxygen dissolved in ordinary water.)

[bio]

OK, Vitus thankyou. That would be doable but a little more trouble than I had in mind. It's great living in the boonies except when you need speciality items. Chems are no problem cause I order every few months and make a special trip. The PhCHO from PhCH3 gas reaction was great because the O2 from air was the oxidizer. Great yields also. Don't need to do that now because PhCHO is readily available here w/o the USA  List One nonsense. Look at my post in the methods forum for the patent vapor phase reaction for EtOH to EtNO2 using nitric acid. Still leary to buy EtNO2 as I'm pretty sure they ship it from the states.

[hest]

But for 100L air you oxidise ~60g Cu. Stick to the argon/nitrogene