preparation of nitrogen

[the guy]

I need to produce a nice steady stream of pure nitrogen for and experiment.

 

Could anyone suggest the easiest (both in method and in availability of materials/chemicals) and safest method for preparing nitrogen for this?

 

thanks in advance

[weiming1998]

Combine a dilute solution of sodium nitrite (any nitrite, actually) with an ammonium salt, then very slowly heat the solution until the rate which the nitrogen is produced is fast enough (overshooting with the heat can lead to vigorous decomposition, even explosion).

 

Combining ammonia solution with calcium hypochlorite will also produce nitrogen, but it will be contaminated with large amounts of chloramine.

[Enthalpy]

Normal people get liquid nitrogen from sellers and let it evaporate as needed. It's naturally clean, cheap. Borrow some from the next university or lab. You might obtain it gaseous in a pressure bottle as well.

 

I wouldn't consider chloramine as safe, since it's a precursor to hydrazine. Nitrite neither.

[John Cuthber]

Air and ammonia passed over a hot catalyst will give wet nitrogen (with a little argon etc).

It's difficult to avoid the production of NOx which may be a problem.

[weiming1998]

Normal people get liquid nitrogen from sellers and let it evaporate as needed. It's naturally clean, cheap. Borrow some from the next university or lab. You might obtain it gaseous in a pressure bottle as well.

 

I wouldn't consider chloramine as safe, since it's a precursor to hydrazine. Nitrite neither.

 

Sure, chloramine isn't the safest thing around, but it's not extremely toxic either. Hydrazine can only be made from chloramine under special conditions (with a large excess of ammonia, low temperatures, and chelators or thickening agents). Simply working outside solves the problem of accidentally being gassed by chloramine. But if the nitrogen is used for inert gas purposes, this method won't work because chloramine is too reactive.

 

As for nitrites, wear gloves and safety goggles, and you're pretty much good. Again, it's not extremely toxic. The chances of an explosion is slim if the solution of nitrite+ammonium salt is kept dilute, even if you just cranked the heat up. With a dilute solution and careful, slow heating, the possibility of an explosion is almost non-existent.

[alpha2cen]

This is one of the N₂ separation method from air. This method uses very low temperature.

[CaptainPanic]

I need to produce a nice steady stream of pure nitrogen for and experiment.

 

Could anyone suggest the easiest (both in method and in availability of materials/chemicals) and safest method for preparing nitrogen for this?

 

thanks in advance

Buy it.

Just get a nitrogen cylinder (it's essentially a pressurized bottle of nitrogen) with a gas pressure regulator.

 

This is the method that everybody uses in the lab. Nobody makes nitrogen.

 

Nitrogen is essentially a waste product from oxygen production (which is what alpha2cen described in the post above) - and it's pretty cheap. Renting the cylinder and the regulator, as well as delivery to wherever you need it, may still result in some costs.

[alpha2cen]

Other method is PSA(pressure swing adsorption) method. This method uses MSC(molecular sieving carbon). MSC contains very small nano pores in it. Large molecules movement in the pore are more slow than small molecules for their size.

Edited November 16, 2012 by alpha2cen