[Linz1607]

Hi Folks, i have an issue with oxygen generation as the byproduct of using a nitrogen membrane system, we need the nitrogen , but the oxygen waste product also needs to be captured or converted , ideally into an inert gas, we cant burn it, as we are potentially in a methane rich atmosphere. Is it possible to convert the free oxygen into sometime harmless ? I have water, nitrogen, air and a limited amount of electricity available, for the process. One thought was to build a big oxygen absorber (iron dust, salt and water) but the obvious limitation is reached at saturation point.

Lindsay

[Arkcon]

Hmmm ... tricky.  OK, so you want some sort of chemical reaction, catalytic I'm guessing, to chemically reduce oxygen in situ.  What else is available for the oxygen to react with?  Is there enough methane for that?  You'll get CO₂ and water.  Is that OK for your application?  Doesn't the nitrogen membrane do a good enough job of getting out the oxygen?

Just an FYI "converting" and element to an "inert gas" sounds very weird, you wanted some sort of flame-less chemical reaction.  And oxidized compounds aren't really "inert" just relatively "non-reactive."  As written, your question sounds pretty odd.

[Linz1607]

Hi Arkcon

The methane is not always present, if i could guarantee a methane free environment, we could burn off the oxygen in a controlled manner, but the methane may be present. The oxygen must be captured or converted or just piped away. Sorry for the odd question, poorly phased.
 My machine will deliver nitrogen using a membrane system to extinguish a fire, so the elimination of the oxygen is important, as the membrane system is located close to the ignition source.

[DrCMS]

Why not just pipe the exhaust oxygen enriched air from the membrane system to a safe distance from the methane source.

[fledarmus]

You could always blanket the system in Halon. This will quench any free radicals that form and prevent a fire.

 

[curiouscat]

What sort of rates of O2 generation are we talking about? Will the system continuously make N2 or only a spike in response to a fire?

Wacky idea but would Hydrazine work? Or too dangerous?

N2H4 + O2  H2O + N2

More N2 for you? 

Another idea:

2 Na2SO3 + O2 → 2 Na2SO4

Also Methylethylketoxime reacts with O2 to give MEK.

I've seen these for Boiler O2 removal but that's at ppm levels; not sure if it'd suit your need.

In H2O2 manufacture there are anthraquinone derivatives that are sequentially oxidized and hydrogenated.   You could try to do half the cycle and oxidize the anthrahydroquinone and accumulate the anthraquinone?

Keep in mind I'm only speculating; maybe these are all duds.