Sciencemadness Discussion Board - Nitric acid by Electric arc !

Nitric acid by Electric arc !

fuse123 - 26-10-2006 at 07:24

somewhere...... i hear that we can make
NO2 gas by using electric arc in the air
& desolve collectting gas in water.
Is this right?and how?

Swany - 26-10-2006 at 07:26

Not NO2, specifically. Yes, it can be done. I belive it is called a Birkland-Eide (spelling) reactor and there is a thread in the technochemistry section and it was sucessfully applied by member Axehandle.

Search.

Elawr - 26-10-2006 at 07:38

Yes, indeed it can. A hot electric arc through air is required. The cold type of corona discharge produced for ozone or ion generation will not work. What you need is an HV supply such as a neon sign transformer (NST) capable of outputing around 12kv at 30 ma. NSTs are relatively inexpensive yet robust enough to dissipate a few hundred watts across an arc for the considerable length of time required ot generate usable amounts of NOx.

I think there are earlier threads here on this including details on how to actually set up and use such an apparatus.

fuse123 - 26-10-2006 at 07:38

wow maximum speed

Thanks SWANY
I need to know tha method to do it step by step
tell my wher
Any links
thanks again

fuse123 - 26-10-2006 at 07:44

thak you ELAWR
but where are the links

Swany - 26-10-2006 at 07:45

https://www.sciencemadness.org/talk/viewthread.php?tid=1518

You can find the rest yourself.

fuse123 - 26-10-2006 at 10:07

I do it
it takes 2 hours to read it
But at the end ..... no one fom them can
made practical reactor
Oh i'm frustration

not_important - 26-10-2006 at 15:00

Quote:

Originally posted by fuse123
I do it
it takes 2 hours to read it
But at the end ..... no one fom them can
made practical reactor
Oh i'm frustration

Welcome to the wonderful world of research, where you travel to when you want to do something out of the ordinary.

The arc method really only works well on a fairly large scale. On a small scale, if you can tolerate the inefficiency, just about any arc set-up will work so long as you can collect the gases that have gone through the arc.

fuse123 - 27-10-2006 at 03:00

Quote:

Originally posted by not_important
Welcome to the wonderful world of research, where you travel to when you want to do something out of the ordinary.

The arc method really only works well on a fairly large scale. On a small scale, if you can tolerate the inefficiency, just about any arc set-up will work so long as you can collect the gases that have gone through the arc.

maybe
But what about MORVAN saying " NO is produced thermally"

not_important - 27-10-2006 at 07:29

Quote:

Originally posted by fuse123
maybe
But what about MORVAN saying " NO is produced thermally"

It is. I said 'just about any electric arc', meaning nice hot sizzling spark. Most of the work in the commericial processes is to get the arc fanned out into a thin flame, and to blow air through that at the proper rate, all to minimise the amount of energy used per mole of nitrate produced. It is a thermal process, the arc gives quick heating and as it is thin also makes it easy to quickly chill the products to preserve as much of the oxide as possible.

For something you can fit on a benchtop, the total conversion rate isn't going to be huge, but neither is the power consumption. Concentrating on a arc that doesn't erode the electrodes too fast, and can be arranged so that air can be pulled through it and into an absorbing setup, is plenty. Turn it on and let it run for a few weeks sort of thing.

Again, that is 'arc', not electric discharge as in corona discharges and the like.

fuse123 - 27-10-2006 at 08:49

Quote:

Originally posted by not_important
Again, that is 'arc', not electric discharge as in corona discharges and the like.

My god
another frustration :mad:

what the different between 'arc' & ' discharge '
What i know is that any (arc or discharge ),that's mean high temp <+3600C>

12AX7 - 27-10-2006 at 09:50

Not really, you can easily ionize gas without it being exceptionally hot. Corona discharges are not very hot. Arc discharges (as used in welding, for instance) are thermal plasmas and emit a lot of black-body continuum as well as spectral lines.

The reason being the high stability of the N2 molecule and the high density of oxygen in air, which ionizes much easier. You can push your choice of electric "sandblasting" agent through the air, in other words electrons, and they'll batter anything in their path, but in so doing, as soon as they get any energy (say, 5eV), that energy will be released in dissociating O2, preventing the electrons from gaining enough energy to split N2. A thermal arc is used because, although it can't dissociate N2 to any appreciable extent (like...say...10%!), a little is better than nothing at all. This is a consequence of quantum mechanics and thermal statistics.

Tim

franklyn - 27-10-2006 at 17:00

http://www.sciencemadness.org/talk/viewthread.php?tid=6717#p...

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