FKT: HONO2 The inconcievable

[James]

A43tg37 posted on May 13, 2002 at 06:40 PM
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"><center>NITRIC ACID PRODUCTION</center>
U.S. Patents
4,141,715-Method and apparatus for producing nitric acid via an electric arc
4,010,897-Method and apparatus for home production and application of nitrogen fertilizer
4,873,061-Fixation of nitrogen by solar energy
The first two patents are designs (essentially based on the Birkeland-Eyde process) for cheap home or farm based devices that can produce nitric acid via nitrogen oxides, using only air, water, and 110V electric power as raw materials. The second is of little concern as far as fixation by solar energy, but is more interesting for its mention and description of the "pebble bed process" which makes use of tungstic oxide catalysts instead of precious metal ones and actually burns air over a superheated medium to create nitric acid.</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">If all else fails I suppose Ostwald could be used, but I think it's impractical for less the 90tons/day. Links and stuff will come later.

[Ollie Snowie]

Hmmmm...
Lightbulb filaments are tungsten... They get quite hot...
You guessed it! You'd carefully smash the glass aroung two lightbulbs, and wire them in series to stop the filament getting too hot and corroding all the way through. Then you'd mount them so the filaments are as close together as they can get without touching, and suck air past them. I'm gonna try this.
PS - Funny that I used the lightbulb icon, considering what the post is about :D

[EDIT -
I have just tried this, and (not surprisingly) it proved very difficult to regulate the current so as not to burn the filament.
Still, a tungsten mesh could also be heated to a high temperature by a very high current flowing from a rod in the center to a ring round the outside. This way a very high temperature would be created at the center or the disk, while the edges of the disk would be at a much lower temperature. Air could be pumped in from the sides of the apparatus and sucked out through an array of small water cooled pipes at the center. The air would be heated gradually to a very high temperature and then suddenly cooled, forming nitrogen oxides.]

[Marvin]

Thats a good idea, its a shame it cant work. Regulating the temperature of the filiments isnt the problem, the problem is that at the temperatures you need to make nitric oxide, tungston burns in air. Unfortunatly theres no way round this as you cant avoid having oxygen in the gas mix. Coating (plating) the filiment with platinum might possibly help but I doubt it would work well enough to be useful.

[Ollie Snowie]

Platinum wire is used as resistance wire in high temperature furnaces (apparently) so that's another thing to look out for at the scrap yard :) .
Another thing I found strange while studying the patent was the mention of ammonia production when water vapour, nitrogen, and a suitable calalyst come together at a high temperature in the presence of light.
Another thing I'm wondering is how the filaments in halogen bulbs can stand the hot halogen and not corrode. Just from a quick glance the filaments in halogen bulbs look thicker than those in mains light bulbs. I suppose another explaination for this is that they take a lower voltage so they need to be thicker/shorter to allow enough current through.
I never thought that platinum was a suitable catalyst for the burning of nitrogen in oxygen, but I know that is is very good at oxidising ammonia. Will someone please clarify this.
In the patent is says that titanium dioxide will calalyse the reaction of water with nitrogen at a high temperature to make ammonia and, I suppose, oxygen. This mixture could be passed over a heated platinum catalyst so some of the ammonia would be oxidised (eventually and finally) to nitric acid, and this would neutralise the left over ammonia. I have the feeling that the excess ammonia would just be decomposed into nitrogen and hydrogen by the high temperature. Will someone please clarify this as well.
Ammonia is also needed for some preps as well as nitric acid, but you can make a great deal more variety of explosives with nitric acid than ammonia, and this was a thread about nitric acid, after all.

[EDIT - I'm also thinking along the lines of:
(arc welder=power supply)+(tungsten welding rod hammered flat=resistance wire+catalyst)-->setup for making nitric acid.
As well as:
Tungsten screen is placed in front of magnetron from microwave oven for intense heating.
And:
This is getting too similar to another thread involving microwave heated catalysts and air.]

[Tuatara]

Not strictly on topic but ...

The halide in tungsten halide lamps is iodine. The filament is usually run hotter than in a standard lamp, so the evapouration rate of the W is higher. The W combines with the iodine to form tungsten iodide. Tungsten iodide will decompose when heated, into W metal and iodine again. So the iodine acts to sweep up any W vapour, then redeposits the W back on the filament, mostly at the hottest point (the thinnest point), thus extending the life of the filament. Neat trick, eh?

[Chemical_burn]

Very intresting indeed. I believe the toungesten filaments in florsent(sp?) lights it very tought as I have broken these lights before and removed the filiment to use in electric ignitors and they are very thick and heavy for a filiment. There are two filiments in one light one on each end in the contacts of the bult.

just though I would see if it helped any.