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Author: Subject: Birkeland-Eyde reactor for making nitric acid.
hissingnoise
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[*] posted on 1-12-2009 at 12:41


In air, NO is formed at ~3000*C--- NO is fairly stable below 600*C but dissociates above this temperature.
Rapid cooling of the gasses is essential to minimise NO losses. . .
The area outside the arc plasma should be 'cool'!
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[*] posted on 5-12-2009 at 12:23


Quote: Originally posted by PolarSmokes  
and Kclo4, I'm guessing he would add it to water, to make nitric acid and nitric oxide, with the nitric acid being what he is after. I'm just taking clues from the context of the general idea of this thread! I could be wrong, though!


But then there isn't any point in condensing it... is there?




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[*] posted on 5-12-2009 at 12:31


Quote: Originally posted by Sedit  
Do you know of any attempts at modifying a Microwave oven to make a Birkeland-Eyde reactor? This seems like it could be a pretty efficient means of producing given the large area of the plasma.


Yes, a microwave horn would be ideal for powering the plasma. The downside is you might blow up a lot of magnetrons getting the SWR low enough.

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I have a question perhaps some can answer. When I use to play with HV alot one of the ways to tell the amount of power was to look at the spark. Its lenght gave alot of information of the Voltage present and its color gave info about its current. It was said that if the color was blue then that was from it fixing nitrogen in the air. Now I don't remember what exact numbers these where suppose to denote but wouldn't a blue spark instead of the hot yellow plasma yeild a higher concentration of NOx gas?


No, blue is from oxygen. The oxidizing odor is from ozone, not NO2.

Quote:
I do know that I would encase the spark gap of my Tesla coil and only after a few seconds of running the who inside would be coated brown from Nitrogen oxides.


Yes, the spark gap carries high current, so it has a heavy, thermal arc which burns the air, forming mixed products, NOx included. On the other hand, the blue to purple discharge from the secondary terminal mostly produces ozone (unless you draw arcs from it).

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[*] posted on 5-12-2009 at 17:57


If you powered such a reactor with microwaves, would you somehow need to 'seed' the plasma, to get it started, for example with a small electric arc? Isn't air fairly transparent to microwaves, after all you don't get spontaneous plasma formation in your microwave oven.
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[*] posted on 5-12-2009 at 19:53


Yes. You need a special type of waveguide which concentrates the electric field, inducing breakdown. Otherwise, I'm sure you could, for instance, run plasma off a candle inside a regular oven.

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[*] posted on 8-12-2009 at 05:02


Quote: Originally posted by kclo4  
Quote: Originally posted by PolarSmokes  
and Kclo4, I'm guessing he would add it to water, to make nitric acid and nitric oxide, with the nitric acid being what he is after. I'm just taking clues from the context of the general idea of this thread! I could be wrong, though!


But then there isn't any point in condensing it... is there?


Yes. The point is absorption from the water. When nitrogen dioxide is in the gas phase, it will leave the nitric acid by bubbling up because it is a gas. If it is condensed, it is allowed to react with water for a much longer time. it still dosn't help with H2O + 3NO2 --> NO + 2HNO3, but it will still allow the initial NO2 formed to be converted into NO2.

As the the microwave ideas, what are you guys planning to store them in? It will easily burn through the top of the glass. Or if you're using metal, the bulk of the power will be delivered to the container. As far as methods of ignition, if you want to be elaborate, you could probably get away with YAG induced blooming, as a "seed" for the plasma, without any wired contacts, however, a laser powerful enough to cause air to bloom will burn through glass.

I get my paycheck soon, and it's pretty cold outside, (which can be used to the advantage of my tec unit), so I might try to work out a setup that allows me to test MOT vs NST vs ZVS flyback driver, to see which one produces the most N2O, overall, and subsequently, nitric acid.

OR, I may get an oxygen compressor to hook up to my oxygen concentrator, simply because the concentrator costs too much to keep running for 1lpm, when I could fill a tank in a few hours, which would be able to provide 1 lpm for hours.... Are you guys using just air, or air and concentrated oxygen?

People working with the microwave induced plasmas, let me know how it is going!
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[*] posted on 9-12-2009 at 17:08


I'd also like to add - consider if you were to want 100% HNO3 - take 70% nitric (Easy to get) and put some N2O4 in it - not only will the 70% NOT be frozen at the appropriate temperatures, but production of (nearly) 100% nitric is almost trivial. White fuming 100% HNO3 it probably would not be, however.
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[*] posted on 29-3-2010 at 07:35


Just an other information, hope it help.

"Catalytic oxidation of NO to NO2 over activated carbons PAN-ACF, pitch-ACF and coconut-AC at room temperature (30°C) were studied to develop a method based on oxidative removal of NO from flue gases. For a dry gas, under the conditions of a gas space flow rate 1500 h−1 in the presence of oxygen of 2–20% in volume concentration, the activated coconut carbon with a surface area 1200 m2/g converted about 81–94% of NO with increasing oxygen concentration, the pitch based activated carbon fiber with a surface area 1000 m2/g about 44–75%, and the polyacrylonitriale-based activated carbon fiber with a surface area 1810 m2/g about 25–68%. The order of activity of the activated carbons was PAN-ACF<pitch-ACF<coconut-AC. However, NO conversion markedly decreased with the increases in temperature and humidity. For the dry gas, the apparent reaction rate was expressed by an equation: R=kcPNOPO2β (F/W), where β is 0.042, 0.16, 0.31 for the coconut-AC, the pitch-ACF and the PAN-ACF respectively, and kc is 0.94 at 30°C."

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[*] posted on 1-12-2010 at 05:22



related threads
http://www.sciencemadness.org/talk/viewthread.php?tid=4092
http://www.sciencemadness.org/talk/viewthread.php?tid=1013

The following is a source for papers on Plasma Chemistry some specific to the topic of
nitrogen dioxide , and others to ozone production. Many more applications are covered.

International Symposium on Plasma Chemistry - Digital Archive
http://134.147.148.178/ispcdocs/index.html

When only abstract is given , Conference Full Papers are found here
http://www.iupac.org/publications/pac/conferences/family/ISP...


Some excerpted papers are cited here , the later conferences have hundreds
________

Symposium 3
http://134.147.148.178/ispcdocs/ispc3/DB2.html

On Experimental Study of Nitric Oxides in Microwave Plasma
http://134.147.148.178/ispcdocs/ispc3/content/3/03-G.1.6.pdf

________

Symposium 4
http://134.147.148.178/ispcdocs/ispc4/DB2.html

See List of this Topic Heading - Specialized Session on Ozone Production

________

Symposium 5
http://134.147.148.178/ispcdocs/ispc5/DB2.html

Nitric Oxide Production in an Atmospheric Pressure Microwave Air Plasma
http://134.147.148.178/ispcdocs/ispc5/content/5/05-0761.pdf

The Influence of Gas-Inlet & Quenching Systems on the Nitrogen Oxides
Production in Air Plasma
http://134.147.148.178/ispcdocs/ispc5/content/5/05-0756.pdf

Also See - Session 6: OZONE SYNTHESIS
http://134.147.148.178/ispcdocs/ispc5/DB2.html

________

Symposium 6
http://134.147.148.178/ispcdocs/ispc6/DB2.html

Nitrogen Oxides Direct Synthesis in a Low Pressure Plasma Obtained From a
Microwave Discharge

http://134.147.148.178/ispcdocs/ispc6/content/6/06-0242.pdf

________

Symposium 7
http://134.147.148.178/ispcdocs/ispc7/DB2.html

The Corona Discharge, Its Properties and Specific Uses
http://134.147.148.178/ispcdocs/ispc7/content/7/07-0016.pdf
________

Symposium 9
http://134.147.148.178/ispcdocs/ispc9/DB2.html

High Power Glow Discharge for Chemical Synthesis
http://134.147.148.178/ispcdocs/ispc9/content/9/09-1737.pdf

.
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[*] posted on 8-12-2010 at 22:03


http://jennwork.homelinux.net/drupal6/node/3

Do not know if anyone has read this page. Well worth a read. Nice work on both the pebble-bed plasma reactor system and the effort to determine concentration.


Mods, this thread deserves a sticky.




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[*] posted on 21-7-2011 at 07:27


Quote:

Mods, this thread deserves a sticky.


So true!

I'm really impressed with how viable a microwave generated plasma system for synthesis of NO2/HNO3 looks.

Here's my dream design:

Use a standard air compressor to supply the reaction with ~100psi air. The energy cost of compressing the air is minimal, on the order of 20w/m^3/h of atmospheric pressure air compressed to 100psi. Of course the compressor itself is expensive, but many already have access to them for other purposes. And for small personal use amounts of HNO3, a very small cheap compressor would provide plenty of air.

The reactor would consist of one or more microwave oven magnetrons attached to the necessary waveguides which concentrate and focus the microwaves on a air inlet nozzle. The waveguide and reaction chamber design will no doubt require the most R&D for me. If anyone has references useful in the design of waveguides I'm sure many would appreciate them being posted.

Directly after the pressurized air stream has passed through the plasma it would be expanded through a simple converging-diverging venturi nozzle. Cooling water would be sucked into the nozzle to aid rapid cooling. Or it could be pumped in upstream of it, etc. According to various references, if the venturi is sized correctly cooling rates of over 10^7K/s are achievable. That means over 75% possibly up to 90% of the NO formed will remain undecomposed upon cooling. Hopefully the amount of cooling water added could be kept close to the amount needed to form your desired concentration of HNO3.

The freshly cooled expanded gasses would then be passed at a slow rate through a column of activated carbon to allow the reactions that form HNO3 to run to completion.

Based on the papers linked above and others, I calculated that one standard size magnetron should be able to yield at least 1kg of HNO3 per day. If cooling rates and wave guides can be optimized it could be even higher. At my power prices that comes to about $3.50/kg HNO3. The compressed air needed is minute, on the order of 0.1 CFM@100psi. Considering it should provide very high purity HNO3 and the system would require little attention and almost no materials would be consumed, I think it looks pretty damn good! Oh and it should be pretty easy to scale up :D

Besides making HNO3, I think the NO(2) produced could have many other interesting uses. Panclastites anyone? And oxidation to N2O5 looks extremely appealing too.
I can't begin to put into words how unhappy it makes me to realize I won't have a chance to try this out for quite a long time..

On a less related note, I found it interesting that running methane through a plasma then rapid quench process can achieve good yields of acetylene and hydrogen. I wonder what other fun things could be done with one?
Refs, refs, and more refs.

[Edited on 21-7-2011 by 497]
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[*] posted on 21-7-2011 at 07:46


Quote:
I can't begin to put into words how unhappy it makes me to realize I won't have a chance to try this out for quite a long time..

The longer you wait, the better the appreciation you'll have of the dangers involved!

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[*] posted on 21-9-2011 at 15:51


My goal isn't to make views, but here is my terrible how to, http://www.youtube.com/watch?v=xYrl8mPg8Ag
I will be updating this very soon as I get back more into chemistry.
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[*] posted on 5-8-2012 at 03:49


IMHO a critical problem with the Birkeland-Eyde is the low conversion of air, resulting in low concentrations of NO2 and problems with efficiently condensing/reacting the very dilute product.

This patent is a major step forward for small scale nitrogen fixation. http://www.google.com/patents?id=ehgaAAAAEBAJ&pg=PA7&...

Silica gel in a ~1% NO2 atmosphere at 15C will hold 6.5% by weight NO2 at equilibrium. According to the patent, in practice ~4-5% is the concentration achieved with 5% loss of NO2 through the bed of 10-14 or 6-8 mesh silica gel. They say with a silica gel bed 3 feet high, and flow velocity of 100 ft/min, 100% of the NO2 is caught for 12min then efficiency drops off till it is catching 75% after 30min. They say at this point the silica gel is 75% saturated, which I assume means 4.8%NO2. Over the 30min a total of 5% of the NO2 is lost through the bed. If the granular fill factor is .4 (slightly fluidized) and the silica gel has 1ml/g pore volume, the silica gel loading would be 22kg/sq ft of bed, which corresponds well at 4.8% NO2 to the ~1kg of NO2 that would be carried by the corresponding 50 cubic meters of 1% NO2 (calculated as pure monomer) that flow over 30min. I think the patent was calculating the NO2 content based on the original NO% by volume.

In the process they use, three silica gel beds are alternated between, so that they have 30min to reach full capacity, 30min to extract the NO2, and 30min to cool down. 75% of the NO2 content as 98% pure gas is extracted at 165C, then 180C air is blown in to pull out the remaining 25% as a ~20% mix with air (which is made into HNO3). This way they would need 500-600kg of silica gel sorbent in the cycle to process their NO synthesis furnace output of 375mol/hr NO. Thus with 900 cubic meters of air, 27 kg hydrocarbon fuel (enough to use up 38% of the O2), they are able to get 12kg liquid N2O4, 6kg HNO3, and 250-300 kwh usable heat energy per hour. That comes to 68 kwh per kg of N fixed. This is better than the original Birkeland-Eyde process, and only about 2-3 times the current state of the art plasma 10^8K/s quench rate N fixation systems. When you take into account the efficiency of electrical generation/transmission, using fuel starts to look even more attractive.

For the very small scale experimental N fixing system, no doubt a plasma system would be simpler than a scaled down version of this patent. Not having to meter fuel/air, cool and dry exhaust gasses, etc would make the entire thing very simple. All you'd need is an air pump, an air drying tube, a plasma reactor run by TV or neon sign transformer, and a silica gel chamber. Once silica gel is near saturation, shut down the plasma reactor and use the NO2/silica gel as you please. It is safe convenient to store NO2 in silica gel. It can added directly to a reactant as a more mild nitrosating or oxidizing agent than liquid NO2. It can obviously be reclaimed as pure NO2 gas upon heating. I can't find any refs that mention NO2/silica gel + ozone, but interesting things may happen if you passed ozone through it (alone or submerged in solvent/reactant.) On a small scale cooling the gas lower is more convenient also, so using winter temps, salt+ice, or a freezer would allow slightly higher yields from the plasma reactor, and much higher NO2 capacity for the silica gel. At -10C the silica gel may well hold >30% NO2. When prepared by adding excess NO2 to silica gel in DCM at 0C can attain 45% NO2 content AFTER vacuuming off the solvent, and its stable at refrigerator temps for months. I'd try this as my plasma reactor: http://www.google.com/patents/US4877589

I still think the combustion based system is exciting and worth exploring. If you wanted to make kg of NO2, where off grid, or had plentiful (possibly low grade) fuel and expensive electricity, it could be worthwhile. More experimentation required for sure. Personally, instead of using pebble bed heat exchangers to quench the >2000C flue gas, I'd try injecting water directly into a conventional high turbulence venturi burner. This is a known way to rapidly quench hot gasses, and may even improve the yield, while greatly simplifying everything. The NO in the flue gas reacts with O2 quite slowly at these concentrations, so only a <.5% of it is lost to the cooling water. Then dry the gas, run it over a small bed of NO2/silica gel to rapidly catalyze the reaction with O2, and then capture it in the main silica gel bed. Running batchwise would eliminate most of the complex automation in the patent. If you pre gasified your fuel in a crude updraft gasifier, any thing from waste plastic/paper to wood/coal could be used. Normally the vast tar production of updraft gasifiers makes them unusable, but if you directly burn the output before cooling that issue disappears.

In a cold climate you could easily be making >1 ton NO2/year while providing your household heat (and power?) for an extra 15-30% fuel consumption and 50-250kg silica gel. The colder it gets, the faster you produce NO2, but the colder you can cool the gas, and the more the silica gel will hold. Freezing brine tanks to "stock up" on cold during cold weather could allow the silica gel to be used at greater capacity for longer.
Beautiful!

I'll gladly consult anyone looking to build one.

[Edited on 5-8-2012 by 497]




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[*] posted on 5-8-2012 at 15:24


An ozone generator with moisture-adjusted air feed producing NO<sub>2</sub> and enough O<sub>3</sub> to oxidise the NO<sub>3</sub> to the anhydride would do away with the need for absorbents and produce, in theory at least, any concentration of HNO<sub>3</sub>!
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[*] posted on 24-9-2012 at 20:07


Just wanted to pop in here with a quick bit of info, as progress is slow. Recently spent some time thinking about and designing, and finally building my take on the concept of the Birkeland-Eyde reactor.

For reference, I used this thread, as well as numerous youtube videos and other websites. I also read "Absorption of Nitrous Gases" from the sci-mad library, front to back. Its actually quite a fascinating review, and I have found that I love texts from that period (1910s through 1930s). Other references of note are "The Electric Furnace" by John Norman Pring (starting at p.115); and "Industrial Nitrogen: the principles and methods of nitrogen fixation..." by Percival Henry Sydney Kempton (starting at p.13). Both are available on google books.

My first take was a failure, plan and simple. Insufficient volumes, inaccurate and unadjustable electrodes, etc. The second version appears to work, and has had two distinct runs.

First, a few brief descriptors of the device. I will go in to more detail should the device ever prove itself useful, but for now some generalizations should suffice.

I am utilizing a Jacob's Ladder style arrangement, with soft copper tubing 1/4" in diameter. The primary construction material is PVC pipe, which several references show as suitable for withstanding Nitric Acid in concentrations of less than 40% at STP. The material was useful due to the availability of a wide variety of sizes and shapes and the ease of construction, as well as its high resistance to electrical current.

The power supply for this was a 300W NST, which produces 10.5kV at 30mA. It is secondary ground fault protected. This power supply is probably quite underpowered for this purpose.

The device is operated under the low pressure and air current provided by a common aquarium air pump. The air is pumped directly into the arc from underneath to try and create a "flame-like" electric arc, which at 60hZ has visible break lines but still fills most of the space between the electrodes. This particular setup was decided upon after a failure to create a magnetically spread arc utilizing several large ferrous magnets, and the neodymium magnets more suited to the purpose were considered, for now at least, too expensive.

In the first trial, the device was run for 6 hours at 50% duty cycle with a frequency of one on/off cycle per ten minutes. Distilled water (500mL) was used as absorbent, followed by a container of 10% NaOH solution. Some nitrogen oxide smell was noted so the fume hood was used for this and all further tests.

The result is a solution which appeared, on titration with 1M NaOH solution, to contain 0.14% acid. I estimate the potential error in my measurements, based on titration of a known quantity of Acetic Acid (household 5%) to be as much as 10%. Thus I feel comfortable stating that the solution contained between 0.13 and 0.15% acid. Given these extremely low concentrations, I don't have any particular way of determining whether or not the acid is in fact HNO3.

For the second trail run, I changed several things. I used 500mL of commercial 3% H2O2 solution, the air flow was slightly reduced, the frequency of the on off cycle was changed to 30 minutes (after determining that the electrodes wouldn't get too hot to damage the pvc during a 15 minute run), and the air flow was allowed to continue during the off portion of the cycle, where previously it had been shut off concurrently with the arc.

This setup was ran for approx. 12 hours. Approximate because the digital timer used to run the first one died, probably from electrical feed back from the NST. A mechanical timer was used for the rest of this run.

Titration showed an acid concentration of 0.84%, which seems to be 2 to 3 times better than the previous run.

What I took away, given the continued prevalence of nitrogen oxide smell even post secondary hydroxide laden filtration, was the need for better absorption in the "main tower". While I would love to follow the authors advice in "Absorption of Nitrous Gases", I think I may have to stick with a loose packing such as broken glass or pumice. Pumping the absorbent to the top of the tower to counter-flow against the nitrogen oxides along even, symmetrical and high surface area packing proved to be a bit too much to construct.

If I had some serious glass working skills and an annealing oven, I have ideas and designs for a magnetically spread arc, pauling lift operated, positive pressure Birkeland-Eyde made out of all borosilicate. At least I can dream ambitiously. :P




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[*] posted on 25-9-2012 at 03:13


Pictures?
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[*] posted on 25-9-2012 at 10:33


I am waiting until I have useable, practical results before posting a proper write up.

After the dismal failure of mk I, I was in a focused head space while constructing mk II and didn't think to document the process as I went. Nevertheless, I plan to take pictures of the current model should it prove useful, and I have several tips still in mind regarding its construction. If a total redesign is called for, then I will document the process of building the new one.

However, here is a picture of the current state of things.


proto.jpg - 112kB




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[*] posted on 25-9-2012 at 12:15


I used an old sweet jar (many, many moons ago); it was inverted so that aluminium electrodes and tubes could enter through the large bakelite screw cap.
Two NSTs in parallel drove the dischage and a 'fridgepressor the 'air' supply!
This, unfortunately introduced an oil-mist which coloured the acidic solution produced yellow!
The coloured impurity was a nitrated paraffin mixture . . .
Its presence indicated a loss of NO<sub>2</sub>!
A clean compressor would have given fairly pure acid.
The aluminium tubes were scavenged from an old freezer and they were used because pure Al is practically inert to dry NO<sub>2</sub>.
Aluminium electrodes were used for the same reason.
Epoxy glue was used as a sealant ─ it survived the harsh conditions for quite some time, but the seals needed renewing fairly regularly.
The effluent was led to continuously stirred water in a tall flask where absorption occurred . . .
Having the discharge occur behind glass is very convenient as the arc can be seen so that that electrodes may be adjusted to produce an optimum discharge.
Seeing the amber colouration intensify in the jar on start-up was interesting too.



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[*] posted on 25-9-2012 at 13:15


I originally set up the electrodes inside an inverted glass tea jug (1 US gallon), to prove to myself that NO2 was in fact being created (it was). I also took some time to optimize the distance between the electrodes while under the influence of a flow of air. The electrode placement I am running with is set so that without the influence of air flow the arc will not climb the ladder (for consistently reliable arc formation), and under the influence of air flow the arc snaps at an average of 3/4 the way up the electrodes. I decided on this for two reasons, one being so that the plasma arc would be less likely to come into contact with the flammable PVC walls, and two so that the extra copper could act as a mass heat sink to slow the heating up of the electrodes.

I chose copper on the recommendation of "Absorption of Nitrous Gases", but also because it is easy to shape and is of course a good conductor of electricity and heat.

Just out of curiosity, what were the electrical ratings on your NSTs?

What I would like to do is run my set up 24/7 (15min on, 15min off) for the next two weeks. Unfortunately, due to the nature of the construction materials and my inability to constantly supervise it, I think that would be dangerously unwise.



[Edited on 25-9-2012 by Natures Natrium]




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[*] posted on 26-9-2012 at 05:02


Quote:

I chose copper on the recommendation of "Absorption of Nitrous Gases", but also because it is easy to shape and is of course a good conductor of electricity and heat.

Just out of curiosity, what were the electrical ratings on your NSTs?


Hmmm. . . I'd worry that Cu would be attacked by NO<sub>2</sub>.
The NSTs, with centretaps at ~5kV had ~10kV outputs ─ current output long-forgotten . . .
Connecting in parallel increased arc temp and length!

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Dave Angel
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[*] posted on 28-9-2012 at 16:02


Quote: Originally posted by hissingnoise  
An ozone generator with moisture-adjusted air feed producing NO<sub>2</sub> and enough O<sub>3</sub> to oxidise the NO<sub>3</sub> to the anhydride would do away with the need for absorbents and produce, in theory at least, any concentration of HNO<sub>3</sub>!


I do not wish to derail this design exchange - hissingnoise's concept of producing anhydrous HNO3 got me thinking.

Regarding absorption of NO2, what if one were to run the output from a B-E reactor into a solution of hydrogen peroxide in a suitable organic solvent? Here's the envisioned reaction, does it seem reasonable?:

2NO2 + H2O2 -> 2HNO3

The following image shows the first page of an old JACS article (J. Am. Chem. Soc., 1916, 38 (3), pp 633-638) alluding to the solubilities of H2O2 in various organic solvents - work performed by mixing aqueous peroxide with the solvent:

Walton & Lewis.png - 251kB

Wikipedia suggests that mixing a suitable dry solvent with sodium percarbonate, would take the peroxide into solution, as others have noted in posts regarding sodium percarbonate. The reference wiki used (Tetrahedron Volume 51, Issue 22, 29 May 1995, Pages 6145–6166) would be handy and I'll track it down when I'm next at the library.

Now, of course we have the dreaded mix of organics and peroxide so selection of solvent would be critical, and not something within my experience, so this is very much an entertaining thought experiment rather than and experimental plan for me, but I felt it worth sharing.

The point is that the nitric acid formed is likely to be near anhydrous, and could be isolated by either evaporation of the solvent or freezing out with dry ice.

Any thoughts?




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offset442
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[*] posted on 19-10-2012 at 13:35


I have been using one of these reactors to produce 40% HNO3 and nitrate salts for over a year now, works good have little problems with absorption, I have found absorption to be even efficient when no bubbler is employed,

My you tube video is here
http://www.youtube.com/watch?v=Owl0KjSro-Y&feature=youtu...

I have produced about 10 liters of 40% and 2 kgm,s of salts, gave up on the ozone generator for lack of cheaply available materials that would stand up to it ie Teflon etc... (poly vinyl peroxide yuck) currently I have replaced the 2 neck flask with a 1 gallon glass wine jug and have about 1kg of lead reacting, conversion rate is good it will be completely converted in about 30 days pushing a 240 watt arc with no agitation.

I have to issue a warning, if making lead nitrate, pure lead is required, as any tin will make basic tin nitrate under these conditions, a sensitive high explosive' this material can be filtered away, but would be best not to deal with.

Would love to find ways of producing a better o zone source as it allows for direct nitrations and production of con hno3.

This setup goes a long way toward the production of anodes :-)

I find 40% acid to be a most convenient strength for general use, as well purity is at or above reagent grade dependant upon conditions
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[*] posted on 20-10-2012 at 00:14


At offset442: You should make a doc describing your setup - dimensions - air pump - power usage - time of reaction - yields etc - it looks very interesting and it would help others collaborate with you.

There was one more birkland generator using neodymium magnets for spreading the arc but looked a little slower at oxide production.

http://www.youtube.com/watch?v=2RRqIv4SoLg

[Edited on 20-10-2012 by jimmyboy]
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offset442
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[*] posted on 20-10-2012 at 07:43


That is the first attempt at a real B.E. reactor, as impressive as it appears this is not a very practical device, though is does appear to be producing fuming hno3, I have my doubts that this reactor is doing any better than mine as to acid concentration I think this setup is getting h2o from the air compressor as condensate. Also you notice the tungsten electrodes are coating the inside of the glass, likely with some sort of nitride, I get the same deposits from my iron electrodes in my Pauling arc chamber. This device represents an accomplishment however I would not trust it to run for almost 1 year straight with little supervision

Most notably the volume of acid it generates , it seems from the video that it could generate acid in the range of liters per day while my setup generates in liters per month, though I'm not saying that you couldn't use my rig, up scaled to an equal powered arc and get the same volume of production, Pauling had very good results with horn electrode furnaces made from bricks, with conversion effencies within a few % of birkeland

The main thing when designing a rig like mine is not to over power it without having a way to safely dissipate the heat of the arc, I feel my rig would fail if i went from 240 w to 450w the difference between 9kvac and 15 kvac even though my containment rig is made of Pyrex, asbestos, steel and cermanic tile. it uses automotive quark gasket and surgical vinyl tubing, in a wooden cabinet

For higher power levels, such as that of say a mot ,a steel cabinet is required, as well as stainless 316 ss tubing I would avoid using a organic materials for sealing, perhaps high temp fiber glass re enforced, silicone sheet often seen in automotive applications . I would also upscale the chamber siz. , perhaps getting rid of the pyres glass jar and going to a steel cylinder of some sort with a window installed.

That's it for not the wife calls :-)
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