Sciencemadness Discussion Board

Homemade Birkeland-Eyde reactor?

antimon - 19-10-2015 at 03:06

Hi, guys. I have some free time now i have an hour busride ahead of me. :)
I just have to ask and see if any of you have made a Birkeland-Eyde reactor yourselves?
I am asking because i recently found the thread on the Birkeland-Eyde process here on sciencemadness, and it seems like a very interesting process to me.
Also it is very hard to come by HNO3 these days, and it would be wonderful if you were just able to make it yourself at home. :)

I have googled it and i have read a bunch of stuff on it, and there are even a couple of clips on YouTube with people showing off their own homemade reactors, and that got me thinking about making one myself.

I have been working on a 555-timer ignition coil driver circuit for a while now, to make a Jacobs ladder, and i thought that it would be perfect for making the arc.

I have read that many people use neon sign transformers, but i was hoping that i wouldnt be forced to buy one of those, and the ignition coil would be sufficient?

Thanks in advance. :)

violet sin - 19-10-2015 at 03:39

for the sake of reading with your bit of free time, take a look at oil burner ignition transformers. I like mine. but I haven't tried running it for hours on end. I have read a few places where you can submerge them in oil to facilitate better cooling. I do know that with 2 platinum tips on the electrodes, I was able to fill a mason jar with orange haze quickly. noticeably strong rusty color in 30-45 seconds. though I have never revisited the issue. workspace is in my basement, so no more of that making toxic gas. have fun play safe, and read the existing thread through if you havent already

hissingnoise - 19-10-2015 at 04:28

Quote:
I like mine. but I haven't tried running it for hours on end.

It will burn out if left running!

Thermal cut-out required . . .


WGTR - 19-10-2015 at 05:59

I've posted some of my frustrations here, and other places in that thread.

My employer took an interest in what I was working on, i.e., I'm now getting paid to develop it, so I won't be posting more updates. However, I think my previous posts will provide some helpful information.

hissingnoise - 19-10-2015 at 07:37

Quote:
I'm now getting paid to develop it.

Now that's interesting ─ tell us more?


Bert - 19-10-2015 at 09:23

There was a long ago link to a Russian process designed to use off peak electricity in electric arc generation to make NOX, combine that with cellulose in unprocessed farm chaff/straw/cellulosic byproducts and have an essentially free solid Nitrogen fertilizer... It's on here somewhere.

WGTR - 19-10-2015 at 10:56

My hobbies and work tend to overlap. The majority of my projects are duplications of earlier research, much of it 100+ years old. When they become more than that I need to get prior approval before posting them (which I sometimes can). Sometimes things go the other way, and my little projects turn into actual work. If it wasn't for my employer's generosity, I wouldn't have the resources to contribute much in any case.

Ammonia oxidation is more economical on the industrial scale than the BE process. On the lab scale, however, the economics are reversed. There are several commercial areas where a reliable supply of on-demand nitric acid might be useful. We're currently aiming towards a small unit that will operate > 1 year without requiring significant maintenance. Of course, the efficiency will have to rival the original industrial process, and be fairly safe to operate indoors.

I'm all ears for ideas regarding potentially viable markets. The wider the market, the more likely this will become available, and that would probably benefit SM members in some way.

Thanks, Bert. I'll see if I can find the patent that you're referring to. It doesn't ring a bell off the top of my head.

Fulmen - 19-10-2015 at 11:35

WGTR: I have a hard-on right now :D

Aurium - 19-10-2015 at 12:33

Yea WGTR what do work on?
Even an engineer wouldn't have that freedom of interest at his job. :o

About the reactor, well there have been many many of these Birkeland–Eyde process reactors based on arcs, maybe we could try something different.
I'm thinking about experiment with lower or higher chamber pressures, see if that improves efficiency,
or doing something totally different which is building a reactor that works based on corona discharge, or (another different thing), a Dielectric barrier discharge.

I know I know the main theory about these arc reactors is that it's the arc's extreme temperatures doing the chemistry happen, but them again, any one of the methods I mention also create allot of free nitrogen ions, and at much higher efficiency.

Read on EHD thrusters or lifters.

antimon - 20-10-2015 at 00:49

I was thinking about trying to apply pressure to see what happens. That would be interesting. But i guess that must have been done before.

WGTR: I tried to click the link, but i couldnt go any further. Its not a safe website it say. :(

Anyway, it is interesting work you do. I wish you best luck with it, and im looking forward to seeing your process. :)

I was thinking about this ignition coil, and if that would work. If it is too weak or too strong power.

I have read about using the oil ignition coil, but right now i only have the VW Golf ignition coil and i want to check it out to see what its good for.

I want to do this right, so it will be as efficient as possible, so i was thinking about the driver circuit. Are the 555 circuit good enough to control the coil, or should i maybe look at another circuit design?

Thanks for all the replies. :)

antimon - 20-10-2015 at 23:38

Yesterday i read in some patent that the electric arc that was used in that reactor was flattened out with the help of a electromagnet.
How do you do this?

WGTR - 21-10-2015 at 16:05

It is a fun job :D

Arc deflection is related to arc current and magnetic field strength. If it doesn't deflect, then the current isn't high enough for long enough time, with a strong enough magnetic field.

You can follow the links safely. If you look at the links, they point to the HTTPS version of Sciencemadness. I get this message all the time. Polverone has explained it here:

http://www.sciencemadness.org/talk/viewthread.php?tid=25296

antimon - 22-10-2015 at 05:10

WGTR: im going to check it out. I'll send you a pm if thats ok?


Magpie - 22-10-2015 at 13:54

Have you reviewed this thread?
http://www.sciencemadness.org/talk/viewthread.php?tid=1518&a...

I commend those trying to develop an efficient NO generator. But I think the real rub is going to be absorbing NO2 in water effectively.

[Edited on 22-10-2015 by Magpie]

PHILOU Zrealone - 22-10-2015 at 14:08

Quote: Originally posted by Magpie  
Have you reviewed this thread?
http://www.sciencemadness.org/talk/viewthread.php?tid=1518&a...

I commend those trying to develop an efficient NO generator. But I think the real rub is going to be absorbing NO2 in water effectively.

[Edited on 22-10-2015 by Magpie]

Maybe NaOH could help a bit... making a mix of Na nitrate and nitrite?

NO2 + H2O --> HONO + HONO2
3 NO2 + H2O --> 2 HONO2 + NO

Alternatively NH3 would make only NH4NO3 since NH4NO2 decompose to N2 and H2O.

Polverone - 22-10-2015 at 14:59

Quote: Originally posted by WGTR  
My hobbies and work tend to overlap. The majority of my projects are duplications of earlier research, much of it 100+ years old. When they become more than that I need to get prior approval before posting them (which I sometimes can). Sometimes things go the other way, and my little projects turn into actual work. If it wasn't for my employer's generosity, I wouldn't have the resources to contribute much in any case.

Ammonia oxidation is more economical on the industrial scale than the BE process. On the lab scale, however, the economics are reversed. There are several commercial areas where a reliable supply of on-demand nitric acid might be useful. We're currently aiming towards a small unit that will operate > 1 year without requiring significant maintenance. Of course, the efficiency will have to rival the original industrial process, and be fairly safe to operate indoors.

I'm all ears for ideas regarding potentially viable markets. The wider the market, the more likely this will become available, and that would probably benefit SM members in some way.


On-site production of fixed nitrogen for agriculture, maybe? I like the <a href="http://www.sundropfarms.com/facilities/">Sundrop Farms</a> greenhouse concept, and there are likely times when they have surplus PV electricity. If you could combine e.g. limestone with surplus electricity and water to make a nitrate solution, that would be a good use for otherwise-wasted electricity plus make the facility even more self sufficient.

There might also be opportunities at a larger scale doing the same with off-grid farms that have solar or wind power. Most of the world's fixed nitrogen demand goes toward farming, and intermittent renewables that sometimes produce surpluses are becoming more common, so if you can hitch your reactor to those trends I think you'll have plenty of room for growth.

WGTR - 22-10-2015 at 21:41

Quote: Originally posted by antimon  
WGTR: im going to check it out. I'll send you a pm if thats ok?
Sure!
Quote: Originally posted by Magpie  
Have you reviewed this thread?
http://www.sciencemadness.org/talk/viewthread.php?tid=1518&a...

I commend those trying to develop an efficient NO generator. But I think the real rub is going to be absorbing NO2 in water effectively.
Yes, I've researched that thread thoroughly. I also obtained a copy of Webb's "The Absorption of Nitrous Gases". It's a useful book and enjoyable to read.

The absorption problem can be a difficult one, but there are viable options for attacking it.

Quote: Originally posted by PHILOU Zrealone  

Maybe NaOH could help a bit... making a mix of Na nitrate and nitrite?

NO2 + H2O --> HONO + HONO2
3 NO2 + H2O --> 2 HONO2 + NO

Alternatively NH3 would make only NH4NO3 since NH4NO2 decompose to N2 and H2O.
I've given the idea some thought. Right now, though, we're trying to fix nitrogen from air, so adding ammonia feels like "cheating" in a way. We'll probably use an alkaline scrubber to capture what doesn't get properly absorbed, but otherwise we're intending to just make the acid. For hydroponic applications, I think it would be best to decouple the nitrate additions from any cations such as calcium, ammonium, etc (which can be added separately if needed), so having the acid itself would be more useful.

Quote: Originally posted by Polverone  
On-site production of fixed nitrogen for agriculture, maybe? I like the <a href="http://www.sundropfarms.com/facilities/">Sundrop Farms</a> greenhouse concept, and there are likely times when they have surplus PV electricity. If you could combine e.g. limestone with surplus electricity and water to make a nitrate solution, that would be a good use for otherwise-wasted electricity plus make the facility even more self sufficient.

There might also be opportunities at a larger scale doing the same with off-grid farms that have solar or wind power. Most of the world's fixed nitrogen demand goes toward farming, and intermittent renewables that sometimes produce surpluses are becoming more common, so if you can hitch your reactor to those trends I think you'll have plenty of room for growth.
We were talking about how useful something like this might be for a farm out in the middle of nowhere, with limited access to resources. I wasn't aware of an agricultural operation that was actually operating this way, though. I really appreciate your input; it turned on a few light bulbs for me. I'm willing to bet that they don't get their nitrates from seawater.

Fulmen - 23-10-2015 at 04:02

I agree, a straight acid generator will be the most versatile, any neutralization can be done in a separate step allowing virtually any nitrate to be manufactured with the same setup.

The biggest issue as I see it is absorption and the ability to reuse the NO produced in that step. With straight air you're pretty much doomed to eject that NO as you have a surplus of N2, a zeolite oxygen generator should allow feeding it with a perfect gas blend allowing greater efficiency.

hissingnoise - 23-10-2015 at 06:23

Quote:
The absorption problem can be a difficult one, but there are viable options for attacking it.

An idea mentioned here a few times ─ that of combining the effluent of an ozone generator with that of a BE generator to oxidise half of the formed NO2 in the stream to form the anhydride would certainly solve the absorption problem!


Magpie - 23-10-2015 at 16:40

Quote: Originally posted by Fulmen  

The biggest issue as I see it is absorption and the ability to reuse the NO produced in that step. With straight air you're pretty much doomed to eject that NO as you have a surplus of N2, a zeolite oxygen generator should allow feeding it with a perfect gas blend allowing greater efficiency.


If you could separate the NO from the N2 then you could recycle it. But that likely is a tall order also.

Sulaiman - 24-10-2015 at 01:16

Since a hot electric arc is used to produce NO
could a high voltage corona discharge be used, either before or after the arc
to generate ozone which would rapidly convert NO to NO2 ?
OR (total speculation here, never tried)
could the equipment be run at low enough pressure to use a plasma discharge which might produce ozone and NO2 simultaneously?

[Edited on 24-10-2015 by Sulaiman]

Fulmen - 24-10-2015 at 01:33

No, separating out the NO doesn't sound feasible to me either. Could it be utilized for something else fun?

hissingnoise - 24-10-2015 at 04:53

Quote:
Since a hot electric arc is used to produce NO
could a high voltage corona discharge be used, either before or after the arc
to generate ozone which would rapidly convert NO to NO2 ?
OR (total speculation here, never tried)
could the equipment be run at low enough pressure to use a plasma discharge which might produce ozone and NO2 simultaneously?

The NO formed is readily oxidised by free oxygen on cooling but ozone will oxidise NO2.
2NO2 + O ─> N2O5

Being the anhydride of HNO3, N2O5 reacts readily with water, forming HNO3 with no off-gassing!

Airfed ozonisers produce NO2 in addition to O3 if the air contains moisture but amounts are largely uncontrollable . . . ?


Fulmen - 24-10-2015 at 04:59

Ozone seems like a viable idea, either by passing the cooled output from the arc reactor (does have a nice ring to it, eh) through an ozone generator or possibly by absorbing it into ozonated water?

Hissingnoise: While NO is oxidized by air to NO2 the reaction is slow, especially in low concentrations:
https://en.wikipedia.org/wiki/NOx#Formation_and_reactions

I would expect ozone to primarily increase this reaction, although some anhydride could be formed as well. Either way, yields should improve.

The BE-process is said to produce up to 4% NO, ozone generators should be able to produce ozone in similar concentrations. So it seems like it's possible to produce enough ozone for this to be possible.

[Edited on 24-10-15 by Fulmen]

hissingnoise - 24-10-2015 at 06:10

Quote:
Hissingnoise: While NO is oxidized by air to NO2 the reaction is slow, especially in low concentrations.

Indeed yes, the process requires a large chamber for oxidation to occur prior to absorption . . .


Fulmen - 24-10-2015 at 07:27

And even then there will probably be significant losses since you're starting out with perhaps 3-40000ppm at best. Of course a relatively large volume shouldn't be too hard to achieve considering the size of a home setup, but ozone (perhaps in a secondary stage) has the potential to increase yields and limit the need for exhaust gas scrubbers. And if one follows WGTRs design with HV ignition of a LV arc you already have the HV needed to generate ozone.


hissingnoise - 24-10-2015 at 08:03

And if correctly configured, it would eliminate the need for absorption towers altogether!


Fulmen - 24-10-2015 at 12:26

It does seem like a realistic approach, but we need a lot more data on the N2O4/O3-reaction. This seems like a good starting point:
http://pubs.acs.org/doi/abs/10.1021/bk-1996-0623.ch008

Fulmen - 25-10-2015 at 06:44

Is there any reason to suspect that passing NO/NO2 through an ozone generator could destroy any of the nitric oxides? Industrially they seem to produce it separately, but that would likely be for process control. Assuming all NO is oxidized to N2O5 you would get a theoretical yield of 0,88g HNO3 per gram O3, the numbers should be far better if the initial NO is allowed to react with air. Running the output from the arc reactor through an initial absorption column (producing weak HNO3), then ozonating the remainder before absorbing it in concentrated acid should produce a quite effective setup for FNA.

WGTR - 25-10-2015 at 17:31

I've been following the posts in this thread with interest recently, but things have been busy during the past several days. I'm not yet able to interject a post that will do complete justice to the contributions from the posters here.

I agree that ozone seems to be an attractive choice to promote full absorption of nitric gasses. However, I think it would have to be generated inline to the NO2 stream, not added separately. This avoids the further dilution of the NO2 gas stream. On the other hand, NO decomposes O3 catalytically in the presence of oxygen radicals.

ozone.png - 102kB
Fundamentals of Atmospheric Modeling, Mark Z. Jacobson

This would seem to suggest that perhaps NO needs to be kept out of the O3 generator.

In Webb's book, he stated that ozone generally affects a change to N2O5 with only about 33% efficiency.

I realize that there is a lot of interest in making fuming nitric acid, but I think that any system we make will be producing diluted streams of acid. There are several reasons for this. For one, 20% acid can be attained from very dilute acid simply by boiling it down in a beaker. I'm working from memory on this one, but I believe that after boiling out 1/2 of the acid (on a HNO3 basis) from a dilute solution, the residue is already constant boiling 68% acid. In any case, it's not hard to concentrate it. Fuming nitric can be made the usual way, with concentrated sulfuric acid, if someone wants to go through the effort. What we don't want to do is offer a commercial product that someone can directly use to make explosives. That would be a bad idea, and bad press, in my estimation. The current EU regulations that limit commercial nitric acid to 3% is not so much a problem in itself. The main problem is that the cost for the 3% acid will likely be very uneconomical, like buying 3% H2O2 at the grocery store is. What would be interesting to know, is if the 3% acid is widely available in the EU now, and what its cost is. Making your own 3% acid would save money over time, if significant quantities were being used. Also, N2O5 is somewhat unstable according to Webb, and extra precautions would need to be taken if this was part of the process.

I'd like to scan Webb's book for the library here, if I can get the time soon. We already have a copy here, but several pages are illegible, and a significant number of important charts and illustrations are missing.

Anyway, enjoy!


Attachment: Oxidation_of_Nitric_Oxide_in_Two-Stage_Chemical_Scrubbers_Using_DC_Corona_Discharge.pdf (4.7MB)
This file has been downloaded 489 times

[Edited on 10-26-2015 by WGTR]

Fulmen - 26-10-2015 at 02:24

Wow, haven't had the time to read the entire JHM-article, but it seems to confirm our hypothesis.

For a commerical setup I agree that fuming acid isn't that interesting, and it would probably only be achievable with significant loss of yield. But for a home setup I think it's at least worth exploring.

antimon - 30-10-2015 at 14:08

Hi, i have read the threads here on the forum about this reactor, and i must say that i have become a lot clearer about how i am going to construct it.

I have planned to use an ignition coil all this time, but after researching it i decided togo with a NST. I ordered a 6kV neon sign transformer from ebay yesterday. So i hope that will make things easier for my project.

I would like to see whats going on so i am going to use a large glass jar for the arc chamber. Now i am just waiting for some glass drill bits that i ordered earlier this week.

And that´s what i am wondering about. I am a little bit unsure how many holes i will need to drill in the jar, so i wanted to ask you.
1. One inlet for the pump, right?
2. And then an outlet so that the NO can get out of there to the bubblers.

Are there any more?

Lastly, i am almost 100% sure that i am going with a stationary arc, instead of a ladder. So i am going to drill a hole on each side of the jar for the electrodes to sit in.

I had a whole bunch of questions but i can´t come to think of any right now. I´ll be back later this weekend.

Thanks for all your posts. I appreciate it.

antimon - 30-10-2015 at 15:13

Ps. Does anyone here have experience with electric arcs, and magnetism?

Aurium - 30-10-2015 at 15:44

You need the high voltage to trigger an arc discharge to jump across the terminals, once the initial arc is formed, it acts as a very very low resistor, very conductive, between the terminals.
This shorting of the terminals will allow a high current to flow, decreasing voltage to almost nothing and overloading the power supply, reducing power transfer and efficiency, allot.

If the goal is to create the largest, hotter arcs, perhaps we can try using a power supply with lower impedance, like a microwave oven transformer (MOT) or a welding power supply.

These sources don't have enough voltage to strike an arc, but when arc is formed, the higher currents delivered cause huge huge arcs.
To get an arc started one could touch the terminals together or superimpose a small HV power supply, just to trigger the arc.

This is exactly how many guys make homemade Arc Furnaces. 2 MOTs recoiled to give some 48V at 1Shitton of amps can keep a long arc.
Even a regular MOT at 2200V can make 30cm arcs.

WGTR is following this technique and I think he's right on the money here.
I'v been reading your older posts about the electrodes corroding away.
Have you tried using graphite rods from batteries?

WGTR - 30-10-2015 at 18:13

antimon

Link to the part that you ordered?

Glass should be drilled while submerged under water. It's less likely to crack this way. Still, it will take considerable patience.

The number of holes sounds about right.

Compressed air is one option for an air supply. Also, a weighted trash bag full of air can be used, and this is similar to how old pipe organs used weighted bellows to regulate air pressure.

The last reactor that I posted on here was built with clay. If my memory is correct, I used A.P. Green fireclay, grog, and about 10% OM-4 ball clay for added plasticity. This was bisque fired at 1000C for a couple of hours (Bisque, not biscuit. What, do I look like Martha Stewart?!?). This firing schedule wasn't intended for vitrification, only to achieve suitable strength for handling.

It's probably better to use a strong rare-earth magnet to try deflecting the arc first, until you learn how this works. Don't hold the magnet close to the arc with your hands!!! Bzzzt!! Owww!! Owww!!!

antimon - 30-10-2015 at 18:44

WGTR : The site is in swedish, so i will try to find one on eBay.

I ordered a Dremel 3000 and two different drill bits.

Here it is.
http://m.ebay.com/itm/Dremel-662-Glass-Drilling-Diamond-Dril...

Would you use a stationary arc, or a ladder? It seems like its easier to flatten it out if its stationary.

Thanks for the tip. I will use a stick or something. :)

Aurium : I dont know if the strongest hottest arc is what you should aim for.
I am in the process of making a Jacobs ladder with one mot. But i am thinking of using one more in series.


Sulaiman - 30-10-2015 at 22:26

I imagine that using an NST will make the electrodes fairly hot
and using an MOT will make them VERY hot
possibly hot enough to soften or even melt glass
so a pottery vessel and/or heatsinking for the electrodes are required I suspect.

Fulmen - 31-10-2015 at 03:31

TIG electrodes should be the obvious choice, they're not expensive and readily available.

For the PSU I agree that WTGR probably has the simplest and best method. And as it happens I do have a complete ignition coil & driver lying, so I just might have to test this one of these days. I also have an 8A variac that should be suitable for supplying power at varying voltages.

antimon - 5-11-2015 at 07:46

I recieved my 6 kV NST today, and when i opened the box and i checked the output and i saw that it said: 3.2kV-E-3.2kV 24mA 30 kHz.
Does this mean i have been cheated, or do the leads put out 3.2 kV each? Probably not i suppose.

But on the pro side it seems to have a knob that i hope adjusts the voltage, but im not sure.

Anyway, do you think this one is sufficient for a small test setup? just until i get a stronger one, like 10 or 12kV ?

I got the drill bits, and i drilled two 6.2 mm holes in the bottom of a large glass jar. I am thinking about doing two more for the electrodes, but if i can come up with a better way i will skip that.

If the jar doesnt hold up to the temperature i will use terracotta flower pots.

I am going to get tungsten welding sticks.

If you dont count the bubblers, are there something more that i need to complete the setup?

[Edited on 6-11-2015 by antimon]