Nitric Acid Experiment Pictures

[megalomania]

I have taken some pictures of my most recent experimental setup to prepare nitric acid. These pictures show the apparatus that I set up including an ammonia generator, catalyst chamber, and a bubbler. Unfortunately the experiments were plagued with difficulty exposing some weaknesses with my design. Ultimately I was unable to produce nitric acid, or not enough to detect. No matter, I have redesigned the entire apparatus to correct for the problems. I will post the new plans some time soon. I will build it soon after as I already have the parts I need.

This first picture shows the entire setup.
<img src="http://www.roguesci.org/megalomania/experiments/web1.jpg" alt="" />

This second image shows a close-up of the ammonia generator. Here I use a 500-mL round bottom flask with standard taper connections to hold my ammonia. I use here ordinary ammonium hydroxide straight from the store. The flask is heated by a Thermowell (hotplate). The sep funnel acts as an addition funnel. The condenser helps return some of the water vapor that comes with the ammonia. The air compressor to the right supplies the air through the hose that goes straight down into the flask. This supplies both an excess of air, and increases the velocity of the vapor flow. As it turns out the air compressor produced way too much airflow, even at its lowest setting. The air kept frothing large amounts of water into the catalyst chamber.
<img src="http://www.roguesci.org/megalomania/experiments/web2.jpg" alt="" />

Here we see the catalyst chamber itself. I have employed 3 lengths of steel tubing connected together. The center tube contains the catalyst, and is heated by the torch. The other 2 tubes are supposed to be heat sinks, but this did not work out well. I wrapped them with cold towels as a temporary measure, but they still run hot. Most of the new design centers on creating a better way to keep the inlet and outlet cool before it contacts the plastic tubing.
<img src="http://www.roguesci.org/megalomania/experiments/web3.jpg" alt="" />

Here is a close-up of the bubbler. This particular setup has the outlet tubing connected to a glass tube that extends to the bottom of a glass cylinder. This setup is unacceptable for actual nitric acid production as a third of the product would be lost. As it is here, it is easy to see.
<img src="http://www.roguesci.org/megalomania/experiments/web4.jpg" alt="" />

This picture uses coloring to demonstrate the intended reaction and makes the liquid portions easier to see. The blue liquid in the flask and addition funnel is ammonia, stating from the generator. The red liquid in the cylinder is the nitric acid.
<img src="http://www.roguesci.org/megalomania/experiments/web5.jpg" alt="" />

[megalomania]

Here I am modeling the setup. These pictures are like the above. Check out those legs.
<img src="http://www.roguesci.org/megalomania/experiments/web6.jpg" alt="" />
<img src="http://www.roguesci.org/megalomania/experiments/web7.jpg" alt="" />
<img src="http://www.roguesci.org/megalomania/experiments/web8.jpg" alt="" />
<img src="http://www.roguesci.org/megalomania/experiments/web9.jpg" alt="" />
<img src="http://www.roguesci.org/megalomania/experiments/web10.jpg" alt="" />

[nbk2000]

Nice gams there, Mr. Wizard!

:p

But seriously, you need a couple of U bends on the ends of your reactor. These are immersed in water, with a constant flow of cold water being supplied by a hose. The overflow goes to the drain. This way, your hoses will never get hot enough to melt.

Using a spiral coil, instead of a U, will greatly cool down the nitric acid vapor as well.

<img src="http://server3001.freeyellow.com/nbk2000/nitric.gif" alt="" />

And, if I'm not mistaken, isn't vanadium oxide also useful as a catalyst? If so, then you can get that by the pound at ceramic suppliers.

<small>[ June 10, 2002, 10:59 AM: Message edited by: nbk2000 ]</small>

[Alchemist]

Hello Mega,

Very nice. What are you using for the catalyst?

P.S., I have sent you some e-mails, but they came back! Have you changed adddress? Email me when you have time.

[mr.evil]

Nice set up you got there mega! do you have more pictures of your lab?

[stanfield]

I don't understand something :
it's so easy to distill nitrate+sulfuric or low concentrated nitric acid... so, why do you bug yourself by setting up an "home-industrial" plant ? I would like to know how much nitric acid do you get at the end of your apparatus, and, ofcourse, what's its concentration ?

see ya !

[mr.evil]

You can see that the HNO3 is orange, so it must contain lots of NOX, is there any way to prevent this? like bubble it under vacuum?
where do you get such nice glassware? There are many Glassware company's in my city, but none of them sells that tiny little pieces of glassware and industrial stuff...

[Anthony]

The orange liquid is just coloured water to show what the setup would look like if it was working.

If the compressor is giving too much flow, a simple hose clamp around the about tube should enable you to regulate it a bit. A valve would be better but a hose clip is a few second job and costs a few cents.

[megalomania]

Here is a pair of pics of selected excerpts of my notes detailing my next design. I intend to user a copper preheating coil wrapped around the catalyst chamber with both a pre- and post-cooling reservoir. The first picture shows an overview of this design, and the second shows a more detailed close-up of the catalyst chamber.
<img src="http://www.roguesci.org/megalomania/experiments/design1.jpg" alt="" />
<img src="http://www.roguesci.org/megalomania/experiments/design2.jpg" alt="" />

Often my email box gets filled to the max. Because Hotmail has become a cheap bastard about this, they bounce all emails back when it is full. Try sending it again, eventually I will clean the thing out. I am preparing to move to a new account for private correspondence.

The reason behind using this method is one of economy. Not all people have access to nitrate fertilizer, but everyone has access to ammonium hydroxide. The efficiency of this process makes it far cheaper as well. Furthurmore, this is the most suitable method for making 120% fuming acid, or ever 100% acid. You can only do this from nitric oxide fumes, which distillation does not give. Also, this setup does not require exotic glassware. I may be using exotic glassware here, but that's just because I have it. My final design will be set up in such a way that all of the equipment, chemicals, and connectors will be from everyday hardware stores and grocery stores.

<small>[ June 11, 2002, 02:46 AM: Message edited by: megalomania ]</small>

[10fingers]

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<small>[ June 12, 2002, 08:51 PM: Message edited by: 10fingers ]</small>

[DBSP]

It looks very nice, only I don't excactly understand the process. If anyone has any texts or chematics on this I'd really like to see them. I'm especially interested in seing some simplifyed drawing of the setup, like the one posted but with the substances put out as well. And what yields can you expect from this method. To me this method is very interesting since I only have limited acces to sulfuric acid.

Sorry if its a lot of questions at once.

<small>[ June 11, 2002, 06:20 AM: Message edited by: DBSP ]</small>

[mr.evil]

yeah i like to see some documents of the above method... :)
(i have lots of H2SO4, and i can get it very cheap but anyway)

[Flake2m]

Meglomania, could you please post a chemical equation on how nitric acid is produced from ammonia and air. I am a chemistry student so this would help me to understand how this proccess works.

My other problem concerning this production is:
Most store bought ammonia products contain about 1 mol per litre, they also contain impurities in them (soap etc) that may interfere with the production of ammonia.
Where would I be able to purchase a bottle of concentrated ammonia, something in region of over 5 moles per litre?

[Microtek]

The ammonia that is sold in the stores around here ( Denmark ) is at least 20% and more often 25% NH4OH which would make it almost six and a bit more than seven mol per litre, respectively.

[mr.evil]

i can buy very easily 25l cans of 15% Ammonia, and in stores 5-10% Ammonia. I have also some 25% Technical Ammonia(5L) For the europeans here, in Belgium you can buy lots(!) at the drug store, they even sell Hg Salts!! <img border="0" title="" alt="[Eek!]" src="eek.gif" />

But anyway, if you have some common 5-10% Household ammonia, i suggest you destillate it...
(on the link below you can see a picture of the NH4OH purification...and some other pics) :)

<a href="http://www.geocities.com/tshadowpp/temporarypreviewfile.html?1023798912390" target="_blank">http://www.geocities.com/tshadowpp/temporarypreviewfile.html?1023798912390</a>

[10fingers]

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<small>[ June 12, 2002, 08:50 PM: Message edited by: 10fingers ]</small>

[DBSP]

I belive that you can buy conc ammonia in sweden too, about 25%.
What catalyst is best to use, both in the perspective of acuisition and performace?

[Alchemist]

Hello All,

The Formation Of Nitric Acid From Ammonia

Nitric acid (HNO3) is made from ammonia (NH3).

The reaction happens in three stages:

1. Ammonia and oxygen from the air are reacted together to make
nitrogen monoxide and water.

They are heated to 300 0C and passed over a catalyst of platinum (other catalyst's
have been used).
(A catalyst speeds up a chemical reaction without itself being
changed).

The reaction makes its own heat (exothermic) and is cooled down by
using more air than is needed to react with the ammonia.

4NH3 + 5O2 --------&gt; 4 NO + 6 H2O

ammonia + oxygen -----------&gt; nitrogen monoxide + water


2. The nitrogen monoxide is reacted with more oxygen from the air to
make nitrogen dioxide which is a brown poisonous gas.


2 NO + O2----------&gt; 2NO2

nitrogen monoxide + oxygen ----------&gt;nitrogen dioxide



3. The nitrogen dioxide is dissolved in water in the presence of air to
make nitric acid.


4NO2 + O2 + 2 H2O----------&gt; 4HNO3

nitrogen dioxide + oxygen + water---------&gt; nitric acid

<small>[ June 11, 2002, 10:39 AM: Message edited by: Alchemist ]</small>

[rikkitikkitavi]

I think the major obstacle is that the rxn
2NO + O2 is a very slow one at atmospheric pressures and low conc of
NO, &lt; 10 %

Kinetics doesnt work in our favour :(

Found the following data in a text book.
Time of rxn for 50 % of original NO to react.
@ 60 C 760 mm Hg

Starting concentration (% volume)

O2 NO time (s)
6,5 5 25
6,5 3 40
6,5 2 57
6,5 1 112
6,5 0,5 225
6,5 0,1 1100
6,5 0,05 2200

10 2 37
6,5 2 57
4 2 98
(damn it , who do I get a nice table? Spaces just get squirked together)

reaction speed r ~ [O2] * [NO] ^2

(solving the differential equation

d[NO]/dt = - [O2] *[NO]^2 gives a expression of how NO varies with time

The reason why they build BIG houses covered with lead sheets in the lead chamber process was just for the reason of giving the NO=&gt; NO2 reaction enough time to take place.

So instead of leading the hot gases directly to a absorbtion vessel we have to give the NO time the reaction come through.

And chemical reaction kinetcis learns that letting the gases enter a large chamber
(where they would be dilutied, both through large volume and rxn) between the catalytic cumbuster(sorry couldnt help it:) and the absorbtion vessel is less favourable than simply using a looong hose(or tubing ). In the latter case the rxn is the only factor lowering NO-conc and thus reaction time.

How long? Experiments is probably best way to find out since there is many variables.

/rickard

<small>[ June 11, 2002, 01:52 PM: Message edited by: rikkitikkitavi ]</small>

[vulture]

10fingers, the catalyst from an automitive is designed to convert NOx into N2 and [O], if there was any NO produced in your process, it would have immediatly been converted to N2 and [O].

[PYRO500]

You know, that flask with the bright blue vapor/liquid, it looks alot like an XTC lab I have been to where the were producing freebase :) .

[Alchemist]

Hello all,

This is a very small scale demenstration of the process only!

Also, oxides of iron with traces of oxides of other common elements have been used!

Catalytic Oxidation of Ammonia

Equipment

250-mL Erlenmyer flask, rubber stopper for flask, barbecue lighter, rod to support wire across the top of
the flask, coiled platinum wire. The coil should be approximately 7 mm in diameter and loose enough that
the adjacent coils so not touch.

Reagents

25-75 mL of concentrated aqueous ammonia solution.

Presentation

1.Pour the ammonia solution into the flask and stopper it.
2.Attach wire to its support.
3.Adjust the length so that the end of the platinum is 1-3 cm above the surface of the ammonia
solution.
4.Unstopper the flask.
5.Heat the end of the platinum wire until it begins to glow red.
6.Quickly, put the wire down into the flask.
7.The wire will glow brightly.
8.The wire may be removed from the flask and it will cease to glow.
9.If the wire is returned to the flask before it gets too cool, it will again glow brightly. This may be
repeated many times.

Hazards

Concentrated aqueous ammonia can cause burns and is irritating to the skin, eyes, and respiratory tract.
Nitrogen dioxide is an extremely toxic gas. It is irritating to the respiratory tract.

Discussion

Ammonia is catalytically oxidized at the platinum surface according to the following reaction.

5 NH3 (g) + 5 O 2 (g) 4 NO (g) + 6 H2O (g)

The reaction is exothermic and as written releases 920 kJ of energy. A second reaction proceeds
automatically from the first reaction.

2 NO (g) + O 2 (g) 2 NO2 (g)

The second reaction is also exothermic and as written releases 112 kJ of energy. These two reactions
taken together make up two thirds of the Ostwald process for the synthesis of nitric acid. If the NO2 (g)
were put into contact with liquid water, nitric acid and NO (g) would be produced. The initial heating of the
wire with the lighter provides the actvation energy for the reaction. Once the reaction begins, the released
energy will provide more than enough activation energy for subsequent reactions to occur. An interesting
variation of this demonstration is to substitute a thin copper wire, approximately 0.2 mm in diameter for the
platimun wire (2). The heat from the reaction is sufficient to melt the copper wire. The molten copper will
spatter and make a spectacular effect. Additionally, some of the copper will oxidize and turn the ammonia
solution blue by forming a complex ion between the Cu 2+ ion and the ammonia [Cu(NH 3) 4] 2+. This
variation does not work as consistently well as the platinum version does.

[megalomania]

The technical details I am keeping to myself because there is a lot to write. I have also concluded that using the straight ammonia is probably not good. The ammonia in the US is 2-3% on average, and if you are lucky you may find a 5%. I have used the $0.99 a gallon 3% variety thus far. I have a few more experiments to try with this type of ammonia because anything more concentrated requires more materials, and more expense.

The key to the reaction is the residence time of the NH3 on the catalyst. The ideal time is 0.04 s and the ideal amount of O2 is a sixfold excess. If the residence time is to long you will decompose the ammonia into nitrogen and water, if it is too short you will get ammonia with your nitric acid and end up with ammonium nitrate in your product. The choice of catalyst will also affect residence time. Copper, which is what I am starting with because it is the cheapest, is more likely to decompose ammonia if the residence time is too long. Platinum, the catalyst in automotive catalytic converters, is the best, but it is also very expensive and difficult for many people to obtain. Notice the catalytic converters are quite large (long). This forces a lengthy residence time, resulting in mostly harmless products. I have a cross section of a cat converter that I have not experimented on yet. When I use it, I will use a cm or less.

I will experiment with a variety of catalysts. The one good thing about all this, even with an expensive catalyst like platinum you lose very little over long periods of time. In a low-pressure system like mine, you may not lose any at all. My copper sponge is straight from the grocery store, dirt cheap, and allows airflow. Platinum from a cat converter is either small spheres (older ones) or a honeycomb mesh, which also allows airflow. Using powder catalysts, and other metals, will require it be attached to a suitable surface to allow a free flowing system. I have ways of doing that, but again, that adds extra expense and materials most people may not have.

Alchemist, your forgot to mention in your equations that 3NO2 + H2O --&gt; 2HNO3 + NO
You will lose 1/3 of all the NO2 produced this way. That is why I mentioned my “bubbler” is unsuitable. Of course I am not concerned with peak efficiency as of yet, just getting the thing to work (one problem at a time please). I have not devised a system, but my ideas range from the simple ‘several bottles in series’ to a complex ‘water mist tower’.

The reaction is indeed very exothermic. Once it gets going you will be able to stop external heating, and regulate the temp by controlling the flow of ammonia and air. I have net developed my experiments to the point that I need constant temperature and pressure/gas flow measurements, but anticipate I will to get the best experimental results. I do not anticipate these things will be needed in the final system; they are just to find optimal conditions. While I am on this topic, does anyone know of any chemical engineering equations to determine the amount of a substance based on pressure, or air speed? Some links to chemical engineering resources would help me. I haven’t found anything yet. I suppose that is because I don’t know what to look for.

The kinetics of the reaction are actually very, very fast. The reaction between NO and O2 is almost instantaneous at STP, or near enough at small quantities as to look like it. In this reaction we are not at room temp, but up to 300-500 degrees, and that will increase the rate considerably. Rikkitikkitavi, does that table take into account the diminishing volume of NO and the increasing volume of NO2? If that is a closed system we would expect to see less and less NO2 being produced over longer and longer periods of time. In my system we have a fairly constant ratio of NO and O2 at the site of the catalyst. The volume of O2 tapers off as more NO2 is formed, and drops after being bubbled into water. When I develop a series of bubblers there will need to be an additional source of air to react with the NO that forms. This new air source will be added after the first water bottle. If you add too much air from the beginning you may push the ammonia through too fast.

I have seen the experiment done with both the platinum wire and copper wire. That is in fact what has inspired me to do my current experiments. My designs are based on earlier experiments along those lines. I know this works; the theory is sound and has been done for almost 90 years now. Knowing that a thing can be done is an important step to actually doing it.

[nbk2000]

Just a note that the thorium coated gauzes used in gas mantle lamps are used as catalytic converters by clandestine drug manufacturers to convert phenylacetic acid to P2P. Perhaps a thorium mantle would be a quick way to get started?

I've also got several yards of a screen material in storage in california that, even after exposure to intense flame and glowing red-hot, remains intact and flexible. It's not metal, but some kind of synthetic fiber. I found it so I don't know what it is.

Brings to mind an idea of using a platinium salt to coat the screen and then exposing it to a reducing flame to convert it to an activated form that adheres to the screening.

A process for making platinium black and sponge can be found in Dicks encyclopedia (might be in "Grandads wonderful book of chemistry" by Kurt Saxon).

Also, I've read the a container filled with totally anhydrous Ammonium Nitrate prills will absorb a large amount of ammonia gas and hold it like acetone does acetylene. In doing so, it reduces the pressure needed to contain it in liquified form to just a few atmospheres, well within the range of a 2 liter soda bottle or fire extinquisher. :D

Pass the NH3 through two condensers, one with cold water, then drierite, then acetone/CO2 slush to liquify it. Then it'll be purely anhydrous and ready for mixing with the AN for storage. Much easier to control a gas cylinder than a boiling flask. And no dilution of the source material either with water vapor.

[10fingers]

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<small>[ June 12, 2002, 08:49 PM: Message edited by: 10fingers ]</small>

[rikkitikkitavi]

mega, first i like to say:

very impressive setup. A very thorough experiment.
now after cleaning my (brown ) nose to your question.

The table I took my data is to interpreted as the reaction time is the time for 50 % of the original NO-amount to react. No NO2 to start with.

Of course the NO and O2 conc decreases as the reaction progresses, and this is taken in account in the table.

Remember that at temperatures &gt; 200 C the back reaction NO2 &gt; NO + O2
also takes place, thus cooling the gases after the converter increases yield.

high pressures favours the production of NO2, but for us it is probably not an option.

mega, your question about equations? can you specify?
I can recommend some books on chemical engineering just goon look up the ISBN...dont have any online links though :(

/rickard

<small>[ June 12, 2002, 04:42 PM: Message edited by: rikkitikkitavi ]</small>

[megalomania]

My question relates to the calculation of the residence time of the ammonia on the catalyst. I want to know how to calculate it with only simple measurements like a pressure gage, and by taking into account the surface area of the catalyst and the length of the tube.

I have no hard data on the reaction of NO to NO2, but I have first hand observation which tells me the reaction is quite fast. Perhaps on the industrial scale they consider it a problem. We have to deal with is the loss of 1/3 of all our produced oxide anyway. By the sheer fact of having a series of bubbling containers, we extend the reaction time considerably. We will likely have mixtures of oxygen and NO kept in solution or in the air above the water for several minutes. By using 4,5, or maybe more depending on how industrious you want to be, water filled containers we can get almost all of the NO to react.

The temperature I quoted is only in the catalyst chamber. That is the site where NO is formed, and since the residence time at that temperature is so short, the backwards reaction is unlikely to happen. That is what should happen anyway; this assumes one can effectively control the residence time.

For furthur information, I suggest reading US patent 858,904 by Wilhelm Ostwald. He is the authority as he invented the process. This patent is geared to the lab scale, and is perhaps the only available technical information not concerned with industrial scale matters. Very few other resources give as many secrets and insights as that patent (not enough though). Reviewing it now I see I misspoke earlier, you need a minimum of a sevenfold excess of oxygen. One may also note his description on using different catalysts:
“… The speed will depend in every special case on the nature, the surface and the distribution of the contact bodies or catalytic agents and must therefore be determined by experiment. The speed is increased until unoxidized ammonia can be tested in the reaction products and the speed is then kept a little below this limit but as near to this limit as it may be practically possible.”
It is this that I am experimenting to find. Obviously right now my choice of a catalyst is less important than consistently delivering proper ratios of ammonia and air, getting the temperature up, and sending it through fast enough to avoid decomposition.
In reconsideration as I read the literature, I suppose it is not important for me to have chemical engineering equations. I thought it may be helpful to calculate the right speed before experimenting, but I doubt I have the means to precisely determine the equation anyway (short of experimentation which would defeat the purpose).

nbk2000, I am unfamiliar with a gas mantle lamp. What exactly is that, and where can I get one?
I have that info from Dick’s and some related from Vogel’s and the Organic Synthesis series. It is not a problem to make these kinds of things, and is in fact an issue in my notes, but not for my experiments as of now. The importance of making your own metal gauze is if and when supplies of other ready made materials dry up. Copper sponge is the cheapest and most readily available material for the vast majority of people. It is used in drug manufacture, so it will probably dry up in 10 years (I am planning for the long haul). You cannot buy a used catalytic converter; it is illegal in the US to do so. Buying a new one may be prohibitively expensive for some people. In my experience I had to pull some teeth to get the sample I have. One can get platinum metal from jewelry or coins, as well as nickel, rhodium, ruthenium, osmium, and palladium to a lesser extent from many sources. The amount of effort and chemicals needed to convert these things to a usable catalyst may be daunting to some people. Not everyone will have this trouble, but many people will, and I want as many people as possible to be able to enjoy the fruit of my labors. That means a lot of work that can side track me. I just want to know what is the easiest to get and cheapest catalyst, for right now, in 2002.

I like that idea of mixing ammonia with ammonium nitrate, that could be very handy (to me). It is somewhat beyond the scope of my experiments right now because CO2/acetone slurries are not for the common man. That is not so far fetched though that many people could not do it. It gives me another option to try should straight ammonium hydroxide prove to be unsuitable. I had a big problem with excess water vapors. I can exactly test for it, but I believe it drives the temperature way down (at least with 3%). I plan to neutralize the ammonium hydroxide from the grocery store with hydrochloric acid from the hardware store to form ammonium chloride, and then decompose that (after obtaining crystals) by adding sodium hydroxide solution (made through electrolysis or bought as lye). I also intend to try using lime as an absorption medium after heating the straight ammonium hydroxide (3%).

The more ‘stuff’ you need, the more this whole things costs, the harder it is to get, and the more questions you have to answer to the corrupt authorities. Still, there are many options and methods to use here, and so we are not limited by any single one. That means if one does not work for you, you can try another way. I operate under the assumption that eventually every chemical will be banned, or pulled from the shelves. That is why I focus on the easy ‘innocent’ stuff, it will be the last to go.

Edit: If anyone can get these to work, there is a website that supposidly has movies of many chemical reactions. Specificially, <a href="http://chemmovies.unl.edu/chemistry/redoxlp/a28.html" target="_blank">Ammonia Oxidation Catalyzed by Platinum</a> and <a href="http://chemmovies.unl.edu/Chemistry/RedoxLP/a20.html" target="_blank">Oxidation of Nitric Oxide by Oxygen</a>
I think this may be a front page to get you to buy their video disk :( Or my media player isn't working. If somebody can view these, tell me. Oh, the master index of many more interesting movies is at <a href="http://chemmovies.unl.edu/chemistry/redoxlp/redox000.html" target="_blank">http://chemmovies.unl.edu/chemistry/redoxlp/redox000.html</a>

<small>[ June 13, 2002, 12:12 AM: Message edited by: megalomania ]</small>

[Alchemist]

Mega, I saw the mov file in full and it is not very good! They turn the lights off after the flow is started and all ya see is the Pt glowing.

Here is some info on another catalyst. Still expensive, but NOT as bad as Platinum.

COBALT OXIDE CATALYST

Cobalt Oxide Catalyst for Ammonia Oxidation reduces Catalyst cost
up to 75%
Nitric Acid or Nitrogen Oxide have been produced basically the same way since the
beginning using Platinum/Rhodium catalyst. Cobalt Oxide Catalyst is used as an
alternative to solve several problems such as the high cost of platinum; the short
operating cycles; and the by-product reaction producing N²O. Cobalt oxide catalyst is
used in nitric acid plants as an alternative to the Platinum-based catalyst. By using
cobalt oxide catalyst, plants have shown increased production at significantly reduced
operating costs.

Cobalt oxide catalyst technology improves operating cycles and increase efficiency
over the platinum catalyst technology.

Benefits of Cobalt Oxide Catalyst in Ammonia Oxidation
The following are a few of the many benefits of using Cobalt Oxide Catalyst Systems:

Higher ammonia conversion efficiencies:
95% + for high pressure plants (90-120 psig)
98% + for low pressure plants (0-25 psig)

No plant shutdowns due to the catalyst
No need to change out the catalyst charges
No more catalyst inventory costs due to strength and longevity of the catalyst
Lower operating temperatures (about 1550 ºF) results in less heat exchanger failures
Reduced maintenance costs since there are no shutdowns to change out catalyst. Also, longer
runs and lower temperatures reduce equipment failures due to thermal cycling
Lower pressure drop in the system reduces steam consumption or increases the production
through the plant
Much less N²O, which is an environmental pollutant

Economics of Plant Conversion using Cobalt Oxide Catalyst
Cobalt Oxide Catalyst Systems offer a simple short term payback of less than one
year on the initial investment and provides significant long term savings by reducing
catalyst operating costs; reducing maintenance cost; longer production runs; and
improved ammonia conversion. These outstanding savings are possible because
Cobalt Catalyst System reduces basic catalyst operating costs from $3-$4 per ton to
$0.50-$0.75 per short ton of nitric acid. Imagine a 350t/d plant saving more than
$400,000 per year in operating expenses alone. Add increased production from the
improved efficiency and reduced maintenance from longer run times and that plant
could see a yearly savings exceeding $500,000.

Some plant evaluations have even shown that they can recover 75% of the
capital conversion costs from the sale of the platinum/rhodium gauze in
inventory.

Mega, I know this is NOT a complete recipe for the catalyst, but it may give you some ideas.

*** SEE U.S. Pat. 3,931,391 ***

<small>[ June 13, 2002, 05:44 PM: Message edited by: Alchemist ]</small>

[nbk2000]

Gas mantle lamps are available at most decent hardware or camping stores. The most frequent name is Coleman. It uses propane as fuel (usually) and costs about $20. But you can buy replacement mantles for $1 for two mantle, so it's quite cheap.

Obviously one wants to keep the process as simple as possible, but that's not always possible because of the need to make ones own materials, adding steps. The drug chemists have the same problem, but are motivated by a huge profit margin that us pyros don't have.

I've got a bunch of movies off that movie site from last year. Including one with the conversion of ammonia to nitric oxide via copper. It's not all that informative though.

[Flake2m]

I did some reading on the ostwald proccess. I found that it generally uses a platinium/rhodium catalyst as you know these catalysts are very expensive. However, I also found that a platinium/rhodium catalyst is used in car mufflers to turn unreacted fuel, carbon monoxide and NOx into water, carbon dioxide and nitrogen.

This would give me an easy source of a decent catalyst - car mufflers. Since pretty much every car has a muffler you could hypothetically steal the mufflers off a car for the catalytic converters they contain. You could also buy some old mufflers at a junkyard for their catalytic converters (but i think they are removed when a car is salvaged).
Ammonia will disolve upto 400 times its own weight in water, or 1 part of water can hold 400 parts ammonia.

Meglomania - your "bubbler" system may be inefficent but it could be made more efficent by increasing the surface of the outlet, that is instead of having one outlet to bubble out the NO2 use a hose (corrosion resistant) along the bottom of the container with about 20 holes in it, this way the NO2 gas diffuses over a much larger area. You could also keep the water moving, by stirring it while it is defusing, this moves the water/nitric acid mix around and helps it to diffuse faster

<small>[ June 14, 2002, 08:48 AM: Message edited by: Flake2m ]</small>

[photonic]

Ehh, the muffler doesn't contain the catalytic converter on a car. At least not as I understand it. They're two completeley separate things.

[Mick]

yes, a car muffler does contain a catalytic convertor.

i don't know whats in them tho, as i have no use for them.

[EventHorizon]

You usually have a catalytic converter and a muffler both. Usually the catalytic converter is first in the exhaust flow, then the mufflers further rearward.

Would be interesting if it would work. Most people get the converter hot, then dump water down it to break-up the honeycomb in there. As far as I know, you should be able to get a "replacement" converter at a junk/salvage yard.

<small>[ June 16, 2002, 09:34 PM: Message edited by: EventHorizon ]</small>

[10fingers]

The catalytic convertor and the muffler are two separate things. The convertor will look somewhat like a muffler but usually smaller. It will be between the muffler and the engine. Some convertors have two different catalysts inside, a platinum one for oxidation of hydrocarbons and a platinum/rhodium for elimination of oxides of nitrogen.
If you have a grinder with an abrasive cut off disc you can easily cut through the housing of the convertor and pull out the catalyst. The catalyst can be cut with a hacksaw into the desired shape.
I have heard there are state or federal laws prohibiting the sale of used catalysts. The probable reason for this is because they don't want people using a possibly defective catalyst on their car. I've gotten a couple of them from the local junkyard though without any questions asked.
Cobalt oxide can be purchased from ceramic suppliers. I have seen a patent for the farm manufacture of nitrogen fertilizer which used a cobalt oxide catalyst for the oxidation of ammonia. Supposedly it worked better at low pressure than a platinum/rhodium.

<small>[ June 21, 2002, 08:08 PM: Message edited by: 10fingers ]</small>

[Ctrl_C]

Just a question: why is it illegal to buy/sell used cats in the US?

[SATANIC]

i dunno about the US, but here in aus, you can get your car taken off the road / fines for not having one. it's all about reducing greenhouse gasses etc, and the cat plays a vital part in that.

a friend took it out, (part of others mods to the car) and got fined, then had to have it replaced. it was under the engine, tho in the exhaust line / system, not in the actual muffler.

[megalomania]

Since they are quite expensive, some unscrupulous mechanic types try to pawn them off as new parts. You have to have one there, but nobody really cares if it works (except the government). They are one of those things that if they don’t work, who would really know?

The catalytic converter has undergone some design changes in the past decade or so. Newer cars have it right after the exhaust manifold, and some have another right before the muffler. Older cars have it before the muffler. Those are easier to service because it just connects to the piping. Sounds like a mechanics con to me, but I guess the ones in the engine compartment are more efficient, even if they do cost more and require more effort (aka $) to get at.

If I had my way I would remove mine completely. They sap some horsepower by restricting exhaust airflow. You can buy high flow catalytic converters (cat backs) to give more horsepower, and when combined with high flow manifolds and exhaust pipe, can really add some power. Of course if you want a non street legal car, you can use a manifold and no cat converter at all. If I ever buy a high flow manifold, I may just do that because there are no exhaust testing requirements where I live. Of course this is a post best kept on the Ford racing bulletin boards… Yes, shopping for a new car has led me down gearhead alley, and now I dream up ways to mod my car along with making chemicals.

[PYRO500]

Ah, the old remove the cat converter trick, most of the cars in our school parking lot have this done to them,(then again there's only 40 something cars max) the students in the welding class make "Test pipes" (among other illegal things) (straight open pipes that replace the cat converter) and they go race their cars on the dirt roads behind their trailers (fucking rednecks) now I can understand why you would want this on either a newer car or a high performance car but all the cars around here are stupid rusted out trucks. I believe there is a heavy fine for tampering with your emission control system. What I have seen most often with people removing their converters is that they forget or ignore their oxygen sensors. in all fuel injected cars the oxygen sensor plays a crutial part in maintaing a perfect air to fuel mix without it your car slowly adjusts till it runs like shit or not at all then I think you have to manually reset the mix or install the sensor and wait for it to adjust.

[NoltaiR]

A spiral tube would be most efficient (as NBK stated in a previous post) in working with the cooling process. However NBK pictures that the U tube--as I call it--or the spiral tube as suggested would be sitting in a beaker of water I believe. I should think that a way to have running water would be more favorable. Or if you were insistent on having standing water in a beaker then possible an addition of NH4NO3 prills would easily keep the temperature down--such as used in instant cold packs.

P.S. In review of Mega's first post in this thread I would like to say the last pic draws the most attention.. and this may come to my mind so quickly because I am a clothing salesman. Anyways I would like to say that you may be starting a new fasion trend with the lab coat and shorts combo.. I'm diggin it! :D

[nbk2000]

"...a couple of U bends on the ends of your reactor. These are immersed in water, with a constant flow of cold water being supplied by a hose. The overflow goes to the drain."

Read my posts more carefully in the future before commenting on them.

Thank you.

[10fingers]

Another problem I ran into when trying to do this is that if theres any unreacted ammonia going into the water with the nitric acid all you're going to be doing is making ammonium nitrate. Some way has to be devised to remove this unreacted ammonia.
I think rikkitikkitavi mentioned this on a similar thread and it's the only simple way I can think of also. It would be to run your NO into a container of water, before it has reacted with any more oxygen to become NO2. The water would absorb the ammonia, I think the NO should pass through unchanged. This would also cool it down so that it can be led into a reaction chamber with more oxygen to change into NO2. This reaction is slow and is better at around 20*C. Then lead the NO2 into water again where it will combine with the water to become HNO3.
Does this sound workable?

[megalomania]

If you do get unreacted ammonia, you would have to adjust the ammonia flow to decrease it a little until you don't get any. One you have tinkered with the system enough that should no longer be a concern. If you let ammonia go through, you will just be wasting it when it could be acid. It is better to eliminate this problem than to compensate for it.

I have a few ideas as to how to produce the nitric acid after NO2 formation. I will most likely set up a series of glass bottles where the NO produced in the reaction can itself be reacted. The first water container would be the only one to absorb the ammonia, if there is any. Only two thirds of all the NO2 gas actually becomes nitric acid, the other third becomes NO, which passes over into the next bottle becoming NO2 along the way. Two thirds of that becomes acid, and so on and so on until you have very little left. During the course of the reaction the first bottle will absorb less and less NO2 as it gets saturated. These bottles will also get hot, leading to even less absorption. One would have to monitor these bottles to swap them out when they hit maximum capacity. If you let the system run too long, you would end up having NO2 gas spew out.
Industrially they use a tall absorption tower. A continual stream of water if sprayed into the top while the gas is forced up from the bottom. The NO rises and reacts along the way slowly diminishing to zero. The downside of this is they only get 60-70% acid. I don’t think such a system would be useful to me.

I have some trouble getting water where I need it without making a huge mess or redesigning my lab space. Anybody can move a garden hose to cool the pipes, then what? I have no place to easily get rid of the water. Even so, it is the best way. I have used water filled containers as coolers before, and in my experience they get real hot real quick. I can’t make enough ice, so cold water is far superior. Besides the static systems require lots of attention I don’t want to give.

Again, I get ahead of myself. I am still concerned with optimizing NO production for now. I will tackle the other problems as I come to them. In my next experiments I am going to try using pure ammonia.

[DBSP]

It's fucking anoying, I had written a long good reply I hit the add reply button and then, :mad: , internet colapses.

Anyway, what I wrote was that if you have a grden hose that enters an eclosed container around the place that needs cooling at the bottom and then exits at the top you get an effective cooling. The hos exiting could easily be lead into a sink or out the garden. If you are ready to put some money on a pump you could just use a large drum or something to contain the water and then since the cooling container is eclosed you can turn the pump on max and then get some very good cooling. This setup could allso be set up in series. Look at the pic and you'll see what I mean.

<a href="http://w1.478.telia.com/~u47804009/E&W/pump.JPG" target="_blank">http://w1.478.telia.com/~u47804009/E&W/pump.JPG</a>

I'm not shure this it what you ment though.

[megalomania]

I think a sealed container might do the trick. I have large plastic jug for pure water. Even a plastic milk jug could do. Just seal some nozzles on it and let the water flow.

[10fingers]

This thread has rekindled my interest in working on my contraption again but I've been pretty busy lately. I will get to it again eventually.
Agricultural suppliers sell bags of ammonium sulphate and calcium hydroxide for less than $10.00 per 50 lb. bag. This is what I will probably use to make my ammonia.
As for the unreacted ammonia, I was under the impression that the catalyst was less than 100% efficient and that consequently you would always have some ammonia exiting from the catalyst chamber. If it were possible to adjust the mixture so that this did not occur, of course this would be the ideal.
I found a good way to monitor the temperature at the catalyst. I use a thermocouple from a gas appliance. You connect a voltmeter to it and you have a crude pyrometer. Of course it needs to be calibrated to the desired temperature. Silver melts at slightly over 900*C so you can place your thermocouple in some molten silver and note the voltage at which it solidifies.

[cutefix]

Qoute:
"Mega, I know this is NOT a complete recipe for the catalyst, but it may give you some ideas."
I have some patent refferences about this ammonia conversion to nitrogen oxides;and indeed there are other economically practical about using cobalt type catalyst;
See this out also..for more details of making related catalysts.
Patent(US)# 3850851
#3767772
#3850851
#1918957

[Mr Cool]

10fingers: Al melts at 660*C, this could be another point to help with calibration. It'd be a lot easier than melting Ag, and not everyone has easy access to Ag.

Personally I believe we will always have lots of nitrates, or if not then it'll be a long time before we lose access to them, so HNO3 can be made from these, either with H2SO4 or by thermal decomposition:
e.g. Ca(NO3)2 --&gt; CaO + 2 NO2 + 1/2 O2
then H2O + 2 NO2 + 1/2 O2 --&gt; 2 HNO3
It'd certainly be a lot easier to use this method, though perhaps not quite as interesting!

[rikkitikkitavi]

ca(NO3)2 starts to decompose at 500 C, and at those temperatures NO2 immediately decomposes into NO+O2 , however they recombine at lower temperatures of course.
But it has to be taken in account for if used in production of HNO3, fortunately the reaction time between NO and O2 is probably very short in the comparativly high concentrations present after the decomposition chamber.

/rickard

[10fingers]

I was not aware that calcium nitrate could be decomposed by heat to give off it's NO2. All you would have to do then is pump it into some water and you would have your nitric acid. Has anyone here ever tried it?
I think part of the allure of the catalytic method is that you could make nitric from just ammonia, air and water. Plus it's an interesting experiment and would be quite an accomplishment to achieve.
And then if you're really a glutton for punishment you could make your own ammonia via the Haber process with just nitrogen and hydrogen. You could make all the nitric you could want from just air and water.
And then your could make your own methanol through the destructive distillation of wood.
And then the methanol could be catalytically oxidized to formaldehyde.
And then with formaldehyde and ammonia you could make hexamine.
And then.........
But by this time your backyard would look like an oil refinery.

[megalomania]

Actually I have thought about other systems to get RDX starting from the saw dust --&gt; methyl alcohol --&gt; formaldehyde --&gt; methanamine route. As it turns out, the same setup I have for making nitric acid can also be used to make formaldehyde. By swapping out the catalyst pipe with some rusty steel wool I could also make sulfuric acid.

I recently read a proposal when researching microreactors about using the reactors as an onsite source of chemical for farming. They calculated that 1000 of their reactors could make a few liters of nitric acid a day. Expanding on this, idea they proposed a means of simulating the entire industrial route from the Haber process and the Ostwald process combined could make ammonium nitrate for fertilizer in one package.
Natural gas is burned with steam to make CO and some H, air is added to complete the combustion giving only CO2 + H2 + N2. The CO2 is removed by an amine scrubber (industrially), but they proposed some kind of membrane filter could do it on a small scale. These gasses would be made into ammonia, the ammonia would be made into nitric acid, and the two would be mixed to make ammonium nitrate.
This kind of thing gets me thinking. With a bit of money to invest this could be a workable setup. It would be marketable to farmers just like they said. I am sure it would be a piece of regulated farm equipment to keep it out of the hands of all those evil terrorists.

[10fingers]

There are a lot of things you can do with a catalytic reactor once you get it working. I've also used mine for making formaldehyde and acetaldehyde. I changed the catalyst to copper sponge. The formaldehyde I seemed to be getting quite a bit but it used a lot of methanol and it was easier to just buy paraformaldehyde. I think the acetaldehyde was working a little but it is so volatile and the temperature of the reactor so high that you really need a good cooling system to capture it.

[frostfire]

Mega, may I know an estimate cost of your distillation setup?, there's one in the dept lab and I'd like to compare the price

[megalomania]

I get my equipment from so many different sources, and I rarely keep track of how much the stuff costs (impulse buys). In short, I have no idea.

[nbk2000]

I was at Wally-Mart yesterday buying a propane lantern because the power often goes out here for days because of the weather.

Anyways, while looking through the Coleman shit, I saw a catalytic heater. After opening up the box and reading the papers inside, I found out that it uses a platinum/pallidium catalyst in a ceramic matting to catalytically burn the propane into harmless carbon dioxide, all while giving off tremendous amounts of heat.

So, what came to mind? Using the catalytic matting to "burn" ammonia and oxygen into nitric oxides.

Something to look into. The heaters are cheap too. Only about $20. :)

[McGuyver]

I've seen these replacement mantle things at wally world. They look like little nets shaped like a bag.

Pyro500, what are you talking about when you say that, when people mess with their converters they forget to adjust their oxygen sensers? What does the c. converter have to do with the intake? I don't get it.

[PYRO500]

Usually the catylitic converter has an oxygen sensor on the input side. Some people that put test pipes in tend to forget that fuel injected cars need an oxygen refrence from a sensor and their test pipes don't have a sensor hole sometimes and they forget to install the sensor in there.

[Jhonbus]

Gas-powered soldering irons like my cooly-named "Flame Master" also use a platinum catalyst in their tips. I don't know how much catalyst you get compared to this lantern, and the tips probably cost somewhere around $5 each. But they are already built into a stainless steel manifold which could be of use in this application.

[vir sapit qui pauca loquitur]

Now, please correct me if i'm sadly misguided, but if i were to set up a pair of chambers (one half the volume of the other) and i was to pressurise the smaller chamber with nitrogen (at about 2000psi) and the larger with oxygen, (same pressure, creating the 2:1 ratio of O2 to N2 ) and i was to open valves from both chambers in to ANOTHER chamber (there-by mixing the gases). would it then be possible to pass a spark across the third chamber for a (long) while would i have NO2 ? (it would be at about 1500/1000 psi range in this chamber while i let it cook,

my next idea woult be to have a pressure regulator allowing the chamber aptmosphere to leak out into a large volume of distilled water, thereby creating nitric acid ???

please correct me if i need higher pressures or this is impossible
we were only taught the MOST basic ideas about the production of nitric acid (due to the liberal government restricting what can be taught)

if this is possible (i need mega or nbk to say that it makes sense)
then i'll start the construction and post pics,

to my knowledge the factors favour it, the products have a lower volume (favoured by equalibrium reactions) and i can heat/cool the reaction vessel by a considerable degree to increase the yield (by finding compromise temperature), and i can have multiple spark units installed. i have read other posts on the subject of spark generation of NO2 but i wanted to know if there was any particular tricks that i could do to increase the rate of reaction (aka kinetic collision formation versus thermal decomposition of NO20

(p.s.) the max pressure that i can generate is about 2000 psi in the mixing chamber (but i prefer 1000 as it is easier to obtain)

[rikkitikkitavi]

if I understand it correctly you want to prodcue NO2 by heating
N2+O2 under high pressure.

First reaction is
N2+ O2 =&gt; 2 NO (high temperature)

NO formed easily decomposes back into N2 and O2. All comercial systems using electrical arcs for heating makes sure that the reaction very quicklu passes the heating zone to maximize yeild.

Second
2NO + O2 = 2NO2 is strongly shifted to NO and O2 at high temperatures.

And if you heat the gases in a pressure vessel , be adviced that a vessel withstanding this pressure loses much of its strength at elevated temperatures, even as low as a few hundred C.

/rickard

[vir sapit qui pauca loquitur]

1. the number of moles of gasses is reduced (2NO + O2 = 2NO2 ) this goes from 3 moles (2 NO plus 1 O2) into 2 moles (2NO2) this means that it is more likely (in an equalibrium reaction which i cant remember that if this is, i think so) and i said that i CAN increase the temp, this would increase the forward reaction (formation of NO2) but also increase the back-reaction (formation of NO) the ideal temperature takes these rates into account, as with a low temp, the formation of NO is low, but the formation of NO2 is also low, due to chemical kinetics at that temperature (and the activation energy of the breaking of the bonds being too high for much formation)

and i do know about charles's law (PV=NRT if i'm correct)
but you see i dont intend to heat up the reaction vessel much, i only intend to let it go on by its own accord and later on in the day i release the gases into water and hey-presto i have a solution of HNO3
... IF this idea is valid (i do understand the limitations of it, as it is a process usually used on the INDUSTRIAL scale)

i have all the parts ready, so i'm just waiting for the A-OK from mr wizard or NBK as to the possibility of
1. explosion (low i believe but i'm not going to ignore advise from people such as the mods)
2. economy of production (if im going to get a tiny yeild unless i'm recycling the gases many times)
if both are to my liking then i'll proceed

p.s. is my sig too big :( [No, the limit is 3 lines]

EDIT [Moderator: Machiavelli ]

thanks Machiavelli, i was worried after seeing some sig's getting you mods a bit on the angry side, better safe then sorry :D

<small>[ September 20, 2002, 06:04 PM: Message edited by: vir sapit qui pauca loquitur ]</small>

[megalomania]

I am not so sure that the usual factors of chemical equilbrium affect the electrochemical reaction you have described. The reaction is largely dependant on electricity, and if I recall correctly, does not favor the formation of NO. With that said I would expect more NO to be formed by higher pressure since more molecules of N2 and O2 will be within the spark field. More sparks will mean more products as well. The temperature should not be a factor. All necessary heat will be provided within the spark only, external heat may only serve to break down your product.

What I see is a vast amount of oxygen being sparked. That sounds inheriently dangerous to me if there is anything besides O2 around. I hope any such container is leak proof to avoid any accident. You will most likely get a large amount of ozone from this reaction as well. Ultimately experimentation will be needed to calculate your yield based on low pressure vs. high pressure, and the economics of electricity consumed. These methods were abandoned by the ancients about 100 years ago because of the more economical Ostwald process, but that dosn't mean it won't work. As I must constantly remind myself, industry is concerned with the bottom line, improvised is concerned with getting A product period.

I do believe there is already a thread that discusses a similar avenue of preperation.

[Marvin]

How thick is the catalyst you are using?
Ostwald's platinum plug was only 2cm thick. You can calculate residence time if you know the surface area of the catalyst, you assume all of the gas contacts it, which if you get neer complete oxidation to NO, it must be. You estimate the area required for a single NH3 molecule, and the residence time falls out of the math. Estimating the surface area of the catalyst might be fun. I cant think of a good way offhand.

Ostwald didnt invent the process btw, he was just the first to do a detailed study of the conditions needed to optimise it. Ferric oxide is supposed to work as well as platinum with an 80-90% conversion to NO possible at about 700C.

I would suggest you get an ammonia cylinder, you need to test each part of this process seperately before stringing it together. Accuratly, reliably and repeatably altering ammonia flow rate is essential for getting this to work, you cant do that with an ammonia generator. If you can find optimal conditions for the catalyst, you can describe it exactly, and so people copying your experiment wont have to test each part seperatly. Optimise in bits using the proper article, then reduce the apparatus to easily available parts.

I would be surprised if there were places ammonia fertiliser was available but not nitrates. I wont be trying this, I value my health too much.

[simply RED]

Very good!
but TOO complicated!!!,
Mega, you remeber the idoine sublimation and purification from the uni?
You remeber the aparatus with the cooling test tube in its center...
Got it?
:) :) :)

[megalomania]

I have completed another round of catalytic nitric acid experiments with rather disappointing results. In several attempts with different setups I was unable to produce any nitric acid using a copper catalyst. There are any of a number of things that could have gone wrong, but I ultimately feel that copper is a bad choice for this kind of work.

My experiments thus far are still relying on the ordinary household ammonia as purchased from the store. I feel this dilute ammonia is more than sufficient to run the reaction even though it presents some moisture problems, as I will explain later.

I did some experiments to determine whether or not flame heat is sufficiently hot enough to sustain the reaction. The original patent literature by Ostwald suggests a minimum temperature of 300 degrees C with a preferable temperature range of 400-500 degrees C. My tests used a Tirill burner at a fairly modest heat could achieve temperatures ranging from 410-450 within 5-10 minutes inside the catalyst chamber as measured on a digital thermometer. I achieved a fluctuating temperature of 430-450 that lowered to 410-430 when the air flow was applied as it would be in my later experiments. A minor increase of the flame size resulted in a temperature increase of 10-15 degrees. I will have to conduct further tests at higher temperatures, but I believe this range is quite adequate for the reaction. It is certainly hot enough to initiate the reaction.

My use of brass connecters and a copper cooling coil at the exit of the reaction tube proved to be a bad choice when using moist ammonia vapors. Ammonia forms hexaaqua copper complexes with copper that also resulted in the formation of copper hydroxide. At one point I obtained a considerable amount of a white precipitate that I hoped was ammonium nitrate. In furnace tests this precipitate should have completely decomposed leaving no residue, whereas copper hydroxide would have converted to copper oxide, a black precipitate. A black precipitate is what I obtained.

I added a lime filled drying flask in later tests that reduced the amount of moisture considerably. Earlier tests without the drying flask left me with several mL of a dark blue copper compound dripping from my joints. Only a few drops of the copper compound formed after nearly 1.5 hours using the drying flask.

In all tests unreacted ammonia was detected in the collection flask, but not enough to account for what was lost from the original ammonia. Surmising that any nitric acid formed would have been converted to ammonium nitrate I boiled down the water of the collection flask. I obtained no solid compound indicating the presence of ammonium nitrate.

Inspection of the copper catalyst after the reactions had subsided show extreme degradation of the material. The moist ammonia as well as air oxidation really takes a toll on the metal. While the oxidized copper should still act catalytically, it is even worse at it than copper itself. The reaction of copper with ammonia absolutely destroys the copper.

My conclusion is that copper is a less than effective catalyst under these conditions. This conclusion would seem supported by the available literature. Copper is a poor catalyst to begin with, it is too reactive, and has a short life span during the reaction.

<a href="http://www.roguesci.org/images/NA-June-03_01.jpg">My experimental design</a>
<a href="http://www.roguesci.org/images/NA-June-03_02.jpg">A close-up of the ammonia boiler</a>
<a href="http://www.roguesci.org/images/NA-June-03_03.jpg">A close-up of the catalyst chamber</a>
<a href="http://www.roguesci.org/images/NA-June-03_04.jpg">A close up of the cooling coil</a>
<a href="http://www.roguesci.org/images/NA-June-03_05.jpg">A close up of the collecting flask</a>
<a href="http://www.roguesci.org/images/NA-June-03_06.jpg">The setup with the drying flask</a>
<a href="http://www.roguesci.org/images/NA-June-03_07.jpg">Copper hydroxide precipitate</a>
<a href="http://www.roguesci.org/images/NA-June-03_08.jpg">Before and after catalyst example</a>

[blindreeper]

Very nice pictures there mega. I think what your saying is that the copper doesn't work as a catalyst no? Well why not try 10fingers idea (sorry if it was some one else) well not really his idea but he did it and extract the pallium/platinum catalyst with aqua reigia. Or maybe just using the cat converter straight. Then of course that isn't exactly OTC. Meh I'm tired

[knowledgehungry]

Maybe you should try a platinum catalyst, platinum is OTC just not cheaply(jewelry). If the platinum catalyst works than you could look for a cheaper catalyst. but it would seem that you would want to make the setup works in the first place.

[kingspaz]

if you need platinum go to the scrap yard and rip a few catalytic converters from some old cars. they should already have a decent surface area.

[megalomania]

Yesterday I tried the experiment again, but this time I used a platinum catalyst. I crushed up a portion of a used catalytic converter and added it to my tube with copper sponge plugs at either end to hold it in.

I am happy to say I got absolutely nothing… That is progress, believe it or not, because there was no trace of ammonia whatsoever in the collection flask this time. I at least know there is a reaction because all of my ammonia is decomposing. I did add a rather large amount of catalyst, but I figured most of it is so choked with carbon that extra is needed.

I will be trying the experiment again today with a fresh batch of ammonia and fresh lime in my drying flask. I shall remove half of the catalyst as well.

I have also prepared a catalyst tube of manganese dioxide. I dusted cotton balls with MnO2 and stuffed them in the tube. I then heated the tube with an air flow to burn off the cotton. After 10 minutes or so no more smoke came out. The next day when I examined it there was considerable ash falling out. I hope it does not settle and make a gap that the ammonia can pass through unreacted. Perhaps dusting moist (so the MnO2 cakes) iron wool would have been a better choice.

[10fingers]

When I tried this experiment I learned one thing, it's not that easy. I also used household ammonia and heated it. With a platinum catalyst I definitely did get some NO2, there was quite a bit of reddish brown fumes coming out of the reactor. However it would come and go and was difficult to sustain. Also it seems to take a whole lot of NO2 to make any nitric acid. After awhile it quit working and I was not able to get it going again. Perhaps the catalyst was contaminated with something.
I agree with Marvin, the amounts of air and ammonia need to be closely controlled, also the pressure and speed of the gases through the reactor.
If I tried it again I would use a more concentrated source of ammonia and I would use adjustable pressure regulators for both the air and ammonia. It's pretty easy to concentrate household ammonia, but it gets expensive. One could buy a tank of the stuff but anhydrous ammonia is also used to make meth and I don't think I would want to have a bottle of it around. Another way I might try is to mix ammonium nitrate and calcium hydroxide. I can get both of these from the agricultural supply for around $6.00 per 50 lbs. You could put this in a pressure cooker with a regulator and pipe it into the reaction chamber.
I found a patent at the USPTO that explains in detail how to make nitric acid for agricultural uses. It's kind of a do it yourself for farmers that want to make their own fertilizer. The process used a cobalt oxide catalyst. I have found cobalt oxide at a ceramic supply co. It's used to color glazes. It's rather expensive though, $27.00 for 1/2 lb. but it's a lot cheaper than platinum.
The other thing is that once the mixture is right all you need to get the reaction going is a spark plug. You just fire it and the air/ammonia starts to burn and once the catalyst gets hot, you don't need to supply any more heat.

[megalomania]

Oh good, this thread is on top, saved me from having to look for it…

I will shortly be obtaining some additional equipment necessary to more thoroughly test this experiment. I will be getting a cheap almost new catalytic converter to supply the necessary catalyst. I still think there is nothing better out there than this, it has the best catalyst and is already shaped perfectly for a catalytic reaction. A single cat will probably last a lifetime.

I will also probably be getting a decent second hand mass flow meter. With these I am slightly out of my league because these are professional instruments. Omega sells dozens of models of varying configurations, so I have no idea which one is best suited to my needs. I don’t even know if a mass flow meter is the right way to go, but it happens to be all I can get cheap. These things go for $500-$800 depending on the model when bought new.

From what I can gather a mass flow meter measures the quantity of a gas passing through it based on a calibrated standard at STP and nitrogen gas. I will be using it to measure the flow of ammonia, but there are published conversion factors to get an accurate result. I don’t really care about the amount of gas, just the velocity of gas over the catalyst surface. All things remaining equal an increase in the mass flow should equal an increase in gas velocity over the catalyst. Really a simple rotometer gas flow measuring device might do the trick, but I can get the computer controlled digital meter for the same price.

The problem I have in picking a mass flow meter is knowing which maximum flow rate to get. These things are measured in standard feet per minute, or standard liters per minute. They also come in standard cubic centimeters per minute, and in inches. The one meter I saw has a max of 1 L per minute. That hardly seems sufficient to me. The one I am considering now goes up to 50 L per minute. That should be more than enough, but I don’t know how that is graduated. I guess I won’t know what I need until after I buy it, use it, and find out it is no good.

On the ammonia front I am going to try to use a real anhydrous ammonia tank if I can get one. This is another thing the druggies screwed up for the rest of us. I am not sure ammonia is illegal per se, but sellers may be wary of anyone not a licensed refrigeration expert. Failing this I will just make my own from fertilizer and store it in a pressure tank.

I still have to build my temperature controller and improvised electric furnace. I was also thinking about testing a small copper wire system using an arc welder as a heating source. I would hook the wire up to the electrodes and just blast it with a high current power source to see if the wire will heat up. Once the copper is at red heat the reaction should be self sustaining.

I found this company today while searching for ammonia suppliers: http://www.brainerdchemical.com/frameset_nitr.htm They sell nitric acid. If you click the "view our nitric acid products link" you will see they are selling 55 gallons of technical grade nitric for $131.32 + a $500 drum deposit. I think you get the deposit back. That is damn cheap, especially considering all their other prices. I wonder if that is a typo, it is probably supposed to be $1310.20.

[zerok]

Have you thoughed of using a pitot-static tube?
http://www.du.edu/~jcalvert/tech/fluids/fan.htm

What it basicly does is measure 2 different pressures. With those pressures you can calculate the speed of the airflow.
What you need is some sort of setup described on the webpage. A hole in the wall of the tube where you want to measure the speed connected to a U tube field with a fluid. a small tube with an open end in the middle of the tube connected to the other side of the U tube. The difference in fluid height in the U tube will be the pressure difference which can be calculated to speed.

I hope this is a usefull first post :)

[10fingers]

That's a very low price for nitric acid! I have never found anything that low. I wonder if it's correct?
Using a new catalytic converter would probably help. The ones you get out of the junkyard may be contaminated or have all the platinum burnt out of them.
The catalyst I used was was the ceramic honeycomb type. It's very easy to cut with a hacksaw. I just cut out a circular piece to fit into the piece of stainless steel pipe I was using for the reactor.
I think buying anhydrous ammonia these days is definitely going to raise eyebrows with all the meth making going on.
Probably the main drawback I can see to the process is can you make or obtain ammonia at a cost that makes it worthwhile. It may be more trouble to get the ammonia than it would be to make nitric with H2SO4 and a nitrate or buy it.
But I think it's an interesting project and I often go to great lengths and expense just to see if something can be done. It's not a matter of it's practical or not. It's a challenge.

[megalomania]

I would think compared with nitrate/sulfuric the cost of ammonia would be about the same, or less. It is more work getting the ammonia of course.

[kurtz]

I was looking in Ind. Eng. Chem. at a picric acid article yesterday, and noticed that the next article (http://rapidshare.de/files/3346985/iec_16_74_1924.pdf.html) was an interesting and detailed one, testing a variety of inexpensive, mostly Co3O4 catalysts on a small scale. In one example, 22 L/min air/NH3 and 14 g. 97% Co3O4/3% Bi2O3 catalyst @ 710-730C was calculated to yield 8.36 g. HNO3/minute, with >94% conversion of the NH3. The author mentions a patent that he was granted for one of the many catalysts that he tested and its use, US1399807 (http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US1399807&F=0&QPN=US1399807).

[kurtz]

I was looking in Ind. Eng. Chem. at a picric acid article yesterday, and noticed that the next article (http://rapidshare.de/files/3346985/iec_16_74_1924.pdf.html) was an interesting and detailed one, testing a variety of inexpensive, mostly Co3O4 catalysts on a small scale. In one example, 22 L/min air/NH3 and 14 g. 97% Co3O4/3% Bi2O3 catalyst @ 710-730C was calculated to yield 8.36 g. HNO3/minute, with >94% conversion of the NH3. The author mentions a patent that he was granted for one of the many catalysts that he tested and its use, US1399807 (http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US1399807&F=0&QPN=US1399807).

[meselfs]

Whoa! But 700 C might be a bit too much for us. Can some sort of coil acheive and maintian that temperature without making the outlets turn hot and smelly?

[meselfs]

Whoa! But 700 C might be a bit too much for us. Can some sort of coil acheive and maintian that temperature without making the outlets turn hot and smelly?

[megalomania]

There are several very good articles in Ind. Eng. Chem. all of which I happen to have... History, I am afraid, has shown again and again the platinum is by far the single best catalyst to use. Of course it is quite encouraging to know that there are many different alternatives that rank "nearly as good" as platinum.

I have used manganese dioxide and copper sponge with little success. Now I have a platinum catalyst. Start with the best then figure out the rest I say. It is the experimantal setup in this articles drawing that is most encouraging.

[megalomania]

There are several very good articles in Ind. Eng. Chem. all of which I happen to have... History, I am afraid, has shown again and again the platinum is by far the single best catalyst to use. Of course it is quite encouraging to know that there are many different alternatives that rank "nearly as good" as platinum.

I have used manganese dioxide and copper sponge with little success. Now I have a platinum catalyst. Start with the best then figure out the rest I say. It is the experimantal setup in this articles drawing that is most encouraging.

[Alexires]

Hey mega, what is the chances of getting the images put back into this thread? I'd like to see your set up.

Sorry to be a pain.

[tmp]

Mega, I wish you the best of luck in making nitric this way. It seems that
someday we'll all have to produce our own chemicals. I already produce my
own metal powders, chlorates, and perchlorates. It proves how fucking
useless the laws really are. I've made white fuming nitric via the vacuum
distillation of nitrate/sulphuric acid. Your method intrigues me. Any photos
of your setup would be greatly appreciated when you have time. Thanks in
advance !

[inventorgp]

Has anyone thought of using a high voltage transformer?
Get two electrodes encase them in a glass chamber, turn
the power on and let it arc.

Air -> NO2.
2N + 4O -plus HV-> 2NO2.
Please correct me if I am wrong,
although I think this is correct

Then bubble it in to water.

An easy to get transformer is a MOT -
Microwave Oven Transformer

I have about a million of these, space consuming and heavy:p

An apparatus could be set up; air compressor - arc chamber - water

[c.Tech]

Has anyone thought of using a high voltage transformer?
Get two electrodes encase them in a glass chamber, turn
the power on and let it arc.


I think you’re in luck.

http://www.roguesci.org/theforum/special-project-1-nitric-acid/1919-hno3-air-using-electric-arc.html

http://www.roguesci.org/theforum/special-project-1-nitric-acid/4181-nitric-acid-air-water.html

The link "http://species8472.dyndns.org/no2/no2.html" contains detailed non-kewl information.

He also makes sulfuric acid using catalyst and does various other interesting experiments.

[inventorgp]

c.Tech kewls don't know how to do anything.

And are you suggesting I am one, I Think not

Yes It is a quick description.

If you are not implying this then I apologise:D

I don't have enough funds to do such experiments or
as much knowledge to produce a fully capable apparatus.:(

I consider the term "kewl" to be an insult, kewl as in lacking brains.

[c.Tech]

I wasn’t calling you a kewl, sorry it was set out that way :o , I said "non-kewl" because there is a lot of shit floating around on the net and I was trying to emphasize that it was good experiment, which still doesn’t make much sense of why I put it in, even to me :confused:.

It was quite irrelevant, I didn’t really think before I wrote it.

[fractional distiller]

I am very new to synthesizing explosives and especially to synthesizing acids to be used in explosives. I have been researching and saving money for some time now so I can buy myself a fractional distillation setup. My question to all of you more experienced and knowledgeable individuals is if I buy my glassware set from

http://www.unitedglasstech.com/distillingKIT8.htm

along with this vacuum from united nuclear

http://www.unitednuclear.com/vacpump.htm

would it be the type of vacuum I need? I am also concerned that the fumes from the distillation of sulfuric acid will destroy the vacuum and then the vacuum distillation of sulfuric acid and potassium nitrate to produce my fuming white nitric acid will corrode the pump although it claims to have oil that is supposed trap these impurities and corrosive gasses. Do you think that these two pieces will be the set up I will need?

Any and all help would be greatly appreciated.

[megalomania]

On first glance that is a decent kit. However, a few seconds later I realized this is not appropriate for you at all. First and foremost the flasks are FLAT BOTTOMED. You do not want to use flat bottomed flasks in a vacuum operation because they are not designed for low pressure work. Only ROUND BOTTOMED flasks are vacuum safe. Unless a flask is specially reinforced, like a heavy walled Erlenmeyer, you need a round bottom for vacuum work.

Second, those two flasks are quite large at 1000 mL and 2000 mL. I am not saying it is bad to have a flask that large, but you need to factor in what kinds of reactions you are doing. I have rarely needed to use anything beyond a 500 mL flask, and I try to confine most of my experimentation to 25 mL and smaller. Microscale is the wave of the future. Of course, if you are planning on manufacturing something in larger batches, like acid, large is good. I think the only manufacturing some of the typical customers would have in mind is of the recreational pharmaceutical variety.

Also, keep in mind how you will heat such a large flask. Heating mantles abound for smaller sized flasks, but bigger sized ones cost big bucks. You may have to use an oil bath, sand bath, or build you own steam jacket. If inorganics are your bag, then there is nothing wrong with using the ol Bunsen burner.

A Vigreux column is nice, but personally I prefer a glass bead filled Liebig. I can swap out the glass for copper sponge, ceramic, plastic, etc., depending on what I wish to distill. It lets me keep my options open. I think a glass bead filled column offers more theoretical plates than a similar sized Vigreax, depending on the size of the beads. That Vigreax column should be just fine for acids though.

Personally, I prefer to shop at a company called Chemglass Scientific Apparatus at chemglass.com. They have a large selection of standard taper glassware. Get their free catalog. I find their prices to be very reasonable as far as standard taper glassware goes.

The vacuum pump at UN is a very decent price, assuming the quality of the pump is up to par. A good pump can run you well over $400, but there are cheap models. The manufacturer and model number of that pump is not specified, which I consider to be a bad sign. As vacuum pumps are reckoned, some would not consider 40 microns to be “high vacuum.” Something seems fishy to me. They do not specify the horsepower of the pump, nor do they mention the CFM pumping capacity. CFM is cubic feet per minute, a rating of how fast the pump will remove a certain volume of gas.

To protect your pump from acid gasses I suggest you install a trap on the line capable of adsorbing acid fumes. I am not sure of the exact setup, but google is your friend there.

[wymanthescienceman]

Hi all! I've been looking into distilling nitric and have a few questions and I couldn't find them by searching the forums, the search engine sucks balls. But here they are:

When distilling HNO3 by mixing a nitrate with H2SO4, will the HNO3 be only as pure as the H2SO4 used? I was planning on using a cheaper alternative to my 98% H2SO4 by using a drain opener which is roughly ~90% H2SO4, the rest being water and some kind of inhibitor dyed brown. So being 90% will my HNO3 be AT BEST 90% pure? Also will the inhibitor have any effect on the outcome of the HNO3? I can't distill under vacuum yet but I was thinking of doing it the way seen on the "Nitric Acid the Easy Way" thread by using a vessel inside a vessel and catching the HNO3 by condensing it on a glass or saran cone in the outer vessel, using a water bath at about 60-80C.

I think I'm going to try this and see what happens anyway and I'll post after I try, but what do you guys think about the final water content of the distillate I will get, and if I do it under vacuum will it be better? I mostly will be using the HNO3 for nitrating experiments but not RDX so it doesn't have to be 100% obviously.

[nbk2000]

Oh boy...

Dude, this whole section is nothing BUT nitric acid and related questions. Read, read, and read some more.

Some words that might help with a search are 'mixed acids', 'nitrating', 'drain', 'anhydrous'.

[c.Tech]

Another handy search tip: If you can't find information on the forum or google but are sure it must be around the forums somewhere you can search quotes.

Because Rouge Science is a public forum web spiders are free to browse as they wish so google is sure to have the forum stored somewhere on their database.

Go to google, type in a quote eg. "mixed acids" then let google know the site it's to be searching by typing 'site:www.roguesci.org'

Now in total it should say...

"mixed acids" site:www.roguesci.org

Putting the words in quotes only looks for those two words aside of each other, I’ve found it very useful so far.

[megalomania]

The purity of your distilled nitric acid depends on what exactly the contaminants in your sulfuric acid are. Nitric acid is a relatively volatile chemical, and as such it should be rather pure after distillation. I would suggest redistilling the pure nitric acid after you make it if you are concerned.

You will absolutely get a purer and more concentrated nitric acid from using vacuum distillation. Distilling nitric acid under atmospheric pressure leads to an increase in decomposition of the acid, and to much larger quantities of water distilling over.

[tmp]

I won't risk my mechanical(rotary vane) vacuum pump for making HNO3.
I use it for for air-conditioning work. It pulls 29" of Hg - more than
sufficient for A/C. My cheapass little glass aspirator(cost me $9) is the
best vacuum source I have for chemistry. Slower than the mechanical
pump but does a good job with nitric in the winter months when the water
is very cold. I keep the H2SO4/KNO3 mix below 60C to prevent the damn
decomposition. An added benefit - obnoxious fumes go down the drain.
This thing also works great with filtration flasks. The hand pump that came
with the flask wears out my hand.

[megalomania]

Use a trap between the nitric acid and the pump. A vacuum flask, or even a mason jar, with a little base (like NaOH preferably) will neutralize any acid fumes that do not condense.

The acid fumes are bubbled into the base solution, and the vacuum source is above the liquid level in case anyone was wondering how that works.

The sophisticated version: 'http://www.ars-fla.com/images/Accessories/ADS-Bubbler.jpg'