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Author: Subject: alternative oxidizers for hydrazine production
Al Koholic
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[*] posted on 19-11-2003 at 22:09


To form hydrazine nitrate you'd really need nitric acid...

Starting with hydrazine sulfate yes I suppose based on the dissociation constants you could theoretically (if the hydrazine nitrate is less soluble in water than hydrazine sulfate which it might very well be based on anion stability) ppt hydrazine nitrate while leaving ammonium sulfate in solution. This would be a poor way of conducting the production though. Much easier to put the free base into solution and then acidify with nitric acid.

Ammonium nitrate and freebase hydrazine would be basically impossible to get hydrazine nitrate from.
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Iv4
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[*] posted on 20-11-2003 at 02:47


I'm thinking about the hydrate then?
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chloric1
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[*] posted on 20-11-2003 at 08:04
free base


Hydrazine can simply be liberated from the sulfate in liquid anhydrous ammonia because ammonium sulfate is insoluble in the latter. THe difficulty is in handling the anhydrous ammonia as it boils at -30C.:o

[Edited on 11/20/2003 by chloric1]

[Edited on 11/20/2003 by chloric1]




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[*] posted on 21-11-2003 at 02:48


Bubled through it maybe?

If ammonium nitrate and hydrazine dont form hydrazine nitrate whats is the fuel astrloite really?Not being prick just curious.
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KABOOOM(pyrojustforfun)
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[*] posted on 25-11-2003 at 20:35


Theoretic:
<blockquote>quote:<hr>(N2H5)2SO4 + Ca(OH)2 => CaSO4*2H2O + 2N2H4.
(N2H5)2SO4 + CaO => CaSO4*H2O + 2N2H4 <hr></blockquote>
the insoluble sulfate isn't (N<sub>2</sub>H<sub>5</sub>;)<sub>2</sub>SO<sub>4</sub> it's N<sub>2</sub>H<sub>5</sub>HSO<sub>4</sub> also the reaction with CaO is veeeeery exothermic making the hydrazine decompose in situ :D
to get HN from HS just mix a boiling HS sol with barium/calcium nitrate sol => filter. I don't know anythin about the solublity of HN in alcohol but have the feeling it dissolves, if so, one can use almost any metal nitrate, boiling most of the water away after mixing the sols => sinking the crystals in alcohol => filteration => evaporation => ready for *x***sion :D




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Chris The Great
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[*] posted on 22-9-2005 at 17:30


Tested a preparation of hydrazine sulfate using TCCA and urea. It was extremely easy and fast, however I am unsure if what I has is actually hydrazine sulfate and not something else (cyanuric acid?). My scale is not very accurate and so the amounts were probably off by a fair amount...

The general reaction should be something like this:
(ClNCO)3 + H2O --> (HNCO)3 + 3HOCl
3HOCl + 3NH2CONH2 --> 3N2H4 + 3HCl + 3CO2
3N2H4 + 3H2SO4 --> 3N2H6SO4

Approximately 18g of urea was dissolved into 100mL of distilled water. Approximately 20g of TCCA was added to a fair amount of distilled water. Not much dissolved despite my stirring. Then, 25g of sodium hydroxide was added, causing some foaming that immediately vanished when I started stirring again in a hurry (local overheating I think). Nearly all of the TCCA dissolved, leaving some chunks. I decided to add another 10g of NaOH since I think it had absorbed some moisture, and wouldn't be enough to take up the HCl generated. Once this was added all the TCCA dissolved leaving a solution the colour of milk. It cleared up when some more distilled water was added, leaving a warm, clear, yellowish solution.
The solution of urea was slowly poured in while rapidly stirring, giving off the expected rapid foaming. The mixture would foam up vigourously and then die down after approximately a second, and then more urea solution was added. The foaming stopped after about half the urea solution was added, but the rest was added anyway although more rapidly. The solution was still clear but was less yellow at this point.
A hot solution of 25mL distilled water and 20mL conc. sulfuric acid (I didn't bother to wait for it to cool, I just didn't want it to release all the heat rapidly in my hydrazine solution) was added, which caused more foaming (???). No precipitate was noted at this point, but a very fine amount formed as the solution cooled slightly (it was very hot by this point, probably >80*C). I put a lid on it and stuck it under the hose to cool it, this gave me a layer of white, very slightly grey precipitate, although the solution was still warm.
It's now sitting on my lab bench to cool down completely before I filter out my (hopefully) hydrazine sulfate.

If it is hydrazine sulfate, I'll try to optimize the procedure, I think using hot water for the TCCA/NaOH solution will help reduce the volume of water needed to dissolve them. I don't think NH3 would work as well because it is pretty hot, although presumably it can be done at lower temperatures the low solubility of TCCA will bring us back to the problem of having to use large volumes of dilute solution.
I think that an optimized procedure could easily give 400g hydrazine sulfate using a 4L pickle jar :D

Now, I do have a question- since no-one seems to have tried this method before, I'm not exactly sure what I have is hydrazine sulfate. It could merely be cyanuric acid or something. Is there some easy, simple, OTC test to see if what I have is hydrazine sulfate?

I have some high hopes for this procedure, I found it very simple and had no problems at all. Hopefully none will crop up when it is scaled up.
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[*] posted on 22-9-2005 at 17:35


If you are to react your hydrazine with NaOH to form the hydrate, the hydrate should react with Silver nitrate to form a silver mirror. Other metal salts should work as well as hydrazine is such a powerfull reducing agent.



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Chris The Great
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[*] posted on 23-9-2005 at 19:36


I did a quick test using iodine tincture (didn't have anything else on hand), and sure enough after a faily vigorous reaction with NaOH, an alcohol solution of what was presumably a small amount of hydrazine hydrate caused the strong I2 colour to immediatly vanish.

:D

Unfortunetly, I was unable to scale up the reaction. I have found out the hard way that TCCA readily decomposes into very irratating, very strong smelling gases when heated. I was using hot water to dissolve it to increase the solubility, and was rewarded with something that burns my respiratory tract like chlorine, has a very different and much more penetrating odour, and burns my eyes like hot ammonia.
I suspect this is some oxy-acid of chlorine or chlorine oxide of some sort, but cannot figure out exactly what it would be...

In this case I used 200g TCCA, 750mL of hot water. Decomposition set in soon after mixing, but stopped when cold water was added. It started again and wouldn't stop when I started adding NaOH.
I tried again, using cold water, and was rewarded with a more controllable problem- as long as I kept stirring it didn't seem to decompose, but as soon as I stopped it sat quietly for a few seconds and then started bubbling like crazy. It seemed to be energetic, as it increased in speed as time went on.

I do not know what this chemical could be, I am betting HOCl gas, but apparently that only exists in solution.

I think this is because of the strong heating caused by the addition of NaOH.

I therefore propose two possible actions:
-Use highly concentrated NaOH solution to greatly reduce the heating
-Add all the NaOH at once to prevent the TCCA from decomposing much in the first place
I would like to hear others thoughts before I continue however, the smell was highly unpleasant and being unable to breath while having your eyes tear and burn is not something I wish to repeat. I still think this method has possibility, but has some annoying problems that need to be worked out.
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12AX7
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[*] posted on 23-9-2005 at 20:00


Well, first of all you have to prepare a basic TCCA solution, which means 1. NaOH + H2O = heat of dissolution; 2. TCCA + H2O apparently = heat of decomposition; and NaOH + TCCA chlorine = neutralization heat. Sounds to me like you should include some ice cubes in the next preparation. :)

I would recommend starting with an oh, 10 or 20% NaOH solution (remember, more water = more heat capacity!), cool it down, add TCCA and ice cubes and see where it goes.

BTW, can you start with urea sulfate and oxidize it to hydrazine sulfate?

Tim




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Chris The Great
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[*] posted on 23-10-2005 at 19:39


Well I tried a slightly different procedure, cold water and sodium bicarbonate as the base, hoping it wouldn't case the problems that NaOH had been causing.
Long story short, I ended up with the same painful gas being evolved, and when I added urea there was no foaming but chlorine was produced as well. So I don't think that this procedure will work very well, TCCA decomposes in the presence of a base seemingly, and the base is needed to take up the HCl generated or it will produce chlorine with the TCCA.
I think I will try adding urea and sodium bicarbonate in one solution over time to TCCA, but if that doesn't work...

However, I did have what will hopefully turn out to be a good idea. The problem I keep finding with TCCA is that it has a low solubility in water. However, it is very soluble in acetone, as is... ammonia!
So, I was thinking:
ClNCO (TCCA) + NH3 --> HNCO (cyanuric acid) + NH2Cl
NH2Cl + NH3 --> N2H4 + HCl
HCl + NH3 --> NH4Cl
Cyanuric acid and ammonium chloride are insoluble in acetone, and precipitate. Hydrazine is soluble and remains in solution. Insolubles are filtered out, acetone boiled off and anhydrous hydrazine remains.
:D
Thoughts? I'll be trying it when I make some 30% anhydrous ammonia in acetone solution. A fair excess will be used as it seems excess ammonia leads to higher yields. Also, no heavy metal ions to screw things up.

I just have this feeling something will go wrong, like my other attempts at hydrazine using TCCA....
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[*] posted on 24-10-2005 at 01:03


Hydrazine and acetone will react to form a ketazine, though that can be hydrolysed back to it's components. Also ammonia and acetone form some polymers + other odd things.. So I think acetone isn't the best solvent for your reaction.

[Edited on 24.10.2005 by IPN]
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[*] posted on 24-10-2005 at 02:18


I get the vague feeling that this might form NCl<sub>3</sub>. Being intimately mixed with a good reducing agent (the acetone), you might have a problem here. I’d suggest trying this on a test tube scale first.

On the other hand, the other reactions also seem like they would form some NCl<sub>3</sub>. Can anyone explain why they don’t?
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[*] posted on 24-10-2005 at 14:56


I think it's because there is always a large amount of ammonia, so that forming NCl3 isn't really favourable since it could just form 3 NH2Cl's.

As for the solvent, I will try acetone, see if it works, if not, I'll try some other solvents that TCCA is highly soluble in. The TCCA solubility seems to be the main problem with using it for making hydrazine, as it will be extremely dilute if dissolved into water which defeats the purpose, just use bleach in the normal method.
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[*] posted on 4-8-2010 at 20:56


I'll post this because it is one of the better "theoretical" syntheses (that look legit) that I have seen, it uses NO gelatine, but does use Mn salts to make hydrazine sulfate from sodium hypochlorite and urea. The attached paper also details the liberation of the hydrazine hydrate & the dehydration thereof.

PS I quite like this book, who did I pinch it off?;) It has updated routes to a lot of very nice to have inorganic intermediates.

Attachment: Vorobyova.Practical.Inorganic.Chemistry.1987.pp.139.141.Hydrazine.Hydroxylamine.pdf (172kB)
This file has been downloaded 877 times





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