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Ral123
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[*] posted on 20-5-2012 at 06:27
Runaway reactions


I just had a therible egdn runaway. It was moderately big batch of 80ml fuming nitric and about 120 sulfiric. The expected yield was minimum 50ml. I did all the nitration nicely, about 50ml eg in total used. I got it off the cup of ice and placed it in 1,5l moderately cold water. stirred a little and went inside to eat. At the 10-th minute of the starcraft2 cast I was watching I kinda hear something, look at the widow and OMG. Heavy bronwnish-yellow smoke some if it gets in the apartment...oh shit. Closed doors and windows and pray?? When it became less vigorous I poored one liter cold water around the beaker. After a while I stuffed a big icy chunk in it. After a while I let the beaker's contents in the surrounding water. Now it's kinda scary what could have happened considering that after all that there is absolutely no egdn left. I've done runaway tests before but that's the ultimate. I think I deserve the next title after hazard to self :D Is it possible that there was unreacted eg? Till the end of the reaction the temp was 20C, it's not like I add eg when it's 10c and it all reacts at once. Usually I use more sulfiric and in the end the egdn makes a top layer. In this case the densities were very similar and almost all the egdn was in the form of miniature drops I think. Can you share your experiences with these things. What can go wrong with ng, eritritol, etanol?

[Edited on 20-5-2012 by Ral123]
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hissingnoise
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[*] posted on 20-5-2012 at 06:35


Quote:
What can go wrong with ng, eritritol, etanol?

You can nonchalantly walk away again . . .
I'd have thought that the need for temperature control and continuous stirring during organic nitrations would be obvious to just about everyone?

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Ral123
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[*] posted on 20-5-2012 at 06:57


At the end of the reaction not much happened when I add more eg. The temperature seemed stable, not changing for 5 mins when the beaker was in the large volume cold water...and I went inside.
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rollercoaster158
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[*] posted on 20-5-2012 at 08:35


Never pour a runaway nitration mixture into water! The sulfuric acid will heat up vigorously with the water and drive your runaway further.

H2SO4 + H2O = HSO4- + H3O+





And it's only 200 calories!

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Adas
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[*] posted on 20-5-2012 at 11:03


During nitrations, you must stir it, because the liquid that is not in contact with the sides of the glass is likely going to overheat.



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TheMessenger
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[*] posted on 20-5-2012 at 18:41


I had that exact same thing happen with RDX...

I brought it up to 50C. Stabalized the temperature... And it appeared to be holding level. Took it off the double boiler and assumed it would just cool down radiating off heat into the cement... Come back ten minutes later and there is a orange steaming volcano going!
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Ral123
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[*] posted on 20-5-2012 at 22:11


I've had the 50C+ RDX runaway also. No yields after :( But 50ml egdn decomposed in a few minutes in an apartment's balcony :o I wonder if it was MeNO3 would it have gone kaboom baby :o Or NG?
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hissingnoise
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[*] posted on 21-5-2012 at 01:04


I had a runaway while distilling MeNO<sub>3</sub> from 68% HNO<sub>3</sub> in a 2 Lt RBF.
Just as well that I was on the spot to yank the adapter from the flask on seeing the first tell-tale bubbling . . .

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hissingnoise
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[*] posted on 21-5-2012 at 03:35


If anyone else is foolhardy enough to try this, small quantities only of reactants should be used, for safety's sake!
A runaway can hinge on just 1°C or two over the b.p..!
And anyway, MeNO<sub>3</sub> is too volatile to be of much use . . .

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[*] posted on 24-5-2012 at 15:08


I met such reactions more than once. NG- all of you folks know, how it happens, therefore I have no need in detailed explanations. TNP- thrice. The first experiment gave me boiling mixture and red fume of NO2. the second - I added some sulfur acid to mixture of KNO3 + phenol and got ignition. the third I made when I had already known right method., but i made an experiment- I took AN instead of KNO3. Reaction went much faster and I got a foam, full of NO2 and growing in volume. My vessel was overwhelmed. Gun cotton- it was really interesting, because violent reaction occurred, when I washed piece of cotton in water. probably, I did it not enough quickly and contact of mixed acid with water caused overheating. Violent reaction leaved bubbles of NO2 and some coal. RDX- it was not really runaway, but something close to it. I prepared conc HNO3 and put some hexamine into it. Bubbles of NO2 and no desired compound at all. Hexamine was simple burned by HNO3. Later I read, that I had to use white fuming nitric acid, not red. May be, but when I used hexamine dinitrate instead of pure hexamine, I got no oxidation and got some RDX.



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[*] posted on 30-5-2012 at 21:25


Say, if you don't dump a runaway, what are you supposed to do with it? Let it go?? Anyway, I had a curious runaway event with TNP. My first. 200ml tech-grade SO4/50g ASA/35g KNO3. This is almost twice the ASA ratio I usually use, but not the largest (unless I read something wrong, Barrows cites .5g ASA :: 80ml SO4) I heated the SO4 on a coffee maker hotplate for 20min( I never use a thermometer with TNP), then added ASA in 5 portions. Continued heating for another 5min and removed from heat. Stirred and let stand for 20min. The ASA had not dissolved so after aggressive stirring and another 15min without complete dissolution, I returned it to heat for another 10min. The ASA finally dissolved. I let stand for 15min until about tapwater hot (this is the temp I've ALWAYS used - 6 pprior runs). I began adding KNO3 appx 5g per addition. At the 3rd addition the foamup failed to settle. After fuming ceased, stirred down the foam and continued addition. Half way through the last addition the mix became VERY hot and started fuming white. I stopped and stirred and let stand. After appx 3-4min the mix began to boil and produced heavy white fumes. I began light irrigation of the vessels exterior and the temp dropped and fuming nearly ceased. within <1min of halting the irrigation, the fuming started increasing and temp rising rapidly. At this point I set the vessel in an irrigated bath. The temp dropped but substantial fuming(white) continued for another 5min before I gave up and drowned it in 500ml ice water. The ice never melted and the water temp didnt seem to rise. There was no foaming and minimal red fuming. Yield was so low I didnt bother measuring(<1g), but the water was cloudy and bright yellow as normal. My question is- what the heck happened? Any thoughts?
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Ral123
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[*] posted on 31-5-2012 at 01:12


I dont have any experiance with aspirin, but if I get enough of it, I'll definitely nitrate it. Can we make a top 10 runaway danger list. May be MeNO3 should be somewhere in it? RDX runaway is a walk in the park, exept it ruins yelds. Mixture of toluene and NA doesn't react usualy, but when it does it nitrates my face :( And I'm not even in soviet russia :D
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hissingnoise
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[*] posted on 31-5-2012 at 01:36


Quote:
Mixture of toluene and NA doesn't react usualy, but when it does it nitrates my face.

Nitrotoluenes are toxic, should be handled with care and certainly shouldn't be allowed to get on the skin!

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[*] posted on 31-5-2012 at 14:31


BTW that should have read 'Barrows cites .5g ASA/ 1ml H2SO4'. I've tried TNT and TNN but failed miserably. Done RDX twice with good results. But the TNP runaway was completely unexpected. Never tried Nitro or Metyl Nitrate for fear of runaway. Not so much fear of injury by detonation, but rather nitrating myself in a shower of hot acid. Oh, I HAVE done test tube MN, if that counts? If I may ask, whats the problem with acquiring aspirin? Or was that a joke of some kind?
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Ral123
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[*] posted on 1-6-2012 at 02:41


New medicine grade aspirin would cost me per gram more then rdx. What is TNN and how do you fail with TNT? Btw nice fail topic I've started :D
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[*] posted on 2-6-2012 at 02:34


TNN is Naphthalene Dont know where everyone's from, but thats mothballs)- very similar to TNT. dunno kids may call is something else these days. I see so many letters, now. Information age, huh? My failures occur when I make anything bigger than proofing batches. I'm often using improvised HNO3 or none et al. Plus I dont really have enough space to work in privacy with anything that takes more than an hour or two. Hexamine isnt a shelf item where I am, so after mailordering, it costs substantially more than aspirin and I actually DO use it for fuel.
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Ral123
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[*] posted on 2-6-2012 at 03:01


My hexamine is kinda cheap as I pretend and I still don't use it for fuel (only once when I was very sick and was out of gas and need warm water for a medicine). And man don't underestimate your HNO3. I did kinda redneck synth and the HNO3 yielded quite a lot of rdx.
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[*] posted on 15-6-2013 at 22:03


Related thread
www.sciencemadness.org/talk/viewthread.php?tid=24624

.
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[*] posted on 16-6-2015 at 13:05
Your emergency preparations


I'd like to know how you guys prepare for such an event, with any nitration.

Lets imagine you notice a runaway has started, heat rises fast, smoke ect.

Adding water to the mix will create additional heat, maybe causing detonation in that very moment...?

I use a cooling vessel that is large enough to push over the beaker in there, thus drowning everything quickly in the ice bath.
This could be done with a stick or something, so one does not have to touch the beaker during cook-off...


How does your strategy look like, did I forget something?

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[*] posted on 16-6-2015 at 13:43


I have no experience nitrating to make explosives. But I have had runaways while oxidizing alcohol with nitric acid. My strategy to avoid them now is as follows:

1. Bring the fuel up to the temperature where it will vigorously react with the nitric acid. This is usually ~60°C. Keep it hot and stirred.

2. Add the nitric acid a few drops at a time. Only add more once the reaction has subsided.

This has worked well, the reaction always being under control.

[Edited on 16-6-2015 by Magpie]

[Edited on 17-6-2015 by Magpie]




The single most important condition for a successful synthesis is good mixing - Nicodem
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BromicAcid
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[*] posted on 16-6-2015 at 13:55


Quote: Originally posted by rollercoaster158  
Never pour a runaway nitration mixture into water! The sulfuric acid will heat up vigorously with the water and drive your runaway further.

H2SO4 + H2O = HSO4- + H3O+


You add enough water to act as a heat sink and that would not be a problem, you dilute the reaction mixture enough and your nitration will essentially come to a dead stop. If you were running an aromatic nitration as soon as you started chucking water in there you're no longer going to be favoring NO<sub>2</sub><sup>+</sup> formation and your nitration will significantly slow and even though nitronium ions are not necessary for a non-aromatic nitration (as far as I know) you do like to have something to drive them forward like sulfuric acid to pull off the water, once that is diluted then the reaction should stop as well. So really, the extra heat of hydration for putting in extra water is not going to be a disaster (except any spray you might get).

Really, you wern't stirring, your heat transfer went to crap, your local reaction temperature started to climb, your reaction ran away. I've had runaway reactions but amusingly enough never a nitration. Runaway Fenton's reagent was a hoot, runaway acetone peroxide was da-bomb, but runaway oxidation of KBr with KBrO<sub>3</sub> and H<sub>2</sub>O<sub>2</sub> was the most spectacular. Although the sodium hexametaphosphate reduction to phosphorus that went up all at once like thermite certainly earned its string of cuss words.




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[*] posted on 16-6-2015 at 16:11


Quote: Originally posted by BromicAcid  
Although the sodium hexametaphosphate reduction to phosphorus that went up all at once like thermite certainly earned its string of cuss words.
You did this? It's on my list. But I need to build a furnace first. Do you have details posted anywhere? I was going to follow the lead of Rogereymaw demonstrated on his youtube clip. But I was going to don a bit more safety gear -- ie, not wear shorts and not poke it nonchalantly with a stick.
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[*] posted on 18-6-2015 at 01:58


Well,in NG synthesis there is an ice slush sink if the temp rises moderatly.
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[*] posted on 18-6-2015 at 20:38


Quote: Originally posted by kecskesajt  
Well,in NG synthesis there is an ice slush sink if the temp rises moderatly.
Ice bath?
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[*] posted on 19-6-2015 at 01:36


Quote: Originally posted by Hawkguy  
Quote: Originally posted by kecskesajt  
Well,in NG synthesis there is an ice slush sink if the temp rises moderatly.
Ice bath?

Almost.It was not cooled by ice bat,just cooling water that was flowing every time in the syntesis.
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