Sciencemadness Discussion Board

Optimum temp for nitration of ETN ?

underground - 4-12-2015 at 15:46

What is the best temp for nitration of ETN ? I have seen some people go at 5-7°C. Other close to 15°C. At some patents up to 45°C. Also what the temp must be when we add the nitrate salt (AN,KNO3,NaNo3 e.t.c.) into H2SO4 ? How much the temp affect the final yields ?

[Edited on 4-12-2015 by underground]

TheAlchemistPirate - 4-12-2015 at 19:03

Finally a thread relevant to what I have worked on recently...
In my experiments the most etn forms at the highest possible temperature, and the longer nitration periods. That means if you can keep your nitration solution at 20 C without a runaway, go for it. With lower temperatures such as 10 C,I get very poor yields. This is when it reacts for 25 minutes. It seems that temperature very much affects yields in this reaction.
When adding the nitrate salt to the H2SO4, I keep it below 20 C, and add the nitrate salt slowly of course. After the addition of the nitrate salt is complete, I bring the mixed acids to room temperature and stir. If this causes the solution to heat rapidly, I place it back into the ice bath and repeat until the temperature only rises gently. I believe this ensure that all the reagents in the mixed acids are reacted, which seems to be very important.
As far as the nitration, I bring the solution to 15 C and begin adding the erythritol. As the erythritol is added in portions, the temperature is alternately brought between 15 and 20 C,to ensure the reaction is actually taking place. After the erythritol addition is complete, I bring the solution to 20 C and monitor the reaction at that temperature for 25-30 minutes. This had a 50% yield. (put in 7 grams erythritol, got 7 grams erythritol tetranitrate) I will try this again with a 1 hour nitration period, which I believe should give a better yield.

Gargamel - 5-12-2015 at 02:37

I would expect ETN to have a high chance of nasty explosions in case of a runaway.

My last batch was done at 5° C and the yield was about 1g ETN per 1g erythritol.

At 20°C I got about 1,2 - 1,3g


It seems like the reaction stops at some point. Some PETN reports mention heating the batch after the reaction has died down...

When doing this I've had good yields but also constant reddish clouds under crazy stirring. I'm very afraid doing this with ETN.

[Edited on 5-12-2015 by Gargamel]

NeonPulse - 5-12-2015 at 02:46

I have kept the temperature of my ETN batches to around 20-25c through out the process.although once something very briefly needed my attention and the temp got as high as 36c without incident. Rapid stirring controlled the reaction so I suspect that there is quite some leeway from temperatures that cause a runaway. This temp 20-25c makes for a much smoother and complete nitration by not allowing the unnitrated polyol to gather up,preventing a runaway reaction.
This is for mixed acids though. I'm not too sure if a nitrate salt mixture would be OK or not since it is much thicker making the temp harder to regulate. Too cold and a runaway may well happen since the erythritol nitrates too slowly and builds up so when the temp gets too high the build up begins to nitrate too fast causing problems. About a half hour after the last addition is good enough for a 10-15 g batch and in my experience the method scales up ok if 70% nitric is used.

underground - 5-12-2015 at 03:19

When i add a nitrate salt to H2SO4, some nasty fumes comes out. From were these fumes comes ? Is it because nitric acid evaporates ? But the boiling temp of nitric acid is close to 80°C

ecos - 5-12-2015 at 03:46

Quote: Originally posted by underground  
What is the best temp for nitration of ETN ? I have seen some people go at 5-7°C. Other close to 15°C. At some patents up to 45°C. Also what the temp must be when we add the nitrate salt (AN,KNO3,NaNo3 e.t.c.) into H2SO4 ? How much the temp affect the final yields ?

[Edited on 4-12-2015 by underground]


can you please provide me with the patents since I am interested.

underground - 5-12-2015 at 04:17

Quote: Originally posted by ecos  
Quote: Originally posted by underground  
What is the best temp for nitration of ETN ? I have seen some people go at 5-7°C. Other close to 15°C. At some patents up to 45°C. Also what the temp must be when we add the nitrate salt (AN,KNO3,NaNo3 e.t.c.) into H2SO4 ? How much the temp affect the final yields ?

[Edited on 4-12-2015 by underground]


can you please provide me with the patents since I am interested.


http://www.wydawnictwa.ipo.waw.pl/cejem/vol-10-03-2013/Kunze...

Gargamel - 5-12-2015 at 05:28

@underground:
cool your acid before you add the nitrate, add it slowly and stirr while you do it.
Thus you prevent your acid from decomposing.




TheAlchemistPirate - 5-12-2015 at 11:35

H2SO4 reacting with a nitrate salt to form HNO3 is an exothermic reaction, similar to a runaway reaction. If the temperature gets way too high and the nitric acid starts decomposing, red fumes of nitrogen dioxide are given off. If white fuming nitric acid (formed when you add H2SO4 to a nitrate salt) contacts airi above about 10 C, it evaporates(fumes) and a choking white mist comes out. This isn't decomposition however.

ecos - 5-12-2015 at 12:43

Quote: Originally posted by underground  
Quote: Originally posted by ecos  
Quote: Originally posted by underground  
What is the best temp for nitration of ETN ? I have seen some people go at 5-7°C. Other close to 15°C. At some patents up to 45°C. Also what the temp must be when we add the nitrate salt (AN,KNO3,NaNo3 e.t.c.) into H2SO4 ? How much the temp affect the final yields ?

[Edited on 4-12-2015 by underground]


can you please provide me with the patents since I am interested.


http://www.wydawnictwa.ipo.waw.pl/cejem/vol-10-03-2013/Kunze...


Thanks dear for the reply but this is not a patent :)

underground - 5-12-2015 at 12:57

Quote: Originally posted by ecos  

Thanks dear for the reply but this is not a patent :)


Yea you have right, i did not notice that.

[Edited on 5-12-2015 by underground]