Sciencemadness Discussion Board

Series of ETN nitration problems

underground - 27-5-2018 at 08:01

Lately i am encountering lots of problems trying to make some ETN. I did not have any issues in the past. My used to yields was about 50-60% which is ok for ETN and i was still satisfied with it, but lately i can not make any ETN at all. I was using H2SO4/AN. (100ml H2SO4, 50g AN or 65g kno3, 15g E)


I had some h2so4 left over from the past and i did tried to nitrate some. I did got some ETN maybe like 30-40% yields which is ok using kno3. i used kno3 cause i got some problems with AN. AN did not dissolved for some reason into H2SO4,and after nitration, when i crashed it into a water, the salt was there, i had to squeeze with my fingers in order to be dissolved into water, but was not like that before nitration. AN was recrystallized from fertilizer and that it what i used before with no problems at all. I was thinking that AN now contains some stuff that prevents nitration. After that i did not tried with AN again and i moved to kno3. Erythritol, kno3 and AN are always stored into a desiccator bag. My h2so4 usually comes from concentrating battery acid to azeotrope.

After those 2 nitration (1st failed with AN and the 2nd with kno3) i was out of H2SO4 so i would have to make some more. When i got some new H2SO4 i tried again with Kno3 2 times and i got 0 yields. I thought that my H2SO4 was the problem, i thought that i did not boiled it enough, so i boiled it more to be sure that it was concentrated. (Ofc everything done with proper safety and safety equipment.) After the 2nd concentration i tried again and i got 0 yields again. I have tried it with various temperatures too (from 10 to 40) with 0 yields always.

Some notes: When i am using kno3, almost at the end of the nitration, after adding my E, some N02 gas comes out, that was happened even at the 1st time i tried with kno3 when i did got some ETN. That was not happened with AN.

After the addition of kno3 the mixture does not look so strong as it did not fumed that much (fuming nitric acid), while in the past it did.

I have my E for like 4-5 years now, is it an issue? (i think not cause i did got some ETN with the 1st nitration)

It looks like the new H2SO4 is the problem right ? but i really dunno why. I can not see any reason why it does not working any more while in the past it did with no problems at all.

Also why AN does not dissolved into H2SO4 while in the past it was ok ?

Sorry for the big post but i really want to explain what is going on here.

joseph6355 - 29-5-2018 at 20:46

Are you sure that you have ammonium nitrate instead of that calcium-ammonium nitrate fertilizer?
https://en.wikipedia.org/wiki/Calcium_ammonium_nitrate

Regarding the NO2 gases, is your temperature closely monitored? Are you using efficient stirring to prevent hot spots? ETN nitration carried by nitrate/H2SO4 process can form a very thick slurry, which would increase the chances of a runaway or hot spot formations. Thats why I'd rather nitrate ETN with Nitric Acid instead of a nitrating salt.
I leave the nitrating salts for picric acid. :P

Anyway, you could make 2 separate solutions, one for the ETN sulfates and other for the nitrating salt/H2SO4, and then you add the latter to the ETN sulfate one. This would allow your nitrate salt solution to be warmed in a hotplate, helping it to dissolve, just dont let it get too hot or nitric acid might boil away.

underground - 30-5-2018 at 11:28

I have tried it before and dissolving erythritol into h2so4 dropped my yields.

According to calcium-ammonium nitrate fertilizer maybe you have right. Is there any way to check if your AN contains calcium nitrate ? I checked the solubility of CaNO3 and it is almost the same as AN and it is like the same hygroscopic too.

joseph6355 - 30-5-2018 at 22:47

Quote: Originally posted by underground  
I have tried it before and dissolving erythritol into h2so4 dropped my yields.

According to calcium-ammonium nitrate fertilizer maybe you have right. Is there any way to check if your AN contains calcium nitrate ? I checked the solubility of CaNO3 and it is almost the same as AN and it is like the same hygroscopic too.

What was the concentration of your H2SO4? Higher concentrations will lead to the decomposition of Erythritol. I would keep my acid at a 90ish % concentration. And pay attention to temperature.

I don't know any reliable way to determine if you have the double salt or not.
What is the source of your nitrate?


Attachment: US1691954A.pdf (98kB)
This file has been downloaded 127 times



[Edited on 31/5/18 by joseph6355]

underground - 31-5-2018 at 12:04

Usually i am using AN but it looks it contains calcium too. I will have some fresh Kno3 tomorrow and i will try again. My h2so4 is azeotropic (98%)

Laboratory of Liptakov - 31-5-2018 at 13:12

On amateur field is usually, that the way is a target. Now come times, when will necessary use distillation device. I know, that is difficult way, but ice packs are intentionally contamined. And maybe not only CaNO3.

XeonTheMGPony - 1-6-2018 at 03:50

take your ammonium nitrate, calcium nitrate mix, disolve in clean strong amonia water, filter all the crap out, then enjoy the head ache that it is to dry it with out a vacuum system! = pure AN

joseph6355 - 1-6-2018 at 08:23

Quote: Originally posted by underground  
Usually i am using AN but it looks it contains calcium too. I will have some fresh Kno3 tomorrow and i will try again. My h2so4 is azeotropic (98%)

You should dilute it with water until 90% concentration is achieved.

LearnedAmateur - 1-6-2018 at 09:15

Would it be possible to throw in some sodium carbonate for a metathesis reaction? Calcium carbonate should drop out as a white precipitate as a definitive test, no? Plus, you can measure the amount of precipitate produced, pegged against the sample mass used, to figure out the concentration.

underground - 1-6-2018 at 13:19

AN will react too relising ammonia.

Quote: Originally posted by XeonTheMGPony  
take your ammonium nitrate, calcium nitrate mix, disolve in clean strong amonia water, filter all the crap out, then enjoy the head ache that it is to dry it with out a vacuum system! = pure AN


I do not have ammonia water. I will try with kno3 and i will let you know

underground - 2-6-2018 at 10:47

I did try with some fresh kno3. Reaction was looking better as the Nitric acid started to fume from the first additions of kno3 indicating concentrated mixed acid. Unfortunately i did have 0 yields again :( I really dunno what is going on. I think the problem is the H2SO4 because i did got some ETN from my last old H2SO4. Another thing i am thinking is my old Erythritol, i got it for 4-5 years, but as i said before, i got some ETN. If Erythritol would be the problem i would not get any ETN at first right ?

Rocinante - 2-6-2018 at 12:44

both need to be very dry and it's important to rise the temperature to about 20°C for 1 hour at the end of the nitration (2 h total), otherwise it tends (the KNO3 route) to produce water soluble trinitrate (and lower nitrates)

underground - 2-6-2018 at 14:24

All salts are into a desiccator bag with cacl. I was doing the nitration at 35°C

I think that this is not an issue as long as i have seen patents making ETN at 40-60°C

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&...

I will give it a try tho not over 20°C, but i don't think it will change anything.

Laboratory of Liptakov - 2-6-2018 at 21:47

You can try hold temperature at 4 - 6 C during addition of Erythritol. Mixing 30 minute at 6 C. And after increase tepm. on 20 C on 30 minute. We are everybody only disciples. For attempt I recommend only 2,5 g E.

underground - 3-6-2018 at 09:29

Laboratory of Liptakov thanks a lot! I tried a small batch (50ml SA/30g Kno3/7,5g E) holding the temp below 10 C during addition of Erythritol. I let it for about 30-40 min after the addition of Erythritol. I did got some ETN at last. Yields dont look that much, maybe 4-5g recrystallized , they are drying right now. Maybe if i would let it 30 min more i would take some more BUT at least i got something. It looks like high temp destroy the E while you adding it into a mixed acid. I guess after 30 min from the last add of E you can increase the temp more cause there is mostly low nitrated E. I believe low nitrated E is not that much sensitive to temperature as pure E is.

Rocinante - 3-6-2018 at 11:28

~ 30 % yield or 5 g of ETN from 7.5 g of erythritol is about as good yield as ur gonna get (via the KNO3 route). Not bad, since producing 100 g of ETN will take only 1 l of acid, 600 g of KNO3 and 150 g of erythritol and 1-2 l of EtOH + some baking soda, so you're looking at about 35 $/100 g of ETN which isn't bad at all.

underground - 3-6-2018 at 11:59

A bit expensive, isnt it ?

Rocinante - 3-6-2018 at 12:13

That's enugh for 70 - 100 blasting caps or 4 hard core PBX charges, not bad for 35 $ (if u live in the US).

Laboratory of Liptakov - 3-6-2018 at 13:38

It's nice, Underground. As a next step, I propose this attempt. Reagents: E = very fine and very dry 5g. KNO3 very gentle and very dry 20g. SA 95-98% 33ml. Procedure: Cool SA on - 10C. Add E in small parts (5x1g) . Keep the temperature below + 5 ° C. Dissolve all E in acid. Add KNO3 in small portions of 5 x 4g. Keep the temperature below + 5 ° C during addition. Stir for 10 minutes at + 5 ° C. Increase temperature to + 10 ° C (10 minutes) Increase temperature to + 20 ° C (30 min). Following is the usual process, pour into cold water and so on. We are all just disciples: But we can learn from observation. And also from patents. It's just a suggestion. Maybe it will not work......:cool:

underground - 3-6-2018 at 13:50

I have tryed in the past dissolving E into SA and i got low yields. Other members here in this forum got the same bad yields with this method too. But maybe i will try again, :D

Laboratory of Liptakov - 3-6-2018 at 13:54

https://en.wikipedia.org/wiki/Erythritol_tetranitrate
............Increase temperature on + 20 C on 60 minute...........
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.653...

[Edited on 3-6-2018 by Laboratory of Liptakov]

underground - 3-6-2018 at 14:30

From what you linked:

"The erythritol/sulfuric acid mixture was added
to the nitric/sulfuric acid mixture over 30 minutes while maintaining the temperature below
10 C. After addition was complete, the mixture was warmed to 35 C and stirred for 1 hour."

And from Wiki

"It is important to perform the last step at about 20°C - for about an hour in the case of KNO3/sulfuric route. Lower final temperature is going to yield only the trinitrate and lower esters and these are soluble in water"


So it looks like it works like this:

1st you add your E at low temp so it wont decomp from the mixed acids. E into mixed acids at low temp produce lower esters. Next, you need to increase the temp in order to fully nitrate the lower esters. Obliously low nitrated esters are not so sensitive as pure E as i said. On your pdf it is said as high as 35 C.



P.S.

From wiki: "Ammonium nitrate is superior in terms of yields and ease of manufacture."

I can see the reason why AN is easier to work with vs kno3 but i really dont see the reason why you could get better yields.

[Edited on 3-6-2018 by underground]

Rocinante - 3-6-2018 at 14:42

These are all my wiki edits, based on experimentation and experience....

underground - 3-6-2018 at 15:13

I see. Maybe when i got time i will try few small batches at various temp, increasing the temp on every batch till I got the best yields. Also i was thinking to lower the amount of E cause the yields are always low (40-50%) I am sure much acid is wasted on lower nitrated esters, so reducing the ammount, you could have stronger acids to fully nitrate the E

Herr Haber - 3-6-2018 at 16:22

Quote: Originally posted by underground  

I did not have any issues in the past. My used to yields was about 50-60% which is ok for ETN and i was still satisfied with it,


You already had a problem back then. Your yields should be closer to 90%
That's with 96% H2SO4 and azeotropic HNO3 at least.

I have read here and there on the forum many poor ideas in the synthesis of ETN or others:
Adding Erythritol mixed with a nitrate salt in the cooled sulphuric acid was one that shocked me. Hotspots ! Decompositon of the product ---> Less yield.
Finishing the nitration at 40% and stop where fumes appear ?
Lost N, some product oxydized, NOX ---> Less yield

underground - 4-6-2018 at 06:12

Ok today i tried another small batch as i described above but this time i increase the temp to 35 C at the last 30 min. I did not got any yields. It looks like the safe temp, at least with this method, is somewhere between 20-35 C. I really have no idea how patents go up to some crazy temps like 40-60 C. I won't never again try to go above 20 C, i believe it doesnt worth. Next time i will try to scale it up to 200ml SA and see how it will work.

XeonTheMGPony - 4-6-2018 at 19:17

you really need to distill the acid, I had superior results with care fully distilled H2SO4. this eliminates a huge variable!

Laboratory of Liptakov - 4-6-2018 at 21:17

I have same opinion as Xeon. Undeground, You need distillation assembly. For SA and for NA. And for 100 next procedures. Both are basic compound of all researcher. Testing different temperatures are the blind way. In this problem of low yields.

XeonTheMGPony - 6-6-2018 at 04:14

Yup just no getting around some basic core glass wear, where not having it is actually dangerous to you and others.

I even care fully distill my acetone even for use as a solvent and I have found large amounts of crap after wards at time.

You need to remove variables and drain cleaner sulfuric is a big one.

Next what was the original source of the Erythritol? If pure it will be good.

underground - 6-6-2018 at 05:16

I can see your points Laboratory and Xeon but i really want to keep things as much simple as possible. Anyway i did another nitratation and the yields really shocked me, maybe i got close to 80-90%, they are still drying, i can tell you precisely after it will be completely dry. I used 400gr H2SO4 (about 219ml 98%), 120gr Kno3, 21g E (I should have use 30g but i reduced the ammount to 21g thinking that i could reduce the lower nitrated esters and looks like it worked). The procedure was exactly as Laboratory said to me. Yields looking close to 40g recrystalized. :D

[Edited on 6-6-2018 by underground]

roXefeller - 6-6-2018 at 18:22

Quote: Originally posted by underground  
I can see your points Laboratory and Xeon but i really want to keep things as much simple as possible.


If you want simple, go with acetone peroxide. Explosives aren't something we enter into looking for the simplest routes. You wouldn't jump out of an airplane with a kite just because it was easy to buy and parachutes were sold out. Get the tools, glassware, and the reagents that are necessary before jumping out the door. ETN was the very compound that started the "Life after detonation" thread.

And why are you scaling up your reaction when you're still working out the parameters?

underground - 7-6-2018 at 12:01

Quote: Originally posted by roXefeller  

If you want simple, go with acetone peroxide. Explosives aren't something we enter into looking for the simplest routes. You wouldn't jump out of an airplane with a kite just because it was easy to buy and parachutes were sold out. Get the tools, glassware, and the reagents that are necessary before jumping out the door. ETN was the very compound that started the "Life after detonation" thread.

And why are you scaling up your reaction when you're still working out the parameters?


Actually, the place where I am working does not have electricity and i cant bring electricity there too. Even if i bought the equipment i could not work with it.

Now i am scaling my reactions up cause yields are very good already and i did not have much ETN left over. Also i have plenty of reagents so I don't mind to scale it up a bit.

Laboratory of Liptakov - 8-6-2018 at 06:52

Haha....Parachutes were sold out... But : Explosives aren't something we enter into looking for the simplest routes. Truth,. Next: High yields?
Erythritol were dissolved in H2SO4 ? Works it ? Low temperature were used ? I am glad to hear it.....:-)....:cool:

Erythritol Temp and How long it lasts

TGT - 23-12-2018 at 00:59

I have been experimenting for the last couple years on and off with ETN and I find the most productive way is to mix the acids first, then finally add the dry ground Erythritol. I let the temp get to around 25 degrees C. and nitrate for 30 minutes to 45 minutes with constant swirling. I found the higher temperatures do not reduce productivity efficiency. It seems to produce 140% (usually, or very close) yield before purifying. After purification the yield is a little over 75%, usually, sometimes greater. I rinse with sodium bicarbonate and water through the coffee filter and let dry. Then purify with Methyl Alcohol and pour the entire hot solution directly into a coffee filter and let drain into water again mixed with Sodium BiCarbonate. Let this sit at room temp, then place in fridge for 12 hours, re-filter and dry.

I have noticed even after deacidifying and washing numerous times and storing, the ETN turns to the tri-nitrate in about 1 year and a half, kept in a fridge and sealed well. The last day it exploded fully was around 16 months and on the 18th month it didn't do anything but fizzle. This was tested only with putting a small match head amount between aluminum foil and lighting with a torch. When at the 18th month it did not go off, I mixed a small portion of the degraded ETN into cold water and it dissolves. This makes me believe it lost some nitrogen and was not the tri-nitrate. I could be wrong, any help would be greatly appreciated.

I am a little disappointed that it does not have a better shelf life, although a year and a half is pretty good I guess. Anyone have any ideas to make it last longer? I was thinking of letting it sit in Ammonia water for an hour or so after my normal deacidification process. On the other hand, my Picric Acid lasts indefinitely, which I am very happy about.

TGT

hissingnoise - 23-12-2018 at 03:54

It sounds like your ETN had a pH that was off neutral ─ the final wash should be with a large volume of tepid water of strictly neutral pH...

Washing is something that can't be overdone.

My suspect would be slow alkaline hydrolysis?


TGT - 23-12-2018 at 17:32

Thank you for the info! I will try what you say, unfortunately I won't know for another year and a half, but what you say does make sense. I don't believe I ever washed with just neutral PH water. My final wash was always with water mixed with sodium bicarbonate. I did not think the sodium bicarbonate would pose a problem as long as it was no longer acidic. I guess that is where I made my mistake? I am making a batch tonight, so hopefully I can get a batch that lasts indefinitely - or at least close, that is my goal. I would like to make quite a lot, then not have to make it for a few years or more. Thanks again!

TGT

hissingnoise - 24-12-2018 at 03:45

Quote:
I did not think the sodium bicarbonate would pose a problem as long as it was no longer acidic.

Bicarb. contamination is your culprit.

Its slow decomp.; 2NaHCO3 → Na2CO3 + CO2 + H2O significantly raises pH over time...

I've always used freshly distilled water (tap-water is full of shit) for the final wash ─ if left to stand its pH drops as CO2 absorbs and heating is required to bring pH back up to neutral.

Sobrero, early on, noted that NGl stored for 10 years gave an analysis close to the theoretical ─ and indeed most if not all organic nitrates may be stored indefinitely in the pure state.