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Fantasma4500
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i did however hear from somewhere that KNO3 happens to yield the best results with this exact synthesis
also did see a few posting that KNO3 should yield the best on this forum
i would understand the logic in that the mixture is more liquid'ish and it doesnt block itself in the already very thick sludge of K2SO4
i could ask the guy to try out NaNO3 which he happens to have some laying around, hes had terrible yields in which upped abit when he tried KNO3
rather than 62% HNO3 or NH4NO3
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NeonPulse
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Quote: Originally posted by Antiswat  |
i did however hear from somewhere that KNO3 happens to yield the best results with this exact synthesis
also did see a few posting that KNO3 should yield the best on this forum
i would understand the logic in that the mixture is more liquid'ish and it doesnt block itself in the already very thick sludge of K2SO4
i could ask the guy to try out NaNO3 which he happens to have some laying around, hes had terrible yields in which upped abit when he tried KNO3
rather than 62% HNO3 or NH4NO3 |
I actually get pretty decent yeilds also using KNO3 over NH4NO3 it also
seems that the bigger the synth with the AN the worse the yeilds. KNO3 has worked very well for me with this type of synth although it gets pretty
tough to stir. HNO3 so far has given the best yeilds (as expected)i am yet to try to have the temp higher with the AN process but i am going to give
it a try i see that can improve results.
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Chill
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| Quote: Originally posted by NeonPulse | | Quote: Originally posted by Antiswat |
i did however hear from somewhere that KNO3 happens to yield the best results with this exact synthesis
also did see a few posting that KNO3 should yield the best on this forum
i would understand the logic in that the mixture is more liquid'ish and it doesnt block itself in the already very thick sludge of K2SO4
i could ask the guy to try out NaNO3 which he happens to have some laying around, hes had terrible yields in which upped abit when he tried KNO3
rather than 62% HNO3 or NH4NO3 |
I actually get pretty decent yeilds also using KNO3 over NH4NO3 it also
seems that the bigger the synth with the AN the worse the yeilds. KNO3 has worked very well for me with this type of synth although it gets pretty
tough to stir. HNO3 so far has given the best yeilds (as expected)i am yet to try to have the temp higher with the AN process but i am going to give
it a try i see that can improve results. |
It might not be the AN that makes larger synths have low yields. As far as I've read, the ETN making processes DOES NOT scale well.
If you used 15/60/100 and got a good yield, you may not get a good yield by tripling the reagents to 45/180/300. Common sense would tell you that the
synth would result in around x3 yield, but that's not the case.
You'd have to experiment to find what works best, but like I said, ETN synthesis doesn't scale. (Or so I've read from people on the forum)
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Intergalactic_Captain
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Don't want to start a new thread, so with the discussion of reagent quality I figure this fits in here...
I'm not sure anyone has brought up the idea of sourcing erythritol from artificial sweeteners - In this case I mean those based on stevia. At work
tonight, I managed to snag a couple boxes of a new product that's about to be released for sale - And the way we do things, I guarantee you it's a
near-identical knockoff of the name-brands...
That said, it can be assumed that stevia-based artificial sweeteners are 50-98% erythritol (couldn't say without the batch-mixing orders), the
remainder being "flavorings"...
So, my thought is that although not nearly economical, it may be worthwhile to experiment with for those that cannot find raw erythritol over the
counter, while fake sugar packets are literally everywhere... My only curiosity on the matter would be whether it would be more feasible to attempt
to recrystalize the erythritol beforehand or nitrate the unknown mixture and purify the product from there - My gut feeling is that it would be more
prone to runaway, but a simpler purification afterwards than beforehand...
If you see me running, try to keep up.
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Motherload
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I wouldn't be using that brand of erythritol if it could be less than 98%.
Especially since the pure stuff is available online.
Also consider .... If your KNO3 isn't pure .... It's most likely just gonna have some other nitrates or sulphates etc mixed in which are not going to
interfere with the reaction.
On the other hand if you had some unknown nitrate-able sugar mixed in with the Erythritol .... Now you could have problems .... Any where from
temperature sensitive runaways to separation of the final product being a pain.
"Chance favours the prepared mind"
"Fuck It !! We'll do it live !!"
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Xfactor
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I made a video on synthesizing ETN with nitric, sulfuric acid and erythritol.
What do you think?
So far I know that I should not have used a thermometer to stir and that I should have added more info on the recrystallization (methanol at 50C)
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Chill
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| Quote: Originally posted by Motherload | I wouldn't be using that brand of erythritol if it could be less than 98%.
Especially since the pure stuff is available online.
Also consider .... If your KNO3 isn't pure .... It's most likely just gonna have some other nitrates or sulphates etc mixed in which are not going to
interfere with the reaction.
On the other hand if you had some unknown nitrate-able sugar mixed in with the Erythritol .... Now you could have problems .... Any where from
temperature sensitive runaways to separation of the final product being a pain. |
This got me thinking about the purity of my erythritol. I believe it's pure, even though I get it as sugar substitute. The actual product is just
named "Erythritol" and claims "100% pure" on the packaging. Ingredient list on the back only states "Pure Erythritol Crystalline Powder".
If you want to check it out for your self, google "Now Real Food Erythritol". I still don't know what could've went wrong with my first synth, and
I've yet to try again. I'll try again this weekend.
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nux vomica
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I have used the little packets of sweetener you get from the supermarket containing erythritol and get same yealds as posted I use drain cleaner and
ammonium nitrate as the nitration mix the sweetener packets must be almost pure erythritol.
nux
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Chill
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Bollucks, I tried the synth again and got the same results (kinda). Just to preface this long note, I'd like to reiterate a few parts of my procedure.
I used 25ml more sulfuric acid this time to help dissolve the nitrate. After cooling my acid down to 10 degrees Celsius, I added my recrystallized
potassium nitrate and stirred. Just like before, I was left with a cloudy acid mixture that emitted white fumes, and hard almost rock solid lumps of
what I can only assume is potassium sulfate. That's what it's supposed to be, right?
Sulfuric acid+Potassium Nitrate ----> Nitric acid+Potassium sulfate
Isn't that how it works? anyways, the sulfate was very hard, almost like a rock! I proceeded with the experiment.
After an hour of nitrating, I sampled the concoction by pipetting a few ml into a test tube of cold water. I saw (what I definitely thought was)
precipitation. Huzzah! The precipitate was insoluble in the water, and just to make sure that it could be ETN, I filled the rest of the test tube up
with methanol. Sure enough, the precipitate had dissolved and I was left with a greyish solution.
I was convinced I had ETN, so I decided to crash my entire beaker into double it's volume in cold distilled water. I saw a little bit of precipitation
as I was taking my time pouring. For whatever reason, I finish the crash and all that is out of solution are the rock like clumps that I began with. I
filtered the (potassium sulfate?) clumps out and was left with a pretty clear liquid. No ETN?!
The weird thing is, for those hard rocks to be K2SO4, it would be extremely soluble in water, but they're not. So what are they? This is absolutely
bonkers. How could the clumps that formed when adding the KNO3 to H2SO4 at the beginning of the experiment be the only thing out of solution once the
procedure was done? And further more, WHAT are they?
Does anyone have an explanation for what happened? I swear I had some ETN by the results of my test, but I ended up getting shafted.
If anyone needs a more verbose or clear understanding and what happened, let me know. I really want to get to the bottom of this.
[Edited on 10/14/2013 by Chill]
[Edited on 10/14/2013 by Chill]
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hyfalcon
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I would just use an excess of KNO3 and H2SO4. Make sure all of your reagents are as finely ground as you can get
them. Good stirring is a must.
[Edited on 14-10-2013 by hyfalcon]
[Edited on 14-10-2013 by hyfalcon]
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Chill
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| Quote: Originally posted by hyfalcon | I would just use an excess of KNO3 and H2SO4. Make sure all of your reagents are as finely ground as you can get
them. Good stirring is a must.
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This doesn't answer any of my questions 
What are the clumps that are left over? What was in my test tube that wasn't soluble in water, but soluble in methanol?
If anything, I should use an extreme excess of H2SO4 to dissolve (assume that it even will dissolve) those clumps that I had in the beginning. I've
seen videos of people making ETN and they don't have the clump problem, so i'm really confused.
I've played around with the sulfuric acid and nitrate some more and determined that if heated, the clumps dissolve, but as soon as the H2SO4 is
chilled (like you're supposed to in ETN synth) the clumps form again as whatever they are made of comes out of solution.
EDIT:
Well, i'm convinced the clumps could be K2SO4 (or KHSO4) after I ran some tests and did some math. Since my concoction was so heavily diluted with
water after last nights crashing, I was able to boil a small sample of the (mostly water) solution and was left with some solid heavily resembling the
rock hard chunks mentioned previously. Obviously the solid had to be soluble in water/H2SO4 (which K2SO4 is). I also massed the Clumps that I filtered
out and did some math and everything looks like it should. Without going into too much detail on the math stuff, I compared the approximate volume of
water I used for crashing, and potassium sulfates solubility in water and ended up with a number only a few grams off from the measured mass of my
clumps.
Anyways, The problem still remains about my apparent precipitation that turned out bunk when I crashed my entire nitration mix. The nitration mix was
very milky colored, as it should be, and when I dropped a few mL into the test tube of cold water, there was definitely a significant amount of solid
at the bottom which also turned out to be soluble in methanol. I'm pretty damn sure this was ETN. I figured out that K2SO4 wouldn't be that soluble
(if at all) in methanol, so I don't think it's possible that I had just pipetted K2SO4.
I must say, this entire experience has left me with my brain in a knot. Where the heck could I have gone wrong?
[Edited on 10/14/2013 by Chill]
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underground
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Try some AN in case of KNO3 to see what is going to happen.
Also if you would like some ETN and not a big amount, try to produce some nitric acid from sulfuric acid and nitrate salt (kno3 in your case) by the
distillation process, and then use the distillated nitric acid to make your ETN, It would be surely much more better 
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Chill
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Unfortunately, I won't be able to get a good distillation apparatus until Christmas (if I eve decide to get one). I plan on buying an organic chem set
which should serve me excellently.
I suppose I'll try AN this weekend. I was really hoping someone who did the KNO3 method could chime in and let me know if what I saw was to be
expected or not.
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underground
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| Quote: Originally posted by Chill | Unfortunately, I won't be able to get a good distillation apparatus until Christmas (if I eve decide to get one). I plan on buying an organic chem set
which should serve me excellently.
I suppose I'll try AN this weekend. I was really hoping someone who did the KNO3 method could chime in and let me know if what I saw was to be
expected or not. |
Try to distill some nitric acid with to bottles connected together with Teflon. In the one bottle add the kno3/h2so4 mixture and the other bottle try
to kip it cool by dipping it into an ice bath or whatever you can imagine
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Chill
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I suppose I could do that if I really needed nitric, but I really shouldn't. KNO3 should work, but it just won't for me. If the AN method turns out
bunk, I suppose that means there is a problem with something else (not my choice of nitrate). I'm going to wait until I get results on the AN method
before I think about trying to make nitric.
Thanks for the idea though, I'll keep it in mind.
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underground
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Try to make some HNO3 from H2SO4/ KNO3
KNO3 + H2SO4 -> HNO3 + KHSO4
You are going to need 1mole of kno3 (101.1gr) and 1mole of H2SO4 (98.1gr)
Mix well both of them and then let it to react overnight.
At the next day you are going to have some HNO3 and K2SO4
Place a funnel into a bottle, and into the funnel place a coffee filter.
Put the mixture into the funnel and collect the pretty pure HNO3
[Edited on 21-10-2013 by underground]
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Pyrotrons
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Has anyone experienced "freezing" of Ammonium Nitrate on the sides of their beakers during a synthesis? I've destroyed quite a good quantity of
reagents at this point... this has happened to me three times, and seems to happen randomly. When it occurs, it has always resulted in zero yield of
ETN. I remember doing two things to try and get the precipitated NH4NO3 back into solution, neither of which has ever worked. They are 1). Allowing
the temperature to rise 30C and 2). Adding an excess of H2SO4.
I speculate that the thermal properties of my setup are possibly TOO good. Could very cold temperatures (near 0C) at the reaction beaker sides be
reducing the NH4NO3's solubility within the mixed acids, causing it to precipitate out?
NOTE: I HAVE scaled this up from the original numbers, by a factor of about three IIRC.
The synthesis I use:
1). 240 grams of Ammonium Nitrate is slowly added to 175 mL Conc. Sulfuric Acid while keeping
the temp below 25 Celsius. (Note: I use a LOT of ice around the reaction beaker sides and bottom, with only a little water to fill.)
2). 75 grams of Erythritol is slowly added to the acid/nitrate mix while keeping the temp
10-15. This is stirred vigorously.
3). While still keeping the temp between 10 and 15 degrees Celsius, 330 mL Sulfuric Acid
is added while stirring vigorously
4). This is allowed to react for 30 minutes, then crashed into 4 liters of ice water and
filtered
(IF the synth works, I then recrystallize the ETN via Ethanol)
[Edited on 22-10-2013 by Pyrotrons]
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Chill
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Yeah, definitely sounds like you're having things coming out of solution. It shouldn't be ammonium nitrate though, it's ammonium sulfate.
(NH4)2SO4 has pretty good solubility at low temp (70.6 g/100 mL at 0c) which is why people suggest using
NH4NO3 over KNO3.
K2SO4 (the product of adding KNO3 to sulfuric acid H2SO4) is BARELY soluble (only 11.1g/100ml
at 20c!!!) , which is why I seem to be getting large amounts of those hard chunks of undissolved material.
I didn't suspect that they are the cause of my failed nitration, but you seem to think you've found a correlation between the presence of solids and
the yield of the nitration.
I don't know what to say other than try to replicate the experiment user "Swede" on this forum did. He put the absolute minimum amount of nitrate into
the mix so that there would be no sulfates out of solution. Personally, this is what I'm going to try if using ammonium nitrate doesn't work out for
me.
Here's a thought, not necessarily pertaining to the failure of our synths. I know we're supposed to use a large excess of acid in this synthesis, but
I never thought about how much. Using the ratio of reagents that you say you used, I calculated that you use almost exactly 2x the amount of acid as
the reaction calls for. I'm wondering if anyone can explain why there is such an excess of acid.
Here's a little bit of the math I did to come to this conclusion just in case anyone wants to confirm for themselves/double check my work:
Balanced reaction:
2NH4NO3 + H2SO4 ----> (NH4)2SO4 + 2HNO3
Conversions of amounts of reagents to moles:
240g NH4NO3 / 80.05g(MM) = 3mol NH4NO3
175mL (assuming 98%) H2SO4 * 1.83g/mL (Density) = 320.25g H2SO4
320.25g H2SO4 / 98.08g(MM) = 3.27mol H2SO4
According the the balanced equation, only 1 H2SO4 molecule is used in the reaction while there are 2 molecules of
NH4NO3 used. Using this information you can see that since the moles of each reagent are nearly the same, the excess of
H2SO4 is ~2x.
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Rosco Bodine
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The acid sulfate not the normal sulfate is the byproduct in this reaction scenario.
There are cases where the nitrate used does have a cation which corresponds with formation of the normal sulfate under the reaction conditions for
this nitration, but not for the ammonium or potassium or sodium cation, all of which nitrates will form the acid sulfate as the byproduct produced at
this low temperature range for the nitration.
Therefore your equation, although the stoichiometry works on paper just fine, is not in reality what occurs in the beaker.
To be precise what actually occurs, predominately is the following reaction
NH4NO3 + H2SO4 ---> NH4HSO4 + HNO3
However, there is another simultaneous and inevitable formation to some extent of nitrosylsulfuric acid which also is a nitrating agent, and how much
of it is present will depend upon the temperature and the level of H2O present in the reaction mixture. The nitrosylsulfuric acid is unstable and has
a decomposition trigger point that is aggravated by increasing moisture, and many "runaways" are actually the triggering of the decomposition of the
nitrosylsulfuric acid which hydrolyses to an oxidizing nitrous acid and a self-accellerating cascade or avalanche decomposition sets in which is the
runaway. Staying away from that inherent danger requires keeping the water content even in the completed nitration low enough so that the effect is
avoided.
Ignoring the effect or striving for too great of an acid usage economy brings danger to the nitration.
[Edited on 23-10-2013 by Rosco Bodine]
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Chill
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This explains so much for me, thank you for your response Rosco.
So you're actually just getting a bisulfate instead of a sulfate, interesting.
This is a really silly question, but I can't find any good solubility charts/tables for potassium or ammonium bisulfate. Would you happen to know
where I can get this information? My google-fu is weak.
There are a ton of ways for moisture to be introduced into the nitration mix, so the fact that the acid you mentioned is aggravated by moisture is a
little worrying.
As far as I know, the sulfuric acid is bound to contribute the most H2O to the mix since it's won't be 100% concentrated. The hygroscopic
nature of all the compounds involved would also increase moisture. I believe I've also read that when erythritol is added to the nitration mix,
H2O is a byproduct of one of the reactions that form ETN. Overall, there is quite a bit of moisture in the solution.
When you say "Ignoring the effect or striving for too great of an acid usage economy brings danger to the nitration.", do you mean trying to use the
least amount of acid possible in order to save on reagent use? I'm assuming this is because using an excess of sulfuric acid acts as a buffer between
the "safe zone" and runaway reaction?
[Edited on 10/24/2013 by Chill]
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Rosco Bodine
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Yes it is exactly true that striving for the greatest economy in the use of acid necessarily increases the relative water content in the starting and
especially in the completed or spent reaction mixture, and you need to take into account the water content increase that is the byproduct water from
the esterfication, as a percentage of the mixture of acids remaining at the completion of the nitration. If you start out with too little acid then
you have a more highly hydrated spent nitration acid that is unstable and the nitrated product is already present as fuel for the fire if
decomposition sets in due to the decomposition of nitrosylsulfuric acid which is self accellerating in avalanche once it begins. It is the same
effect as positive feedback in an amplifier circuit, so it is the opposite effect of regulation, meaning thermal runaway and once begun it cannot be
stopped except by quenching the entire mix and quick if there is even time for quick to get the job done. So the tipping point for runaway is to be
avoided by providing a calculated safety margin being mindful of the spent acid composition and allowing some extra margin for safety. Sunlight
aggravates the decomposition more than most people understand, and so does moisture and heat, and the effects of the three are synergistic, so it
isn't just arithmetic that applies more than generally to nitrations but ultimately it is algebra involving those three variables for sure and other
variables that can apply also, which must be taken into account.
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Chill
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You're very knowledgeable in this area, so I don't think it unwise to ask you what you think about my procedure.
I found it particularly strange that adding erythritol didn't increase the temperature, maybe I should've added it all at once. My second time around
I did it much quicker, but the result was the same. I used sugar substitute that you can google called "NOW foods erythritol". As far as I know, it's
pure erythritol, so I don't think anything was wrong with my reagents. The ratio I used was supposedly proven to work for multiple people.
I think the best way to see if I did anything wrong is to figure out specifically what other people have done to make them successful. For all I know,
stirring the mixture too vigorously screwed it up (although I don't think that was it).
If you've done it before, would you mind cross referencing my procedure with yours? If you don't see anything wrong, then perhaps give me an in-depth
look at the method you used that resulted in success? This has boggled my mind for the past few months, and I want to get to the bottom of it.
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underground
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I made a research here on this forum and i found somebody that had a very good yields of ~45-50g of ETN for every 35g of Erythritol
200 ml sulfuric acid
110g Ammonium Nitrate
35g Erythritol
So you can give it a try...
[Edited on 24-10-2013 by underground]
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Pyrotrons
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Hm, Ammonium Bisulfate. I trust that that is what it was. Thank you Rosco & Chill. It solidifies in my nitration bath during the addition of
the Ammonium Nitrate. When I add it, the ROCK hard, white solid forms that is difficult to remove. I have broken more than one beaker trying to bust
it off of the walls with screwdrivers. I really don't understand it, but I'm trying to fix that. I have added grotesque quantities of H2SO4 to try
and get it back into solution...as I assumed...probably incorrectly...that it was important! Chill, as far as my correlation between white
mass=Success and the lack thereof=Unsuccessful...it's possible that one or all of my reactions could have still worked had I not gotten frustrated and
dumped them. That would be would be disappointing.
Notes for my syntheses:
* I always use continuous hand stirring with a glass stir rod
* My reactions seem to always fume proportionally with the addition of NH4NO3. Makes sense (HNO3) sure, but I mention this note because at least one
other member of this site detailed a (successful) synthesis that for some reason did not fume.
Rosco and Chill, posts like yours make me want to seriously consider taking formal chemistry classes.
[Edited on 24-10-2013 by Pyrotrons]
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Rosco Bodine
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Stirring with a glass rod is not the safest manipulation for a sensitive nitroester, so you may want to rethink that one. In the alternative you can
keep on rolling the dice.
https://www.youtube.com/watch?v=J1EWf6O77jE
<iframe sandbox width="640" height="480" src="//www.youtube.com/embed/J1EWf6O77jE?rel=0" frameborder="0" allowfullscreen></iframe>
http://www.youtube.com/watch?v=l55NbooeUVY
<iframe sandbox width="640" height="360" src="//www.youtube.com/embed/l55NbooeUVY?rel=0" frameborder="0" allowfullscreen></iframe>
[Edited on 24-10-2013 by Rosco Bodine]
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