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Author: Subject: ETN synthesis problem
maxidastier
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[*] posted on 1-5-2010 at 04:36


it fu**ing didn't work with dissolving Erythritol in H2SO4 and then adding nitrate salt ammonium nitrate.
At 50°C it fumed so much, I think all nitric has fumed away. Seems right with dehydration of AN.
Yield is so fu**ed up.
Either I'll try now KNO3 or I will do that: Half amount of H2SO4 for dissloving Erythritol, another half for nitrate salt, but at low temperature. When nitric acid has formed, then I can try rise temperature again...
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quicksilver
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[*] posted on 1-5-2010 at 05:20


NO, when the commonality is weight; a conversion is based on density. NHO3 1.51 would be 1.5gr as expressed in one's formula. H2SO4 also depends on density level - 93% weighs less than 98% so the arithmetic starting point depends on your level of purity in liquids presented in grams: weights not volumetric milliliters.

The majority of properly expressed formula is done so in a commonality, even if the expression some use is "recipe'". Be very careful of simplistic "recipes" as they often are written by people who don't do the math first; then the lab.

[Edited on 1-5-2010 by quicksilver]
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maxidastier
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[*] posted on 1-5-2010 at 05:52


so I add 60 g of nitrate salt to 100 g of H2SO4 95%?
I tried, but it's impossible to stirr...
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gnitseretni
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[*] posted on 1-5-2010 at 15:05


Question..

After the last addition of the Erythritol, instead of letting the mixture sit to nitrate for an hour and stirring every once in a while.. could that nitration time be reduced to say HALF an hour if you stir the mixture continuously by mechanical means?

I was thinking of making a little stand and attaching a hand mixer to it. I'll make one anyway regardless of the answer, just would like to know if I need to turn it off after an hour.. or half an hour.

I actually made such a mixer before, but I took it apart a while back when I decided to quit the hobby. I sold my acids and everything!! Fuck!! People even warned me I would regret it.... I should've listened :P
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maxidastier
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[*] posted on 2-5-2010 at 01:58


nitration time is 20-30 mins, but it doesn't hurt if you make it 45 mins; stirring, at least every 5 mins, is important.

@quicksilver: Every "recipe" I tried, even from that thread here, says 100 ML to 60 g (50ml to 30g), not 100 g to 60 g!!
So all those recipes are wrong?

[Edited on 2-5-2010 by maxidastier]
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quicksilver
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[*] posted on 3-5-2010 at 05:34


One of the reasons NOT to use recipes is that it doesn't teach chemistry. The convention of using all the same units of measurements (especially weight) is so ingrained that I use it consistently -that one reason NOT to use recipes but do the math and determine if you have it right. 100ml appears correct if the density level is 1.81. But mixing weights and volumes is a poor idea unless it's noted. Recipes are not chemistry.
Standard convention aside, I made more than one mistake in notation.
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maxidastier
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[*] posted on 4-5-2010 at 07:17


I have 95% H2SO4...so do I need 100 g or 100 ml??
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hissingnoise
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[*] posted on 4-5-2010 at 07:48


You need to find a simple hobby. . .
Stamp-collecting, perhaps?


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not_important
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[*] posted on 4-5-2010 at 08:04


The reason liquids are measured by volume rather than by weight is that it is easy to pour liquids than weigh them, and more particularly once was once much more so. But to use volume you need to know the density of the liquid, so that you can calculate the mass that volume represents and from that the molecular proportions.

So, how grams of H2SO4 is there in 100 ml of 95% H2SO4? Should be easy to find a table of densities for various strengths of aqueous H2SO4.

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The WiZard is In
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[*] posted on 4-5-2010 at 09:15


Quote: Originally posted by quicksilver  
One of the reasons NOT to use recipes is that it doesn't teach chemistry. The convention of using all the same units of measurements (especially weight) is so ingrained that I use it consistently -that one reason NOT to use recipes but do the math and determine if you have it right. 100ml appears correct if the density level is 1.81. But mixing weights and volumes is a poor idea unless it's noted. Recipes are not chemistry.
Standard convention aside, I made more than one mistake in notation.



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they were Chemical Sets. Chemicals yes - chemistry limited.


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maxidastier
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[*] posted on 5-5-2010 at 03:12


@noise: maybe you just stop making noise
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hissingnoise
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[*] posted on 5-5-2010 at 04:34


If you want to play with high explosives you need to be able to think for yourself. . .

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maxidastier
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[*] posted on 5-5-2010 at 06:10


So I'll try to find out how many milliliters of 95% H2SO4 are the same as 100 g of 100% H2SO4, right? To these 100 g / X ml 95% H2SO4 I add 60g nitrate and 15 g Eryhtritol...
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[*] posted on 15-5-2010 at 02:18


when the task is 100g H2SO4/60gNitrate/15gErythritol, then 100ml of 95% H2SO4 are way enough, because:
100g H2SO4 are needed and 100 ml 95% H2SO4 contain 100*1,834g/cm³*0,95= 174,23 g H2SO4.
Please correct me.
I think it doesn't hurt if you use too much of H2SO4 than too little?
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[*] posted on 15-5-2010 at 10:30


Quote: Originally posted by maxidastier  
.
I think it doesn't hurt if you use too much of H2SO4 than too little?


A synthesis is not a recipe. A synthesis is generally a balanced equation of reproducible type. In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions. In modern laboratory usage, this tends to imply that the process is reproducible, reliable, and established to work in multiple laboratories.

A chemical synthesis begins by selection of compounds that are known as reagents or reactants. Various reaction types can be applied to these to synthesize the product, or an intermediate product.

In organic chemistry the maintenance of a variable such as "this much H2SO4 / that much H2SO4" will NOT yield a reproducible result! To use "too much" or "too little" is not chemistry & will NOT yield a synthesis. It may yield a reaction; that consistently has a variable - and this teaches only that. The "yield" in that instance is at best, an accident.

Therefore; it damn well is inappropriate to not measure your reactants. You are discussing the synthesis of a high explosive. Perhaps one of the most serious agendas in lab chemistry.
To not do all the background study necessary to determine your OWN answers is to invite disaster! I wrote recently about someone who lost an eye & thumb in a synthesis of NG. I do not know whether he knew the lab techniques or chemistry necessary to prevent that tragedy; however, he might have prevented it.
I dearly hope this is the LAST of this thread. PLEASE do yourself a favor and listen, study & do your own work. You risk an extremely serious situation & out of a sense of humanity and compassion I hope you take this advice to heart.

End this thread: study the elementary synthesis process. Study the proper Lab techniques. READ books on proper lab technique & remember them.
There are very FEW accidents, in reality there is negligence. Ignorance of proper technique is negligence & just as with firearms, it is too late to say you're sorry if bad becomes worse.

You may never really realize the compassion in this response; but it may really save your butt.




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maxidastier
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[*] posted on 16-5-2010 at 05:43


Would you be so kind and tell me: What is so dangerous about adding too much H2SO4 IN THIS PARTICULAR synthesis?
Anyway, chance of a runaway or anything is very low with ETN compared to others.
Sulfuric acid is stripping away hydroxyl groups from the erythritol and the protonated hydrogen from nitric acid and absorbing the water that is produced. Concentrated sulfuric acid is acting as the limiting reagent, once it has absorbed enough water it will no longer attack the polyol. This means less chance of destroying unnitrated or partially nitrated erythritol.
I need H2SO4 for two thing: the one mentioned above, and, of course, producing nitric acid.
My question again: What is the best amount of H2SO4 (in gramms, milliliters or whatever)?

And btw: Be sure: I'm watching my ass...
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[*] posted on 16-5-2010 at 06:40


I found that using 100mL 98% H2SO4 per 7.5g erythritol gave me back a yeild consistantly 1.8 times the amount of erythritol used. I used KNO3 fyi
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[*] posted on 17-5-2010 at 10:19


And how much KNO3?
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[*] posted on 17-5-2010 at 17:51


Maxidastier, let me remind you of your own words earlier: "We need to try out different ways if making ETN"

It seems that you have tried many things, but I don't see the sort of systematic investigation that you need to establish patterns and investigate hypotheses. Work in small batches to conserve reagents before scaling up, vary one experimental parameter at a time, and try to repeat the conditions of a particular synthesis a few days apart so you can see how much uncontrolled variance in yield you can expect even when you're trying to do the same thing again.

Although not strictly needed to investigate changing reaction conditions, you'd also make faster progress in interpreting prior writings if you read up on stoichiometry. Nobody is born knowing it; there's no shame in needing further education. But you will ask more effective questions and learn better if you acquire this information before continuing the quest for optimized ETN synthesis.




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Justin
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[*] posted on 18-5-2010 at 10:51


^^ i agree very much, after my first few small scale ETN synths with good yeilds i jumped up to 60g erythritol, this amount however produced horrible yeilds, 50g ETN!. So basically i wasted good reagents!!! Very good advice Polverone
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maxidastier
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[*] posted on 19-5-2010 at 07:10


That's not the point. I always made it small scale. My question is only how much of every ingredient is needed.
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[*] posted on 19-5-2010 at 08:29


Start by writing a balanced equation for the electrophile nitronium, since this is what nitrates the sugar.

Though even with correct amounts, you shouldn't obtain a yield as good as using nitric acid since potassium nitrate and sulfuric acid form a less active nitrating system.

In the real literature, I've only seen this nitration system being used for aromatics. The only good point about it is the water of nitric acid is avoided and also less toxic fumes than from something like handling fuming nitric acid.
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[*] posted on 19-5-2010 at 10:48


I did this synthesis a few years ago and it seemed that the
yield problems come from problems with mixing. As more E is added the mixture becomes thicker. The ETN seem to form
clumps and I think the ETN may coat the outside of the E
granules and prevent the acid from reaching them. The
result is a lot of partially nitrated product which is water
soluable.

It seemed to help to make sure the E was very finely ground.

Other things that helped were to boil the acid to remove as
much water as possible. If the acid is 93% by weight (what
people claim for Rooto) it is only 71% acid on a molecular
basis (3 molecules of water for each 7 molecules of H2SO4)
so boiling it down to 98% is important. I assumed one
molecule of H2SO4 is needed for each molecule of HNO3
produced and for each molecule of H2O produced or present
at the start. If NaNO3 or NH4NO3 are used as the nitrate
salt they may also contain water. I tested my NH4NO3
by heating it to melting in a test tube and did not observe
any condensation at the top so it seemed to be dry.
My NH4NO3 also dissolved cleanly in water so it seemed
to be free of clay

My results:

On a Mole ratio basis: 1 C4O4H10 : 6 NH4NO3 : 11 H2SO4

20g H2SO4 (Rooto)
Boiled off 2.6 grams of it
Added 8g NH4NO3
Added 2g C4O4H10 (slowly at 0C)
Then let it stand for 1hr,
drowned in 100ml of ice water.
Needed to filter, the crystals would not settle out.
Got 2.6g product = 52% still not great.
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[*] posted on 24-5-2010 at 07:46


what are the effects of excess water in the reaction mixture? why would the yield be less using 30% concentration sulphuric acid and 3 times the nitration time.
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[*] posted on 24-5-2010 at 08:24


Water interferes with the nitration reaction (A-C hydrolysis) and 98% sulphuric acid in nitration mixtures binds up H2O to minimise this hydrolysis of the formed product.
No yield of nitrated product is possible using 30% H2SO4 for any length of time.
The water it contains *must* be boiled off before it can be used for nitration. . .

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