Sciencemadness Discussion Board

Trinitrotoluene preparation

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Zinc - 14-2-2008 at 12:29

2 days ago I used a procedure to make a mix of DNT/TNT posted on an another forum. It uses ammonium nitrate (I used sodium nitrate, 87 g) and H2SO4 (I used boiled down acid from a old car battery, 125 ml). And I used 20 ml of toluene. I got a red liquid that during washing solidified to a yellow solid that is a little waxy with some needles in it and a very weak smell.

The "perfect" method?

Fulmen - 15-2-2008 at 05:32

I'm looking for the "perfect" method for making TNT. One which doesn't require oleum and where the acid is reused for each precursor without any regenerating. Or would it be more expensive than using fresh acids for each step? From what I can gather you really don't need more than 65% HNO3 before the last step, and even then you can use it with a reduced yield. True?

I'd like to do a full synth including acid recovery, so it would be beneficial to keep the volumes down to a minimum. Not quite sure if the acid could be distilled without a dilution, I expect it could still contain some dissolved M/D/TNT that could mess up the process. If the spent acid is strong enough one could possibly distill 95%HNO3 straight off the spent acid. The alternative would be to dilute, still of 65% and then do an extractive run to get the good stuff.

Any thoughts on this?

PS: Fashist, AFAIK there is no such thing as dry/anhydrous magnesium nitrate. It is fully hydrated as the hexahydrate, and while it can be dehydrated to a certain degree it has never been isolated in a completely dry state. I believe the mono or dihydrate is as far as you can go.
Interesting to hear that you've succeeded in this process, my attempt failed completely. Any details you'd care to share with us?

[Edited on 15-2-08 by Fulmen]

quicksilver - 15-2-2008 at 05:48

I really can't comment of the concept of "perfect" but the re-use of acid has been discussed and implemented over time and referred to as a one pot synth on a lab scale. I think you can find a few examples in common literature. I know that Ledgard had one or two examples in his Preparatory Manual of Explosives; however the citations he lists are famous for being wrong. I looked up some of the patents listed for certain primaries and they just plain didn't exist.... but the "one pot" synths are listed there, plain as day. I know you can get some of them to give you mixed nitrated materials with no problem.

Fulmen - 15-2-2008 at 07:41

Thanks, I'll do a search and see what turns up.

Not too much on the net about this, but after calculating a bit it seems to be simple. Each reaction step produces water (one mol per mol toluene), but not enough to exclude it from further use. Nitric acid is also lost, but this can be added back.
According to this method:
one can use the acid from step 3 and simply add 70% HNO3, and the acid from step 2 can be used for twice the amount of MNT.

This seems quite promising indeed. Still need a distill for the 100% HNO3 and acid regeneration though.

[Edited on 15-2-08 by Fulmen]

Fulmen - 15-2-2008 at 15:40

OK, lets run through the math.

The synthesis calls for the following steps:
1: 10g Tol + 15 ml 50% HNO3 + 30 ml 50% H2SO4
2: 14,7g MNT + 11 ml 70% HNO3 + 20 ml 98% H2SO4
3: 19g DNT + 7,5 ml 98% HNO3 + 22 ml 98% H2SO4

The acid for step 3 contains:
39,7g H2SO4
11g HNO3
1g H2O.

The nitration will consume 1 mol of HNO3 and produce 1mol of water per mol DNT, so the spent acid will contain:
39,7g H2SO4
4,4g HNO3
2,9g H20.

Step 2 calls for:
36g H2SO4
11,2g HNO3
4,8g H20

A bit more sulfuric acid shouldn't change anything as long as the total acid concentration is the same, so by adding 6,6g 65% HNO3 and 2,5g 100% HNO3 the final composition would be:
39,7g H2SO4
11,2g HNO3
5,2g H20.

After the second step the acid will contain:
39,7g H2SO4
4,4g HNO3
7.2g H20

Step 1 calls for:
21g H2SO4
9,75g HNO3
30,8g H2O

So the acid from step 2 is actually more concentrated than required, so adding 65% HNO3 (8,5g) and enough water to prevent oxydation and we're done.

Total consumption should be 39.7g H2SO4 and 23.3g HNO3 for a 23g batch of TNT.

S.C. Wack - 15-2-2008 at 16:27

Originally posted by Fulmen
I'm looking for the "perfect" method for making TNT.

Then you're probably best off reading COPAE, Sanford, Fedoroff, Urbanski, etc. and doing your own experimentation. Let us know when you've found it.

[Edited on 15-2-2008 by S.C. Wack]

Fulmen - 15-2-2008 at 17:22

Perfect is a matter of definition, the perfect industrial process and the perfect amateur method are two very different things. All the "good" cources like Davis and Urbanski seems to list methods using oleum or large quantities of 100% nitric acid.
The method from Philou seems better for small quantities and limited supplies and as far as I can tell this is a verified method. It still require 100% NA but there might be possible to adapt it to a nitrate-method. Another way would be to make it from calcium nitrate and sulfuric acid. It doesn't work for pure NA as you just can't separate it from the precipitated calcium sulphate in any resunable yields, but washing it out with more SA could work.

S.C. Wack - 15-2-2008 at 17:31

Perfect is a matter of experimentation, and the perfect amateur method in this case I suspect to be pretty close to that in the references that I mentioned. Until you have product in hand from internet methods, crapbooks, or patents, you've only got talk.

Fulmen - 15-2-2008 at 18:00

I won't argue with that, talk is cheap. Unfortunately chems and glassware are not. Hopefully a few (!) hours of reading will save me from a few wasted experiments. I haven't sifted through all the industrial processes in Urbanski yet, perhaps they don't look so bad after I calculate the yields a bit better.
But I suspect these are optimized not only for yield and purity but also for time and volume since production capacity is largely a factor of batch sizes and reaction time.

zeppelin69 - 17-2-2008 at 19:23

I thought I would attach this link for reference. I am Masonjar Chemist on this forum (as well as RS in anyone cares). I created my own procedure for a one step TNT synthesis and it worked. Pictures were also included, I hope this isn't considered advertising, I'm not looking to break any rules here.

Fulmen - 17-2-2008 at 23:42

Nice work, Zeppelin. Seems like you've got almost a full yield from your toluene, but it does use a lot of SA (100ml) and AN (82g). A 3-step synth should be a lot more efficient (for multiple batches that is) and probably easier to perform as well. With a single stage you risk oxidizing the toluene in the beginning and at the end there may be too much water to get full conversion to TNT.

I haven't desided on the choice of chems yet, but I am looking more and more to AN/SA. Sulphuric acid is more available than NA, and unless one is to recover the acid it really doesn't matter too much. I would like to do a full synth including recovery, but the glassware i need for that isn't cheap.

[Edited on 18-2-08 by Fulmen]

Bonome - 19-2-2008 at 13:58

3 pics here, MNT, DNT and finally TNT

My MNT is contamined with DNT that's why it is orange.

[Edited on 20-2-2008 by Bonome]


chemoleo - 19-2-2008 at 15:05

Very nice Bonome. Could you give an account of your synthesis?

Bonome - 19-2-2008 at 17:46

Hi chemoleo, Like you can see I used 3 step method.
Here is the details of each reaction.
Sulfuric acid is from Drain opener and has not been concentrated. The concentration is approximately 94%. I based my calcul with that. For each nitration I used different stochiometrical amount. MNT: 1.1, DNT: 1.2, TNT: 1.5
Some people said to use 1.1 for each nitration. This doesn't work for the last nitration if you have sulfuric acid <98%
My nitric acid was made with ammonium nitrate. I did not distillate the acid because the sulfate doesn't disturb the reaction. The nitrate and sulfuric acid was mixed and I waited reaction to complete before adding it to the aromatic.
Of course all the nitration was under stirring (Magnetical is my case). I hope you have all the information you wanted.

------------------------------------- Reagents --------------------------------------
Ammonium Nitrate: 0,076 kg
Sulfuric Acid: 0,141 L
Toluene: 0,080 kg
Water: 17 mL
Total Batch Size: ~ 0,286 L
---------------------------------- Temperature ------------------------------------
Starting: 25-30 °C
Finally: 50-55 °C
Final Reaction Time: 1.5 hours
---------------------------------------- Yeild -----------------------------------------
Theoretical yield (%): 97%
Theoretical yield (kg): 0,115 kg
Theoretical yield (L): 0,1 L

------------------------------------- Reagents --------------------------------------
Ammonium Nitrate: 0,081 kg
Sulfuric Acid: 0,149 L
M.N.T: 0,115 kg
Water: 5 mL
Total Batch Size: ~ 0,29 L
---------------------------------- Temperature ------------------------------------
Starting: 50-55 °C
Finally: 80-85 °C
Final Reaction Time: 2.0 hours
---------------------------------------- Yeild -----------------------------------------
Theoretical yield (%): 97%
Theoretical yield (kg): 0,148 kg
Theoretical yield (L): 0,112 L

------------------------------------- Reagents --------------------------------------
Ammonium Nitrate: 0,098 kg
Sulfuric Acid: 0,181 L
D.N.T: 0,148 kg
Water: 0 mL
Total Batch Size: ~ 0,338 L
---------------------------------- Temperature ------------------------------------
Starting: 80-85 °C
Finally: 115-120 °C
Final Reaction Time: 2.5 hours
---------------------------------------- Yeild -----------------------------------------
Theoretical yield (%): 95%
Theoretical yield (kg): 0,179 kg
Theoretical yield (L): 0,108 L

The quantity was generated by a program I made to calcul all according to my 94% sulfuric acid, here is a screen shot. I create this program for big quantity so the value are rounded alot for little batch.

[Edited on 19-2-2008 by Bonome]


Bonome - 19-2-2008 at 17:57

I forget to said that the toluene I used was pure

[Edited on 21-2-2008 by Bonome]


JohnWW - 19-2-2008 at 18:05

Gosh, did you really use 120 liters of toluene? That would make a HUGE amount of TNT!

Bonome - 19-2-2008 at 18:10

yes there is alot of toluene lolll but I will not have to buy more for alot of time ;) and no I don't make a reation with 120 Liters... I don't have the appropriate equipement to do that. I can make 12L batch max.

[Edited on 19-2-2008 by Bonome]

[Edited on 19-2-2008 by Bonome]

Fashist - 1-3-2008 at 01:01

I Found Interesting Patent
Nitric Acid+Trifluoromethanesulfonic acid+DNT--Heat-->High Purity Tnt

Nicodem - 1-3-2008 at 01:18

Triflic acid is not particularly cheap (~ 2 EUR/g for reagent grade). It is many, many times more expensive than TNT. Using it to make a nitrating mixture is not particularly reasonable.

Fashist - 1-3-2008 at 01:26

Its true.
Merck Trifluoromethanesulfonic acid is 56 eur per liter.

markgollum - 1-3-2008 at 15:31

To Bonome and others who believe they have made TNT:
How do you know that what you have is in fact TNT and not DNT or a mixture of the two?.
You should take the melting range before you tell people what you have.
The color of TNT is heavily dependent on its ph history, even things like a bicarbonate neutralization or a sulphite wash can drastically affect the color if not done correctly.
TNT melts at 80.1C and I would not tell anyone that a certain procedure made TNT until the unsymmetrical isomers have been removed and the product melts no lower than about 75C.
DNT impurities in TNT drastically reduce the melting point and cause the product to exude an oily DNT/TNT mix over time. The melting range is very important and is really the only way to determine the quality of your product.
I really don’t understand how people and even the literature can justify throwing around yields like 97% for non analytical or industrial processes. I have done a fair bit of chemical syntheses and I am not ashamed to say that I HAVE NEVER GOTTEN a final product with a yield in that range for a non-analytical experiment, real world chemistry generally gives you yields of 65-85% of theory once all the purification steps are done.
Oh and Bonome, I hope that you aren’t trying to nitrate all that toluene, that picture is bothering me what would you need THAT MUCH TNT FOR ???. (and even if you have a legitimate reason, do you think posting a picture like that along with the commentary you gave is wise??).

497 - 12-3-2008 at 23:23

I have seen mention in a patent of using a dichloromethane-nitric acid mixture to nitrate toluene and friends. It actually says it is reactive enough to nitrate toluene at *-55C*. No other details were given for that specific reaction, but the patent did also say that it was gentle enough to nitrate phenol or 9,10 dihydroanthracene with very little oxidation and thus very pure products.

Just an idea, but I think it might be effective, maybe even easier, to produce TNT by mixing toluene with the DCM-Nitric mixture, you might need some concentrated sulfuric to suck up the produced water. The DCM shouldn't take part in the reaction and since water and sulfuric acid are not soluble in it, it would basically be 100% nitric acting on the toluene. According to the patent you wouldn't need the high temperatures usually used. I would guess this would result in substantially more pure TNT.

I was just thinking it could possibly be a good one step method that would require minimum quantities of acids.

quicksilver - 13-3-2008 at 06:38

Originally posted by markgollum
Oh and Bonome, I hope that you aren’t trying to nitrate all that toluene, that picture is bothering me what would you need THAT MUCH TNT FOR ???. (and even if you have a legitimate reason, do you think posting a picture like that along with the commentary you gave is wise??).

It really might be more appropriate to use a PM for commentary or questions regarding usage, functionality, or etiquette.

Fashist - 15-3-2008 at 05:05

Originally posted by CD-ROM-LAUFWERK
my TNT did melt around 81°C, wich is pure
the crackling is coming from entraped water in the TNT, u should meld it in a boling water bath and remove the water floating on top of it
than slowly cool it down, let the DNT crystallise out and pour the still liquid TNT out
repeating this two or three times will purify ur TNT to a mp. >80°C (if u make it properly)

May you Explain More ?
Interesting Method.

hector2000 - 15-3-2008 at 22:26

In the final Step The Problem Is Water.The nitration will not Complete if Density of You Nitric acid Lower than 90%.For Solve This Problem You Have Two way:
1-Use Oleum(The Amoung Of Oleum is very Important.Each Mole of Dnt need One Mole nitric acid And Need just one Mole of So3 No More!)
2-Use More Conc.Nitric acid(Use 3 Mole Conc.Nitric Acid for Every Mole DNT)

Pilot Plan For Making Tnt

[Edited on 17-3-2008 by hector2000]

Bert - 18-3-2008 at 06:21

hector, that's a very interesting picture. Is there a schematic drawing and/or flow chart of that pilot plant as well?

hector2000 - 18-3-2008 at 11:46

This is real plan.and this plan use new method for making tnt(new part in washing step)

[Edited on 18-3-2008 by hector2000]

Bert - 18-3-2008 at 20:21

What is meant by ONT? It would appear to be the Toluene feed stock?

microcosmicus - 18-3-2008 at 23:32

I assume he is being cute and writing "oudeno-nitro-touluene (0NT)" in
analogy with "mono-nitro-toluene (MNT)", "di-nitro-toluene (DNT)", and
"tri-nitro-toluene (TNT)". "Ouden" is the Greek word for "nothing" ---
actually "zero" is "meden" in Greek, but since that starts with an m
we can change the word a little.

[Edited on 19-3-2008 by microcosmicus]

garage chemist - 18-3-2008 at 23:53

I'm sure he means ortho- nitrotoluene.
Since the "mononitrotoluene" from the "first step" in TNT synthesis contains a few percent m-NT, the resulting TNT contains 3,5-DNT and is too impure for lots of applications.
By using pure ortho-NT, which is an important chemical intermediate for other things (toluidine, dyes), as the precursor this problem is circumvented.

hector2000 - 19-3-2008 at 00:01

ONT=ortho nitrotoluene

the step of toluene Nitration

old sulphite washing step:

[Edited on 19-3-2008 by hector2000]

Bert - 19-3-2008 at 07:12

Thanks, I understand the reason for using ONT as the initial feed now- From the perspective of someone proceeding with over the counter chemicals, it would probably be easier to start with toluene and do a sulphite wash of the crude product?

[Edited on by Bert]

garage chemist - 19-3-2008 at 07:25

Ortho-NT can be obtained from mononitrated toluene by fractional distillation, it boils at 222°C while p-NT boils at 238°C.
The p-NT is preferrably first separated from the crude MNT by freezing out with ice and salt, the separation is not entirely complete however, hence the need for subsequent fractional distillation.

hector2000 - 19-3-2008 at 07:28

Yes Sulphite Waqshing is Necessary If you want to have Pure TNT.
Anyhow (with ont or pnt or mnt) in the final Product(tnt) you will have other impure like c(no2)4 and... then sulphite washing or crystalization is necessary.

Zinc - 22-5-2008 at 03:58

Today I tried to make MNT. To 170 ml of H2SO4 (boiled down battery acid from a old car batter, very contaminated y some needle crystals, probably lead sulfate) I added 85 g of NH4NO3. When the ammonium nitrate dissolved I added 90 ml of toluene to the mixture. The toluene turned to clear yellow and then I heated the mixture to start the reaction Then the reaction started and I overheated it a bit so I coled it down in a water bath. Then I stirred the mixture with a measuring cylinder for around 20-35 minutes. After that I let it to sit and cool for around 45 min to 1 hour. Then I diluted the mixture with around three times of its volume with water and decanted the top layer (it turned from red to non clear orange). Then I added the MNT to water. And the MNT floated on top. It is supposed to sink (it always sank). And I could smell toluene in it. So it looks like it isn't completely nitrated. Does anyone know what did I do wrong?

Zinc - 22-5-2008 at 15:12

I have tried to remove the leftover toluene (and a small amount of water) from the MNT by boiling it away on a low gas flame. At first it didn't do anything, then suddenly splashed a few times, then for a minute or two it boiled nicely and then suddenly again it splashed forcefully (a lot of it went out of the baker). Some landed in the burner flame so everything caught on fire. I removed the baker from the burner and closed it with a flask to extinguish the fire. But the remaining MNT is now contaminated with fine carbon dust:( At leas it now sinks in the water. But I think that there is still some toluene left in it. Does anyone know why it splashed like that?

not_important - 22-5-2008 at 22:40

You said it had some water left in it. Water boiler at a lower temperature than toluene or nitrotoluenes, and the water-toluene azeotrope is lower boiling yet. Those conditions make it easy to superheat the water, which can lead to explosive boiling. You didn't describe your workup of the reaction products, you may have also have had dissolved salts and/or acid in the water; with much acid+nitrate you could have started nitrating the mix again.

It's always a good idea to dry liquids with low mutual solubilities with water before attempting to boil said liquids.

It's a bad idea to heat, especially boil, flammable substances over an open flame. It's even a worse idea to do this with nitrated organics. It's especially bad to do so when there's still droplets (or more) of water in them.

Get yourself an electric hotplate, and/or get a simple distilling rig, and use a sandbath to heat the flask with the toluene/MNT in it. Rig thongs so toluene vapours don't drift onto the heater.

MagicJigPipe - 23-5-2008 at 02:05

I figured it would be common sense to heat any flammable liquid with a flame. It just seems very counterintuitive.

Think about it. If the vapors collect somewhere and then somehow come in contact with the flame (or superheating occurs while oxygen is present in the reaction flask) you could have a fuel-air explosion on your hands. And don't say that's impossible because it's not. It just seems to me that it would just make sense not to heat flammable liquids with flame.

Would you boil gasoline on a gas kitchen stove? Even if you thought the reaction vessel was closed?

Sorry Zinc but this time I have to say, "DURRRRR!!!!!".

Zinc - 23-5-2008 at 02:48

Ye I know it was a stupid idea to heat it with a gas burner. But I don't have a hot plate. I must get one.

not_important - 23-5-2008 at 05:34

Originally posted by Zinc
Ye I know it was a stupid idea to heat it with a gas burner. But I don't have a hot plate. I must get one.

"Yes, it was not wise to step off the top of the cliff, but there wasn't a bridge across the canyon so I went ahead"

"True, the ship was unfinished and had no bottom, but I was in a hurry to set sail"

Sometimes it s better to not start the voyage when something critical is missing.

Axt - 23-5-2008 at 13:44

<b>Preparation of explosive substances in the laboratory. II. Preparation of trinitrotoluene</b>. Tseng, Chao-Lun; Tuan, Kun. J. Chem. Eng. (China) (1937), 4 59-64. Journal language unavailable. CAN 31:31940 AN 1937:31940 CAPLUS


cf. C. A. 30, 2003.3. Convenient lab. procedures for the prepn. of TNT (I) are described. One mol. PhMe, 132 g. concd. HNO3 and 190 g. concd. H2SO4 give at 30° 134.5 g. MNT (II) of d2525 1.166. One-half mol. of II, 49 g. HNO3 (sp. gr. 1.52) and 98 g. concd. H2SO4 give 86 g. DNT (III), the reactants being mixed at 60-70° and later raised to 90-100°. 36.5 g. of III, 146 g. concd. H2SO4 and 36.5 g. HNO3 (sp. gr. 1.52) give 43.5 g. of I; during this prepn. II is first dissolved in H2SO4 with warming, then HNO3 is added at 60°, and the temp. is subsequently raised first to 95° and finally to 120-5°.

[Edited on 24-5-2008 by Axt]

Leander - 4-8-2008 at 14:50

Last week I tried to produce some TNT myself, which resulted in a really strange product.

The synthesis was done in two steps, using the method Sobrero mentioned earlier in this topic to go strait from toluene to DNT using H2SO4 and a nitrate salt @ 60oC. This method gave me a 92% yield based on toluene, of slightly yellowish dinitrotoluene.

To add the last nitrogroup, I decided to use H2SO4/NH4NO3 again. A 75/25 H2SO4/HNO3 nitration mixture by volume was made, forgetting the NH4HSO4. The water content of the AN was onknown. The DNT was added in a 1:2 molar ratio of DNT/HNO3. After 2 hours of nitration @ 95-100oC with occasional stirring the acid was quenched in ~600 ml of water. Instantly a yellowish oil sunk to the bottom. The oil was washed with strait water and dried for further examination. Probably the relatively high water content of the mixture was the cause of the byproducts forming.

The crude oil seems to have a melting point of 5-8oC, and a density of 1.35 g/cc. After a day or two I noticed the colour of the liquid became slightly more orange, so I decided to wash the product with 5% ammonia solution. Upon contact with the oil the ammonia graduately turned bloodred. After washing with water again, the now yellow oil suddenly became a lot thicker, to an almost solid state. The stuff deflagerates from flame really lazy, taking over 10 seconds to fully decompose for a ~.5 ml drop, smelling really.. uuhhm.. 'nitro'! :D

Does anybody has any idea what the heck this product is? Since the nitration was done on a relatively moderate temperature with graduate temperature changes, I assume the benzene molecule is still intact. I assume most of the mixture consist of tetranitromethane, since it has a melting point of ~13oC, and is also a liquid at room temperature. Also, it's is a well known impurity in any TNT synthesis.

[Edited on 4-8-2008 by Leander]

Ritter - 5-8-2008 at 05:47

Patent has this to say about TNT manufacture:

Current methods of synthesizing TNT involve successive mixed-acid nitrations of the petrochemical toluene
(Milligan, B., "Isomer Distribution in Mixed-Acid Nitration
of Toluene. Evidence for Mass-Transfer Efects on Selec
tivity" Ind Eng Chem Fundam, 25(4), 783-789(1986). During this process, some undesired nitration isomers occur (a-, beta-, and y-trinitrotoluene) as well as incomplete nitration products (2,4- and 2,6-dinitrotoluene). These unwanted isomers are removed by sellite (sodium sulfte) washings.

Isomers with nitro groups ortho to one another react with the sulfite generating ionic, water-soluble products. These
washes have a characteristic red color, hence the name `red
water'. These washings are highly toxic and very expensive to destroy (incinerate). Because of this `red water' problem, there are no North American plants that will produce TNT.

Currently, all U.S. needs for TNT are supplied from overseas
sources where environmental standards are mild or non

This patent offers an alternative (but elaborate & expensive) synthetic alternative to classic toluene nitration:

[Edited on 5-8-2008 by Ritter]

TNT-1.jpg - 19kB

hector2000 - 6-10-2008 at 12:20

My answer to this topic:
Making Tnt isnt Difficult!!

Mononitrotoluene: use 2 mol nitric acid(65%) for every mole Toluen(better you extract ont) and 4 mole sulfuric acid(96%-98%)

Dinitrotoluene:use 2 mole nitric acid(96%-98%) for every mole Mononitrotoluene(ont is better) and 4 mole sulfuric acid(96%-98%)

Trinitrotoluene:use 2 mole nitric acid(96%-98%) for every mole Dinitrotoluene and 1 mole Sulfurtrioxide(dissolve in sulfuric acid)(oleum 20%)

about convert dnt to tnt:
Heat solution 3 hour at 110-115

Picture of final step(dnt to tnt):
Left beaker: oleum(20%)+nitric acid 96%
Right beaker: Dnt+sulfuric acid

Final Product melting point(without sulphite washing):75c

[Edited on 6-10-2008 by hector2000]

Cyrex - 9-10-2008 at 05:00

thanks @hector
i made trinitro according your recipe and my product melting point is 75 but when i add sodium sulphite(5 time it weigh 5%) my product color will be red and after washing it color wont change
my product is 500gram and after washing with 100lit water it decrease to 300gram and its color change to light brown
really i made tnt?
how can i pure it?

hector2000 - 11-10-2008 at 07:41

Mr Cyrex Please Explain Your Washing Step
Yes.really you made tnt.
if you use ont(ortho nitro toluene)then you wont have red tnt and there is no need for sulphite washing.

Pure Tnt Pic:

jmneissa - 31-5-2009 at 14:47

hey so sorry to reopen this old thread but this is by far away the best thread on TNT on these forums. Now my question is that there is a lot of process out there for making TNT. I have come to the conclusion that the 3 stage process is the best one. Now after reading books on TNT synthesis I have read about the so named "German Process" that is in the first stage the Toluene is reacted with nitric acid alone to reduce the formation of DNT and TNT. From this the ONT is extracted for use in TNT manufacturing. After this it is a simple two stage process. Reacting the ONT to DNT and the DNT to TNT. The question I have are the ratios of acids to other acids and the total ratio of acids to toluene per each nitration. Also I have a question about hector2000 picture. If he is using ONT as a starting material why does he have three nitrators? He only needs two. I see that some people have been more successful with different methods. I have no clue which method is better I have seen different concentrations of acids different temperatures, heating, cooling, NO2 fumes, no NO2 fumes etc..... There is such a broad scale of what will work. I was hoping someone would be able to point me int eh right direction a certain synthesis which is know to produce a high yield.

For Example in one synthesis I have read it says to just add all the toluene straight to the acids without regard for temperature. On the other hand another synthesis says carefully monitor temperature and not allow to go above a certain point and add acids to toluene not the other way around. Which way is right?? I don't know... This is continued throughout the broad range of synthesis I have read some separate spent acids others keep them... If anyone can clear up this I would greatly appreciate it! Thanks a bunch

quicksilver - 1-6-2009 at 05:40

There are several effective methods of nitration depending upon the needs of the surround. In plant level nitration, the needs of both refinement of the final product & the re-cycling of the acid have great impact. In a lab demonstrating levels of nitration as an education instrument; the needs are different. There really is no "best method". I have even seen crystal growth procedures, yielding 2.5 cm needles & the method of nitration(s) were designed for that agenda! TNT used to made in hundreds of Organic Chem classes exactly for that reason. It's damn easy to do, the issue of toxicity aside.

Frankly I would always monitor the temp level or the efficiency of your lab is compromised by oxidation; amongst other issues. Somewhere is the posting of the needles but the pic is not as sharp as could be. The sodium sulfite wash is a good idea as it is said to prevent the formation of "oils" in the final product. Depending upon the ability to monitor temp a promising mp is close to 80C; lower than that and there would exist a larger % of DNT in the final product. In terms of dangers there exists some if the temperature climbs as the manipulation of a flammable vapor exists initially on the surface of the reaction vessel.

[Just an opinion but] simply from the standpoint of one's notes, if the temperature is not recorded, the reaction from one level to another becomes sloppy & more akin to a "lucky-recipe" than anything else.

[Edited on 1-6-2009 by quicksilver]

darel - 31-7-2009 at 14:47

I have Jared Ledgards Third Edition of the Preperatory Manual of Explosives. In it, he gives two one step nitration synthesis.

The First:

TNT can be made by treating toluene with 99% nitric acid in the presence of premium unleaded Gasoline. The TNT is recovered by recrystaliztion and purified with 70% sulfuric acid.

The Second:

TNT can be readily prepared in a one step process using Boron trifluoride as a catalyst. 95-99% nitric acid is refluxed with toluene and BF3 at 90c for about three hours put into a seperatory funnel and the top half is TNT. The bottom fraction containing the BF3 is recycled. The TNT is purified by refluxing with 98% sulfuric acid for one hour.

Has anyone ever played with this. I found Boron for $68 a lb. Mix with HF to get BF3.

I will try this as soon as I get The BF3.

Page 276 for the BF3 catalyzed and bottom of 271 is the beggining of the Gasoline route.

[Edited on 8-1-2009 by darel]

entropy51 - 31-7-2009 at 14:56

darel, I don't know enough about TNT to comment on these specific preps, but be very careful of anything in any of Jared Ledgard's little books.

Some of what he writes is demonstrably horse hockey, some of it dangerous.

dann2 - 31-7-2009 at 16:29

Jared Jedgard's an asshole (excuse my french as we say around here). All and everything he writes should be ignored. Nitrate the book.

chloric1 - 31-7-2009 at 17:25


Wow, it sounds like your disregard for Jared is personal. I thought his stuff was rather suspect and I sent him an email asking if he tried to make anything he wrote about. He briskly said he did and they worked without and further explanation or evidence. One thing that really begs skeptism his lack of references. IRC most of his proceedures are from patents and he does not even state which ones they are. I believe he is just a lack luster chem grad who knew enough to B.S. the sheeple into buying his books.

[Edited on 8/1/2009 by chloric1]

dann2 - 1-8-2009 at 02:07

Never actually purchased the book so it's not THAT personal :P First came accross it on Google when I was looking for something about Chorates etc (my hobby horse).
My favourite is his little ditty regarding Ammonium Chlorate (extremly sensitive, unstable, unusable stuff).
This guy wants to see people loose their bits, or worse. Where on earth did he get the information below? It must surly be making it up off the top of his head after getting well 'jared up' (stoned) ,when he writes his wise words of wisdom. He has a number of books in print.
Going off topic a bit.......

jl.JPG - 65kB

[Edited on 1-8-2009 by dann2]

chloric1 - 1-8-2009 at 06:20

Man alive! Total misrepresentation! You consult the literature of even the turn of the last century you hear many accounts of ammonium chlorate spontaneously exploding. If no explosion then the salt is decomposed in a matter of weeks. Not hardly stable. Secondly, ALL chlorates are at least moderately toxic, definately more so than perchlorates. If I where to use this salt it would only be in solution and it will only be to prepare Ba or Sr chlorate free from K or Na.

But the most shocking was the statement about mixing with chromates, dichromates etc. What a nut job!

[Edited on 8/1/2009 by chloric1]

further afield, yet.

argyrium - 1-8-2009 at 10:53

in addition to the incredibly dangerous compatibility allegations, the remarkably novel approach used by Mr. Jedgard to produce NH4ClO3 from NH4OH/NH3 + CO2 should further dispel any credulity in his writing. Pretty frightening.

Formatik - 1-8-2009 at 11:02

Quote: Originally posted by dann2  
Never actually purchased the book so it's not THAT personal :P First came accross it on Google when I was looking for something about Chorates etc (my hobby horse).
My favourite is his little ditty regarding Ammonium Chlorate (extremly sensitive, unstable, unusable stuff).
This guy wants to see people loose their bits, or worse. Where on earth did he get the information below? It must surly be making it up off the top of his head after getting well 'jared up' (stoned) ,when he writes his wise words of wisdom. He has a number of books in print.
Going off topic a bit.......

"It is relatively stable".

This is more material for worst books thread. I've also noticed he used a copy and paste ChemSketch values for density of energetics even where the density is known and easily looked up in something like Federoff or even Meyer and Koehler.

[Edited on 1-8-2009 by Formatik]

Zinc - 22-2-2010 at 08:17

Sorry to bring up an old thread, but I didnt want to start a new one as this question is more or less suited for this theme.

I am now making some DNT from MNT, H2SO4 and NH4NO3.
When the reaction is finished I will dilute the mix with water and filter out the DNT. So could I neutralize the DNT with simple water and NaHCO3 washes or is it done some other way?

Well my attempt at making DNT failed.

170 ml of conc. H2SO4 (lab grade), 90 g of NH4NO3 (contaminated with approx. 4-5% magnesium nitrate) and 114 g of MNT were mixed and heated in a steam bath for 2 h. Then after it cooled I crashed the mix in cold water. A lot of liquid immediatley settled on the bottom of the beaker, and most of the water layer turned white, as some fine powder was dispersed in it. The upper cm or so of the water layer is transparent. I will let it stand over night. Perhaps the liquid soldifies as I heared that DNT if impure can take some time to soldify :)

[Edited on 22-2-2010 by Zinc]

quicksilver - 22-2-2010 at 13:49

Contaminating your synthesis with foreign materials makes deduction of what went wrong pretty tough.

Always mix to a clear solution your solid nitrates, making sure that the process is a slow one and that the materials are KEPT COOL (refrigerate all acids maintaining at least 10C) until use in synthesis demands a higher temp. Crude DNT solidifies in needle crystalline shapes very similar to TNT However when washed DNT will retain a yellow where the majority of TNT looks similar to light brown sugar. Continually check your temps. TNT or DNT % are sensitive to temp variations.
DNT will often have a percentage of TNT and visa versa thus you will often have what is commonly called "TNT oil". This washes off with dilute H2SO4 & sodium sulfite. Alkalies often sensitize nitrated toluene. The common "1 or 2-pot synthesis" will pretty much guarantee some DNT.

Read "Plant-Level" TNT production techniques. They often can clarify what in a minor scale, went wrong. Check Davis (pp 141-) and familiarize yourself with the "rule of Crum Brown". Most everything you need is in there.

[Edited on 22-2-2010 by quicksilver]

Zinc - 23-2-2010 at 07:05

Tahnk you for the advice.

Well the experiment worked acutaly. Today I checked it and the DNT soldified to a nice yellow mass. I will recristalise it to obtain a powder (the solid mass cant be washed as most of the DNt wont be exposed to the washing solution).

here's a visual comparison

quicksilver - 23-2-2010 at 12:32

Here you'll see needles of crude TNT and a comparison of DNT to TNT.
Depending upon temp control you can grow needles of TNT up to 3.5cm in length. note the "oil" in crude DNT. This exists in most any crude nitrated toluene. The addition of ammonium nitrate during WWII diminished this (and from getting aircraft maintenance personnel from getting sick.

comparison2.jpg - 64kBneedles2.jpg - 24kB

Zinc - 14-3-2010 at 02:31

Well I still havent recryctalised my DNT (didnt have enough time:()

I was thinking, could the DNT be recrystalised by disolving it in hot acetone, and then crashing it in a NaHCO3 solution to neutralize the remaining acid (I know that wont make nice big crystals, but I dont want them, I want powder)?

crossbow39 - 11-4-2010 at 14:01

I know this question doesn´t fit here perfectly, but I didn´t want to open a new topic.
I successfully made around 90g of TNT and now I want to test some compositions containing TNT.
One is torpex (42% RDX, 40% TNT, 18% Al, cast), but I don´t know how much PETN/EGDN/Nc is necessary as booster.
Will 5g do the job (I want to use as little as possible, but as much as necessary for a proper detonation, because I will test only 30-50 grams, and don´t want a 100g booster for setting off a 30g charge...) ?
Another explosive I want to try ist cyclotol, same problem.

Thanks for reply, crossbow

[Edited on 11-4-2010 by crossbow39]

hissingnoise - 11-4-2010 at 14:24

You have these several compounds in your possession and know nothing of their sensitiveness?
Isn't that strange!

crossbow39 - 12-4-2010 at 05:22

Of course a 100g booster is an exaggeration, but you know what I mean.
RDX isn´t easy to detonate at high density, so is TNT, especially when cast.
So my question is, will 5g of a HE booster suffice for a small charge?
Thanks, crossbow

hissingnoise - 12-4-2010 at 07:22

[rquote]Of course a 100g booster is an exaggeration.

So's 5 grams!
TNT, pressed in a detonator capsule is reliably detonated by 0.35g Hg(ONC)2.
Torpex is more sensitive than TNT due to its RDX content and the plastic mixture PETN/EGDN/NC is more powerful and more brisant than C4.

[Edited on 12-4-2010 by hissingnoise]

Zinc - 28-12-2010 at 04:02

Sorry to bring up an old thread, but I didn't want to start a new one.

I tried to make nitrotoluene (130 g of AN, 175 ml conc. H2SO4 made by boiling old battery acid and 116 ml of toluene). After mixing the AN and H2SO4 I added the toluene but the reaction didn't want to start so I heated it to cca. 60-70 C. After something like 30 min on that temp I let it to cool down overnight and after that diluted it with 600 ml of water. The toluene is now almost clear-yellow, it floats on water and the smell of nitrotoluene is barely noticeable. It seems that toluene didn't nitrate completely, so could I attempt to nitrate that toluene again, or would it be better to start with fresh toluene?

[Edited on 28-12-2010 by Zinc]

quicksilver - 28-12-2010 at 07:13

This was (used to be) a common classroom exercise. Kitchen chemistry won't cut the mustard with TNT, TNA, TNB, TXT, etc. The best of mixed acids and excellent temp control makes it a wonderful demonstration in refining one's ability to control conditions. Boiling down H2SO4 is generally used to bring it up a few % and to knock out any contaminants; not to start cold. It could clean up sulfuric acid drain opener becasue that is often used in pickling (metals) and anodizing so that the garbage drops to the bottom of the flask.
Nitrating benzene ring materials are about as "safe"as nitration get. baring fumes and some real jocular stupidity one has to seriously screw up to loose the entire upper half of one's body; but it's happened. I have seen needles grown as long as two full inches but the temp control and time must be monitored with professional accuracy.
The group is also known for it's toxicity. The old bomb loaders on fixed wing aircraft used to ware leather gloves which absorbed what was known as "TNT-oil" and both liver and skin cancer was the result.

nitro-genes - 13-8-2011 at 10:18

Just experienced the stranges thing...

I've never made TNT before, so together with a friend of mine we gave the 3 step synthesis a try.

We started off producing mononitrotoluene, after washing and heating the isolated mononitrotoluene at 100 deg C for 15 minutes, lightly yellow coloured oil, density 1.14. So far so good.
Next step dinitrotoluene: mononitrotoluene was added to mixed acids 70% nitric and 97% sulfuric, after slight exotherm at the beginning was heated for 1.5 hours at 90 deg C. Dinitrotoluene was allowed to separate on top of the mixed acids, and pipetted off into 90 deg. hotwater + bicarb, washed and allowed to cool down. It settled at the bottom of the beaker as as solid, melting point approx. 65 deg, density 1.35.

Finally, 1 part 97% Nitric and 2 parts 97% H2SO4 were added at once, the mixture heated up to 50 degrees celcius. The dinitrotoluene was added and the whole mix was refluxed at 100 deg. C. for 2 hours with stirring.

Now the strange part: Whereas the dinitrotoluene was a solid, the resulting oil after the final nitration was a liquid, even at room temperature. I checked density of the resulting oil, and it was 1.46. It is a pale yellow viscous oil, but very milky. After heating to 150 deg. C, it burns with quite yellow luminous soothy flame.

EDIT: It is starting to crystallize now, probably strange eutectic of DNT/TNT. It is unlikely though MNT would still be present. How could I be sure?

EDIT2: Any ways for purification without sodium sulphite?

[Edited on 13-8-2011 by nitro-genes]

nitro-genes - 13-8-2011 at 16:32

12 (!) consecutive washings with boiling water later, melting point has gone up to 73-76 deg C, density 1.53. I lost about 12% of the crude TNT in the process, the yellow wash water turns bright red/brownish with ammonia. The cast end product still has a faint smell of NOx and has become roasted-almond-brown . Amazing how difficult it seems to wash all acid out of the TNT. :-)

[Edited on 14-8-2011 by nitro-genes]

quicksilver - 14-8-2011 at 07:25

Best to avoid a strong base with TNT as it sensitizes it. Sodium sulfite wash in fairly warm (50C+) water will bet it done. product will be a light beige crystalline. Davis for details.

nitro-genes - 14-8-2011 at 09:04

Yes, I only washed the crude TNT with boiling water, but tested the light yellow wash water with ammonia, it runs a deep brown/red immediately. :) I don't have any sodium sulfite, for washing. Is there some solvent from which TNT will crystallize more easily than DNT and.or other unwanted isomers?

[Edited on 14-8-2011 by nitro-genes]

quicksilver - 14-8-2011 at 12:31

Shot in the dark, it would be an industry oriented question during war-time or areas where production facilities are not highly funded. I am not sure on this as I have read so many patents on TNT that I really don't remember many but ethyl acetate or acetone might separate your crude nitrated material. Conflict-period patents for UK & USA patents would be an easy find.

I don't have my scans and digital material separated but if you hunt down (via patent searches) something like "TNT, acetone" or "TNT, polar - non-polar solvents" you might find just what you are looking for ( around 1939-1941). In large batch industry, the issue at one time was very common as various methods of production yielded very crude end product. The pictures (above show a near white needle that cleaned up similar to lightly colored "brown sugar" colored material where the lower nitrated heavy crystals had at least 30% DNT (via another acid and sulfite wash). The "steam" method was a very common one also as tri-nitrated material melts at 70C or something close where the lower nitrated materials always run higher.

Your hot water most likely put both into one one: that why your "brown color" was deep. Had you some method to control the heat (steam manipulation, etc) you may have been able to see a separation.

nitro-genes - 14-8-2011 at 13:23

Thanks quicksilver I have found some interesting patents, but how about ethanol? Supposedly DNT's are more soluble in ethanol than TNT at RT. I'll give it a try..:)

quicksilver - 15-8-2011 at 06:02

Above 50 C, it's quite possible, however I don't know for certain. I'm frankly putting out ideas as I haven't had a chance to really narrow it down either- but I know you won't have a serious problem doing so. What we are discussing is a common industrial issue. My guess is that cost containment, ease of use and common availability will win the day. Now that we're talking about it, I'll bet I find just the right one and if so; I'll post it up here.

neptunium - 16-12-2011 at 10:14

i thought it was a little daring to add 99% nitric acid to gasoline my self i agree....i wouldnt do it

al93535 - 12-7-2012 at 06:39

I'm looking for some information on melt casting TNT with PETN to make pentolite. What I would like are pointers on which available books I can find this information. Or if anyone here knows the correct safe procedure.

Thank you!

magneet - 12-7-2012 at 11:25

Here's something:

Ive made it a time ago, be sure of a good ignition.

al93535 - 12-7-2012 at 18:15

While that exact link wasnt what i was looking for, you reminded me about searching patents!!! Thank you! Doing lots of reading! I'll post what i find for others.

Ok, here is what I plan to do:

Prepared petn which will be sized to -60+100 mesh, will be added to distilled water in a ratio of 400:1500 petn:water at 36 degrees F. Then TNT will be dissolved in acetone Nd brought up to 90 degrees F, ratio 400:600.

While the petn is vigorously being stirred the TNT/acetone will be added slowly. Thus causing the TNT to coat the petn when it comes out of solution. Filter and dry.

Melt the clongolmorate Granules in a beaker in a hot water bath at 85-90 degrees C. Pour cast into suitable mould with a funnel providing extra for the 10% shrinkage during cooling.

How's that sound

[Edited on 13-7-2012 by al93535]

Hennig Brand - 19-7-2012 at 06:28

Last year I experimented with nitrating toluene. I used ammonium nitrate and draincleaner sulfuric acid. The sulfuric acid titrated as about 91% concentrated. I used a three stage method, using ammonium nitrate, given by Bonome earlier in this thread. I was pretty sure that the acid wasn't strong enough for the final stage, going from DNT to TNT, but I gave it a try anyway. Bonome indicated that he was using sulfuric acid of 94% concentration, and IIRC I didn't make adjustments in my experiment for the lower concentrated 91% acid used.

I have recently been experimenting with melting point determinations in order to determine the purity of Picric Acid samples. I thought I would give it a try with the sample of TNT saved from last year.

The thermal mass in the picture is an aluminum block weighing 304g. There is a 1cm deep recess in the top of the block for the thermocouple probe, as well as a 1cm deep recess for the sample to be tested. A glass slide could be placed over the sample recess, to obtain a small increase in melting point accuracy. A propane torch is used to focus a small flame into the notch at the base of the aluminum block. A small block of dry cedar was placed below the aluminum block, to insulate the block and prevent heat loss. It is reasonable easy to accurately control the temperature of the sample with this setup. The big thing seems to be having a suitably large thermal mass.

The melting point obtained was 64C. According to the table taken from "TNT Trinitrotoluenes And Mono And Dinitrotoluenes Their Manufacture And Properties" by G. Carlton Smith, this melting point corresponds to either ~13% TNT or ~ 76% TNT. Given the color of the sample I think that it is probably the later, 76% TNT. The text is available for download from the forum library. I have included a jpg of the table from the text and a couple of pictures of the melting point apparatus used.

The TNT is definitely far from pure. However it can be nitrated further or be used to make a very nice cheddite explosive.

BTW, regarding pentolite, apparently TNT samples with quite a lot of DNT in them can still make very respectable pentolite (I have references if I can find them). The other advantage is that a little DNT greatly reduces the melting point, facilitating pentolite manufacture.

TNT-DNT Melting Points Table.jpg - 133kB TNT Melting Point 1.JPG - 156kB TNT Melting Point 2.JPG - 159kB

[Edited on 19-7-2012 by Hennig Brand]

Hennig Brand - 20-7-2012 at 08:32

I did do a sulfite wash. I also remember that I had to rinse an awful lot in order to get all of the red out afterwards.

My brother was renovating a rental unit a few years ago and he came across this large bottle of chemical on the basement floor beside some paint cans, etc. He knew I was into experimenting so he gave it to me instead of throwing it out. IIRC, the previous tenant was into photography. I think there is still around 4 lbs or so of sodium sulfite left in the bottle.

Sodium Sulfite.JPG - 164kB

al93535 - 22-7-2012 at 14:39

Thank you hennig!! I needed that melting point table! I could not find the forum library, however I was able to find the book a great help! thanks!!

[Edited on 23-7-2012 by al93535]

[Edited on 23-7-2012 by al93535]

Hennig Brand - 24-7-2012 at 10:33

No problem. For the forum library use the following link.

Look at the address bar at the top of your screen. Deleting everything in the URL after the domain name, and hitting enter, will bring you to a page with links to the forum, the library and other resources.

[Edited on 24-7-2012 by Hennig Brand]

Trotsky - 21-10-2013 at 21:07

Sorry to revive an old thread, but better than starting a new one. I was wondering if someone could tell me the following:

1) what is the real risk of a runaway with TNT? Is it similar to NC or more like ETN (which I've had runaway reactions the two times I've (attempted) to make it. I know the second and third nitrations require heating too more than 100C. Is the risk only in the first nitration?

2) I've seen people talk about using nitrate salts in making TNT. Is that really effective? I would think it would need to be more pure, at least for the third nitration. With huge excess does it work? I've seen people suggest using 3x the stochiometric ratio to ensure complete nitration to go straight to DNT.

How does DNT compare to TNT as an explosive? I'm sure I made some during experiments nitrating gasoline and kerosene, but that was a globby waxy mess* and not useful for drawing conclusions from.

*(which made for a very energetic fuel when burned, but awesome rocket fuel when mixed with KNO3- it burned like an energetic in open air but there wasn't enough NO3 groups on whatever it was to really burn well in confinement it seems).

Ral123 - 23-10-2013 at 09:09

I tried to make MNT with 60% nitric. It required fast stirring. Anyway I ended up with a runaway, a fire and short circuit in the room. Btw a friend made and detonated successfully cast TNT with 5% Al with only some AP. He used AN/H2SO4. I mixed mine with 40% ETN end couldn't set if off with azide-ETN-ETN/EGDN :/

Hennig Brand - 30-6-2014 at 10:15

Just above in this thread: I was unsure if what I had made was 13% TNT or 76% TNT. After nitrating some of the same material further I can say that it was actually about 13% TNT. There were some very interesting colors during the nitration and washing stages. About 95% yellow nitric acid and 95% sulfuric acid was used for the final nitration.

About 14 grams of the 13% TNT - 87% DNT mixture was used for the nitration. About 10mL of ca. 95% yellow nitric acid and 18mL of ca. 95% sulfuric acid was used to form the mixed acid. The nitrotoluene mixture was dissolved in the sulfuric acid with warming followed by nitric acid addition at 50-60C and then the temperature was brought up, and held, between 100C and 115C for 2 hours.

DNT-TNT ca. 87-13.jpg - 478kB Nitration 1.jpg - 400kB Nitration 2.jpg - 411kB Nitration 3.jpg - 451kB

This light green colored syrup was what I got after letting the nitration mixture cool and then transferring the nitrated toluene into a beaker with water.

Post Nitration High Viscosity Nitrotoluenes in Water.jpg - 432kB

[Edited on 30-6-2014 by Hennig Brand]

Hennig Brand - 30-6-2014 at 10:30

The product did eventually solidify after it was washed with water, and cooled more, and changed in color to a white color with a tiny hint of yellow. The product was then melted and washed under hot water with magnetic stirring. After 20-30 minutes of washing in 90-100C water the product came out with a pinkish color. A hot (90-100C) sulfite wash was next performed using about a 5% sodium sulfite solution. A lot of rinsing was needed after the sulfite wash to remove the red impurities. The final product was a brown color and had a melting point which would indicate that it was about 85% TNT. According to several sources, including Wiki, lower grade (grade B) TNT is brown colored because of the presence of impurities and has a significantly lower melting point than more pure grade A TNT..

Wash in Water Low Temperature Start 20-30C.jpg - 382kB Wash In Water 90-100C.jpg - 374kB Wash in Water 90-100C (2).jpg - 353kB After Wash In Hot Water (Damp Product).jpg - 162kB After Final Sulfite Wash (Dry Product).jpg - 475kB

I somewhat arbitrarily chose the quantities of acids to use for the nitration. If I had used the quantities from the journal article posted by Axt earlier in this thread I may have had better results or at least a higher degree of nitration.

The toluene I was nitrating has been through a lot though; many hours exposed to nitration mixtures at elevated temperature, with substandard nitration mixtures in many cases, which would likely contribute to higher amounts of impurities being formed. The purity of the hardware store toluene is also an unknown.

[Edited on 30-6-2014 by Hennig Brand]

nitro-genes - 30-6-2014 at 11:35

Familiar photos, reminds of the 3 phase synthesis of TNT I did once, also noticed that the DNT produced during the 2nd nitration had a ssemingly higher melting point than the product obtained after further nitration to TNT using destilled 95% WFNA + 98% SA. Some eutectic is most likely formed with DNT or maybe the nitric acid itself. Didn't had sulfite at that time, took me 20 washings or so with demineralized water to raise the melting point to close that of TNT. The product I obtained back then was slightly yellowish not the brown colour in your last picture, any idea what the impurities are? Seen the nearly identical synthesis used it appears the sulfite treatment to remove isomers may actually be (partly) responsible for the brown colour?

[Edited on 30-6-2014 by nitro-genes]

Hennig Brand - 30-6-2014 at 18:02

The following was basically taken right from COPAE, though the words may have gotten changed around a bit.

From COPAE, sodium sulfite reacts with and allows easy removal of Beta-TNT (2,3,4-trinitrotoluene) and Gamma-TNT (2,4,5-trinitrotoluene) to form red colored materials which are readily soluble in water. The sulfite leaves the Alpha-TNT (2,4,6 -trinitrotoluene) and any TNB, TNX and 2,4-dinitrotoluene unaffected. Concentrated sulfuric acid apparently removes dinitrotoluene most readily of the solvents listed in COPAE as the ones most commonly used, which include alcohol, solvent naphtha (mixed xylenes), carbon tetrachloride, and concentrated sulfuric acid. The organic solvents remove Beta and Gamma TNT better, but all of these solvents also remove some of the Alpha TNT as well as the impurities. The material dissolved by the sulfuric acid can be recovered by dilution with water. The organic solvents are recovered by distillation, dark brown liquids are left as residue known as TNT oil and are used in the manufacture of non-freezing dynamite. According to COPAE the best process of purification is to agitate the crude TNT with a warm solution of sodium sulfite.

TNT seems like a lot of extra trouble for a material that is only an improvement over picric acid as a main charge if filling artillery shells or something similar was the objective. I think Pentolite boosters would be nice though and apparently very easy to make. Warm liquid TNT apparently dissolves PETN quite readily and TNT with a fair bit of DNT in it still makes decent Pentolite.

There is a lot I don't know about TNT. It seems like there are quite a few strange things that can form for various reasons when making TNT and that last nitro group can be a real pain to add unless you have the right strength and quantity of acids as well as having the temperature and reaction time dialed in properly. I don't think making TNT is all that complicated, but it is not really well suited to the hobbyist the way that picric acid is for a variety of reasons. It is much harder to effect the trinitration with TNT and with the materials (acid strength) normally available to the home chemist it is not nearly as economical to do so either. Picric acid can be done in a one pot synthesis, in high yield and purity and without the strongest acids. Many other useful materials can be made from picric acid. Picric acid is slightly more powerful than TNT as well. TNT is still interesting to learn about and one of the nicest aspects of experimenting with it is that there is so much good reading material available because it was such a widely used explosive.

[Edited on 1-7-2014 by Hennig Brand]

PHILOU Zrealone - 1-7-2014 at 11:13

Possible other contaminants: DNBA, TNBA, TNB!

DNT and TNT may also oxydise in boiling HNO3 with NxOy to dinitro and trinitrobenzoic acid...the later can decarboxylate to trinitrobenzene...

About the nitrated benzoic acid, a simple warm wash with concentrated NaHCO3 or Na2CO3 (or NaOH diluted) will make the soluble benzoate salt pass into water; Acidification will crash it out. Concentrated NaOH should be avoided since it is able to deprotonate TNT and form a red colorfull soluble nitronate salt what renders the TNT more sensitive!
CH3-C=C-NO2 + OH(-) --> CH2=C-C=N(O)-O(-) + H2O
(the aromatic ring was left aside)

Separation of TNT and TNB might be more tricky!

Hennig Brand - 1-7-2014 at 14:05

Thanks for the pointers. I gave the warm NaHCO3 solution wash a try and there was considerable bubbling, but the TNT is still brown. I have been reading about TNT recrystallization from nitric acid in "Military Explosives" and "Explosives" by Meyer. Meyer suggests using 62% HNO3 and according to both sources this recrystallization technique is very effective, but wasn't used much for other reasons for which there is some explanation in "Military Explosives". Of course the sodium sulfite wash is supposed to be very effective too, but not as much as recrystallization from HNO3. It looks like I oxidized the hell out of it during nitration. Oh well, it's all a learning process.

Hennig Brand - 18-7-2014 at 08:11

Quote: Originally posted by nitro-genes  
The product I obtained back then was slightly yellowish not the brown colour in your last picture, any idea what the impurities are? Seen the nearly identical synthesis used it appears the sulfite treatment to remove isomers may actually be (partly) responsible for the brown colour?

I would tend to agree with you, especially after reading the following patent.

Attachment: US1975598 Purification of TNT.pdf (420kB)
This file has been downloaded 525 times

greenlight - 7-11-2014 at 18:06

Does anyone at all trust Jared Ledgard's 3-step Trinitrotoluene synthesis in his book a Preparatory Manual of explosives in regards to danger of runaway or bad yields.
I tried it with 62% nitric acid because it is all i had at the time and scaled it down a lot. I used:

111.5ml 98% Sulphuric acid
92.5ml 62% Ntric acid
62.5ml toluene

And then for the dinitro step:

107.25ml 98% Sulphuric acid
70ml 62% Nitric acid plus mononitrotoluene from first step

And for the final trinitro step:

133.12ml 98% Sulphuric acid
30ml 62% Nitric acid plus dinitritoluene from last step

I obtained 75g of what i assume is pure TNT after crashing into ice-water, but is this a good yield?

NeonPulse - 7-11-2014 at 18:55

I think you need strong nitric for the last step. Testing the MP of your product will giv a good indication as to what you have. I myself am looking for a more challenging nitration and am looking at attempting the 3 step process and will be using sulfuric and nitrate salt for the mono and di nitrations and distilled nitric for the final step but before I do ski was wondering about the smell. People have reported that the smell is pretty strong and recommend doing this outside, which I will, but how bad does it smell? Is it really strong? If anyone who has performed these nitrations could help that would be greatly appreciated. NP.

greenlight - 7-11-2014 at 21:42

When i did the 3-step nitration the smell was quite strong especially on the last steps where the temperature was very high (100degrees+). I did it in a medium size shed and it definately did fill up the whole space inside with a sweet strong smell that i noticed when i removed my mask. It actually smells quite nice, its just an unusual smell
It wasn't too bad outside if you are worried about neighbours smelling it but it seemed to stick to everything inside for a while afterwards.
Neonpulse, will u be using red fuming nitric or vacuum distilled white nitric and what salt, potassium nitrate?

[Edited on 8-11-2014 by greenlight]

Hennig Brand - 8-11-2014 at 04:14

I found that the strongest smell in the reaction was from the mono-nitrotoluene product from the first step of the three step process (a lot of people describe it as an almond smell). I personally have a pretty serious unpleasant physical reaction to mono-nitrotoluene, however, many people seem to describe it as just a really strong unpleasant smell. Also, depending on the materials and process used the product of the second step can still smell strongly of mono-nitrotoluene. The temperature gradually increases all the way up to 110-120C or so by the end of the final stage of nitration which will of course result in greater acid vapor production (acid loss), since vapor pressure is directly proportional to temperature, which is very bad for one’s health (if inhaled) and weakens the nitration mixture. During the final stage of nitration maintaining the strength of the mixed acid is necessary to obtain TNT of high purity directly from nitration. The reaction flask should be fitted with a reflux condenser, especially during the final stage of nitration.

I haven't gotten around to it, but I do plan on synthesising some TNT in the next little while. I have made equipment that will allow me to easily make SO3 and I plan to use it to produce an anhydrous mixture of nitric and sulfuric acids for the final stage of the nitration. Like NeonPulse, I plan on using sulfuric acid and a nitrate salt for the first two stages of the nitration, or I may combine the first two stages somehow in order to help limit my exposure to the unpleasant mono-nitrotoluene (even if it means being more wasteful of materials). Below is a link to the posts I made about SO3 production around the time I was working on it earlier in the summer.

DNT Synthesis In One Step

Hennig Brand - 25-11-2014 at 08:17

I spent the last few days making some TNT and taking a lot of pictures along the way. The nitration was performed in two steps; toluene was nitrated to DNT in one step and then DNT was nitrated to TNT in a second step. I will first report on the DNT portion of the experiment, since I have a lot of pictures for each section. I had sixty or more pictures for the DNT step alone, which I pruned down to twenty five.

Some time was spent reading through COPAE and Urbanski and the nitration mixture used was based on numbers from an old Italian method described in Urbanski Volume 1, pg 363.

From toluene to DNT

Nitration Mixture:

In order to make a nitration mixture approximating these numbers, ammonium nitrate and 91% sulfuric acid was used. The reaction between the nitrate and sulfuric acid was assumed to be ideal and represented by the following chemical equation.

NH4NO3 + H2SO4 ---> HNO3 + NH4HSO4

A 10% excess of HNO3 was used (though I might increase it to 20% next time around)

For 1g of toluene:

1g / 92.14g/mol = 0.01085 mols toluene

T ---> DNT takes two moles of nitric acid (ideally), used 10% excess

2 * 0.01085 * 1.1 = 0.024 moles of HNO3

therefore need 0.024 moles NH4NO3 & 0.024 moles H2SO4 to form the HNO3

mass of NH4NO3 needed = 0.024 moles * (80.052 g/mol) = 1.92g
mass of H2SO4 needed = 0.024 moles * (98.079 g/mol) = 2.35g
mass of HNO3 produced 0.024 moles * (63.01 g/mol) = 1.51g

Using the percentages from Urbanski for the nitration mixture:

mass of H2SO4 needed for nitration mixture = 1.51g / 28 *60 = 3.24g
mass of H2O specified for nitration mixture = 1.51g / 28 * 12 = 0.65g


For 50g of toluene used:
96g NH4NO3 (recrystallized and oven dried fertilizer grade nitrate)
(117.5 + 162g) / 0.91 = 307.1 g, 91% H2SO4 (or ca. 169mL at 1.82 g/mL)

H2O added with H2SO4 (NH4NO3 was oven dried and assumed perfectly dry):
0.09 * 307.1 g = 27.64 g

The numbers (neglecting NH4HSO4):
75.5g HNO3
162g H2SO4
27.6 H2O
Total mass = 265.1g

Percent water = 27.6g / 265.1g * 100% = 10.4% (less than the 12% specified by the Italian numbers)

The NH4NO3 was dissolved in the sulfuric acid the night before the nitration was to be performed. The 50g of toluene was weighed out and added to a 1L Erlenmeyer flask which was equipped with an improvised air cooled reflux condenser. Addition of the nitration acid took about 3 hours and was done with a 25mL burette. The temperature started out at about 30C, but was raised all the way to 80C by the end of the 3 hours and then was held at 80C for an additional 2 hours once all the nitration acid had been added. It is clear from the pictures that as the nitration progressed the color of the mixture darkened to a maroon color and gradually lightened again to a light yellow color. Strong magnetic stirring was used throughout.

The mason jar in the first picture holds about 1/4 of the nitration acid made from NH4NO3 and 91% H2SO4. I forgot to take a picture of it at the start. The second picture shows the 50g of toluene in the flask just before the nitration was started.

Nitration Acid Mixture.jpg - 433kB 50g of Toluene.jpg - 411kB Apparatus.jpg - 477kB 1.jpg - 377kB 2.jpg - 366kB 3.jpg - 375kB 4.jpg - 373kB 5.jpg - 428kB 6.jpg - 353kB 7.jpg - 379kB

[Edited on 25-11-2014 by Hennig Brand]

[Edited on 7-12-2014 by Bert]

[Edited on 7-12-2014 by Bert]

Continuation of Nitration and Color Change

Hennig Brand - 25-11-2014 at 08:25

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[Edited on 25-11-2014 by Hennig Brand]

Post Reaction Work-up

Hennig Brand - 25-11-2014 at 08:50

After the three hour addition time, and two hour heating at 80C, the stirring was continued but the mixture was allowed to cool. The stirring was stopped once the temperature had dropped to about 60C and the DNT was allowed to rise to the surface and collect. Solidification did not happen until about 50C. Once the reaction mixture had cooled to 20-30C the DNT cake was broken up with a large, stainless steel, flat head screw driver and scooped out with a spoon. Diluting the spent acid mixture precipitated another small amount.

The collected, and water washed, DNT was put back in the flask with about 250mL of clean water and heated to above the melting point of the DNT. Vigorous stirring was applied for 15-20 minutes to help dissolve water soluble impurities. The flask was then allowed to cool to room temperature, at which point the water was drained off and the DNT cake was washed a couple of times with small quantities of cold water. The cake was then broken up with a bamboo skewer and dumped from the flask. The chunks of cake were then allowed to dry and then weighed.

Yield of Crude DNT

Theoretical Yield:
50g / (92.14g/mol) * 182.134g/mol = 98.84g

Actual Yield = 100.2g (not counting an estimated 1g not retrieved as fines from wash water)

Percent Yield : 100.2g / 98.84g * 100% = 101%

The product is not pure DNT, but contains some MNT and TNT, as well as at least a small amount of other impurities. A very small amount of water would also be included in the weight. Nevertheless, the yield is very good.

18.jpg - 298kB 19.jpg - 426kB 20.jpg - 324kB 21.jpg - 355kB 22.jpg - 295kB Yield.jpg - 251kB

[Edited on 25-11-2014 by Hennig Brand]

Rosco Bodine - 26-11-2014 at 00:43

There is a file attached to this linked post that may be useful

DNT and aluminum powder at about 5% and 1% IIRC make one of the best sensitizer systems ever found for NH4NO3

Hennig Brand - 26-11-2014 at 18:36

Thanks for posting the great article. I have been looking it over off and on for more than a week. :)
That ammonium nitrate sensitizer sounds really interesting. Do you have any reading material on it?

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