NG synthesis failures, need diagnoses

[Al Sheik Yerbuti]

Nitroglycerin, glycerol trinitrate, NG etc. Why am I getting nothing!? Here's what I do, with lots of pictures (all pics can be enlarged by clicking):

http://img409.imageshack.us/img409/6388/ngtwo03dg8.th.jpg (http://img409.imageshack.us/my.php?image=ngtwo03dg8.jpg) http://img411.imageshack.us/img411/9625/ngtwo06uj4.th.jpg (http://img411.imageshack.us/my.php?image=ngtwo06uj4.jpg) http://img267.imageshack.us/img267/4229/ngtwo10lc7.th.jpg (http://img267.imageshack.us/my.php?image=ngtwo10lc7.jpg)

Pic 1: I start with nitric acid (in flask) and sulphuric acid (in beaker). both as strong as possible, ratio 2:3 .
Pic 2: I cool acid mix in cold water, I attempt to keep temperature at 22C or less. I will add glycerin slowly and keep cool. Ratio of glycerin to acid mix is 1:4 . I let temperature fall to 15C while swirling in water, and add no more until temperature comes back up to 22C. Swirling all the time. I cool again, add more glycerin and repeat cooling, swirling and adding until glycerin is all added. I never let it get above 25C, always try for below 22C. When all is added, I usually have a yellow solution, clear, looks a lot like canola oil.
Pic 3: Then problems begin. I keep it cool, looking for layer forming on top. no layer yet. I slowly allow temp to rise, keep around 22C unless I see reaction signs, and cool to keep reaction slow. First problems are evident in pic 3. This solution is no more than 20C.

The reaction can go one of two ways from this point. Here is alternative 1 :

http://img141.imageshack.us/img141/8678/ngbad02pm7.th.jpg (http://img141.imageshack.us/my.php?image=ngbad02pm7.jpg) http://img177.imageshack.us/img177/3382/ngbad01xu7.th.jpg (http://img177.imageshack.us/my.php?image=ngbad01xu7.jpg) http://img292.imageshack.us/img292/5301/ngbad03yl2.th.jpg (http://img292.imageshack.us/my.php?image=ngbad03yl2.jpg) http://img292.imageshack.us/img292/6039/ngbad04gz4.th.jpg (http://img292.imageshack.us/my.php?image=ngbad04gz4.jpg) http://img185.imageshack.us/img185/6853/ngbad05ai2.th.jpg (http://img185.imageshack.us/my.php?image=ngbad05ai2.jpg) http://img88.imageshack.us/img88/402/ngbad06la1.th.jpg (http://img88.imageshack.us/my.php?image=ngbad06la1.jpg)

Too much gas is being released, so I add distilled water to double volume. I swirl and solution turns green. There is a separate layer on the bottom, which I keep. I pour off the green water. I add another two volumes of water and it turns blue. I swirl and dump off blue water. I add yet another amount of water which stays clear and I'm left with this bugger-green crap on the bottom. In the las pic you can see that it slowly bubbles. if I leave it to bubble, it will slowly shrink and disappear. Once I was able to keep flooding with water until I had one puny drop of milky white which I absorbed onto a piece of filter paper. I beat it with a sledge on a piece of 3cm thick steel and got nothing. As a last resort, I tasted it. It was so small of an amount that I could barely see it. It was sweet with an aftertaste that reminds me of acetone, or something like it. It immediately hit the back of my throat and I could feel it travel up into my head, sinuses. I can see why people complain about headaches, but for other reasons I am immune to the full intensity.

The other way it can go:

http://img411.imageshack.us/img411/577/ngtwo12dz5.th.jpg (http://img411.imageshack.us/my.php?image=ngtwo12dz5.jpg) http://img411.imageshack.us/img411/8448/ngtwo16hh7.th.jpg (http://img411.imageshack.us/my.php?image=ngtwo16hh7.jpg) http://img407.imageshack.us/img407/1717/ngtwo20py8.th.jpg (http://img407.imageshack.us/my.php?image=ngtwo20py8.jpg)

I keep it cool of course. I am able to swirl the solution and gas is released. The solution is yellow, a lot like white wine. It bubbles, and very quickly turns orange, then red, then black. It is fast enough that I am unable to capture the colors on camera. I can swirl more, release more gas, and color will return to the clear white wine color. Of course, it wants to go back to the black color. I don't have a picture of this, unfortunately, but at the moment that the swirling stops, I can see the yelow as the bulk of the liquid, but next to the oil layer on top, a blue hue right underneath, which turns clear, then to the yellow color. Quite colorful, I wish I could capture it on film. Maybe next time. Anyway, This reaction can go on for nearly two hours, releasing lots of gas. The final photo demonstrates that the gas released is NO, reacting again in air to make NO2.

I never allow temperatures to rise too high, never ever above 30C. I do a rapid cool if it hits 25C. I try to always keep it below 22C. I get no reaction at all if I lower the temperatures below 20C, not to mention 15C. Sulphuric is distilled battery electrolyte, never touched a real battery, fresh from box. Nitric is sulphuric/kno3 method. Glycerol is 99.5% or better. Water is distilled. Thermometer was verified accurate in the range of operation. Glass is all clean.

I should also mention, I have seen a runaway nitration from this procedure twice. If I walk away from an apparently temperature stable solution (to use bathroom or get soda, etc.) I came back and witnessed a violent vaporization of the solution, both times making a red mushroom cloud which would make a good movie prop for a genie coming out of a bottle. I don't walk away any more, and I keep it cool, cool, cool!

OK, guys, tear it up! Thanks

-----------------
EDIT #1
Acids are as "strong as possible", the sulphuric was boiled until fuming, so maybe 98%. Nitric is straight out of the h2so4/kno3 method, it is red fuming as in photo. Here's another pic of it. Strength not any more precise than that, sorry.

http://img338.imageshack.us/img338/7773/redfumingnitricay0.th.gif (http://img338.imageshack.us/my.php?image=redfumingnitricay0.gif)

Reactants are all by volume. Good point, Bert, thanks.
---------------------------------

[Bert]

You never mentioned the strengths of the acids involved. You do not specify if your ratios of reactants are by weight or volume.

[NGfan]

Yeah, and you may have too watery glycerin. Haha, I think you may have underestimated the ability of sulfuric acid to heat up when added to water. What happened to me when making my *small* tester portions, was that the excess sulfuric would heat up to such an extent that it would heat the NG up to it's decomposition point, whereapon it turned green and bubbled, much like yours.

The water never seemed that hot, it was just where the water and NG met.

Try making smaller batches, and also not leaving the NG and acids mixed together for too long. Add tiny bits of the NG to large amounts of water, and burn the NG to test it, rather than detonating it. (blue flame, but you should know that, after searching the forums so thouroughly).

You may also want to use the alternate method I wrote as shown on wikipedia.

Good luck.

[stupid939]

If you boiled your H2SO4 until it started fuming (I'm assuming from battery acid) you will only get around 55%. Read some of the threads on concentrating it, and you will have to boil it a lot longer. Then again, it may be your glycerin.

It would also be easier to measure out a known volume and then weigh it. Check your density and then look at the sulfuric or nitric acid chart on frogfot's site.

[The_Duke]

There are many threads already in which you could have posted this in…

The problem is most likely the homemade nitric acid. A large amount of nitrogen oxides in the nitric acid has a tendency to decompose sugar alcohols catalytically by oxidation. This is why white nitric acid is used and not red fuming. Small amount of nitrous oxide does not hurt, but large amounts can have a detrimental affect!

Bubble air through your nitric until clear or dissolve a small amount of urea in it and you should not have these problems.

If problems continue you can almost completely eliminate the nitric acid as the source of the problem and must therefore look at the other reactants as the cause of troubles.

[megalomania]

I also tend to lean towards the red fuming acid as the culprit. The standard reagent grade concentration, 70-75% I believe, is all that is required for this particular nitration.

The organic chem gods have not smiled upon thee this day :(

[Bert]

Time to do some more reading in the (many!) related threads.

You will note the common use of density to characterize acid strengths, and the frequent use of WEIGHT rather than volume in lab procedure descriptions.

There are also several descriptions of the methods to remove nitrous oxides from nitric acid on this site.

[LibertyOrDeath]

ASY: Sorry if this is a dumb question, but when you refer to the "H2SO4/KNO3 method," does that include vacuum distillation? Or did you try to distill the HNO3 without a vacuum? The reason I ask is because I've seen methods described that did not make use of a vacuum (e.g., the Improvised Munitions Handbook).

According to Home Workshop Explosives by Uncle Fester -- which, to my newbie eyes at least, appears to be a very good book -- vacuum distillation is necessary to make usable HNO3. He says, "Without the vacuum, a reddish colored product is made that is not very suitable for making explosives."

Regarding the H2SO4, Uncle Fester states that it should be concentrated to a density of 1.85 to 1.91 g/ml. He also frowns on acquiring concentrated H2SO4 by boiling down battery acid. Maybe professional-strength drain cleaner will give better results. I believe some have mentioned Liquid Fire in older posts on this board, stating it to be of high quality.

[nbk2000]

Fester is discredited, almost to the point of k3wL'ness, in regards to anything E&W related. And his drug related books are rather lacking in certain critical details. STRIKE is far better.

No, you don't need a vacuum for distilling nitric. In fact, you can make very high grade nitric by blowing air through it during the distillation process, which converts the NOx that would otherwise turn the NA red, into pure NA. :)

[LibertyOrDeath]

NBK: Thanks for that information.

Pardon the newbish question, but what is STRIKE an acronym for? I did UTFSE but couldn't find it ("strike" is too common a word, even when other relevant terms are included). Thanks again.

[nbk2000]

STRIKE was of The Hive, author of a book called 'Total Synthesis'.

http://www.amazon.com/Total-Synthesis-II-Strike/dp/096582912X/ref=sr_1_1/002-7953212-5872004?ie=UTF8&s=books&qid=1174250003&sr=8-1

[xenon24]

Making pure "white fuming NA" isn't as hard as it seems.

Vacuum distillation isn't as hard as many people think; it can be done at home with a shop vac,some pvc pipe, adn silicone sealer (or some other sealer). I made a vacuum distillation device and even several vacuum traps out of canning jars (airtight)...because if you don't run the air through vacuum traps first you'll destroy your vacuum.

Like NBK said, running air through your system can be done too, and it's probably easier.

[Evolutionist]

what did you distill with that set-up? I dont think its safe to distill a strong acid with plastic in the system.

Or do you mean you made a vacuum pump with the PVC pipe/shop vac combo?

[Flamethrowa]

It looks like you are having a runaway. I've never managed to get visible amounts of NO2 forming at ALL. I'd consider that a runaway.

What do you mean there is no reaction under 20C? I cannot quote the source, but I recall hearing that above 20C the formation of the mononitro- isomer is favoured over the trinitro-, so I keep the temperature as low as possible.

Personally I use a nitration mixture rather than mixed acids because I have not gotten around to distilling HNO3 yet. The nitration bath is prepared the previous day and chilled in the freezer to frigid -20C. My last synth involved 50mL of glycerin, half of which was added slowly with the flask in an ice-salt water bath. The temperature reached 10C, which is the upper limit of my comfort range. The entire RV was placed back in the freezer until the temperature reached 0C and then the rest of the glycerin added. No problems.

Perhaps the added mass of the extra ions helps absorb more of the energy than with mixed acids?

I still don't understand what you mean by not getting a reaction; my last batch had nice white goopy nitro coming out of solution before half the glycerin was even added and the temperatures were as I have said above.

All those colours are quite strange to me. Try the nitration mix method, use NH4NO3, I quite like it...though yields are most likely slightly less than with mixed acid.

[mike16]

Today, I made some NG to show Al Shreik Yerbuti, how the reaction should look like.

I used 200ml 98% H2SO4, 100ml 70% HNO3 and 50ml glycerine.
The glycerine was from the local store, and boiled down to remove any water.
Apon mixing the acids, temperature rose to 50 degrees celcius, after 15 mins of cooling, I started adding glycerine, 1ml at a time.
The temperature never rose above 20 degrees celcius.

It took me about 30 minutes to add all the glycerine, 15 miniutes after all the glycerine was added, the mix was poured into water and the NG collected.

After washing with bicarb, final yield is 50ml which is 79.g.

Here are the links to the pictures:

Mixed acids:http://i155.photobucket.com/albums/s300/kpppppk/Picture002.jpg

Glycerine:http://i155.photobucket.com/albums/s300/kpppppk/Picture006.jpg

Adding the glycerine:http://i155.photobucket.com/albums/s300/kpppppk/Picture007.jpg

Layer of NG on acids:http://i155.photobucket.com/albums/s300/kpppppk/Picture008.jpg

Another pic of layer:http://i155.photobucket.com/albums/s300/kpppppk/Picture011.jpg

Closeup of NG layer:http://i155.photobucket.com/albums/s300/kpppppk/Picture009.jpg

Top of NG/acid mix:http://i155.photobucket.com/albums/s300/kpppppk/Picture012.jpg

NG under water:http://i155.photobucket.com/albums/s300/kpppppk/Picture016.jpg

Drying the NG over H2SO4:http://i155.photobucket.com/albums/s300/kpppppk/Picture021.jpg

Fimished clear NG:http://i155.photobucket.com/albums/s300/kpppppk/Picture030.jpg

Edit: It is very important to vigorously stir the mix as soon as you start adding glycerine, or it will form a layer above the acid and NG.
Also stir the mix for 2 minutes or so after all the glycerine has been added, then let the mix sit for 15-20 minutes to let the NG form its layer.

[Al Sheik Yerbuti]

Many thanks to many suggestions. I have not had much time recently to investigate all of the different potential sources for failure that you have brought up but will bring you an update when I find out more. I did try one more synthesis in which I made the substance that I assume to be "red fuming nitric" into assumed pure white nitric by adding sufficient urea to whiten it. I filtered the leftover prills out of the nitric with a funnel and some glass cotton from insulation. Long story short, I had no signs of reaction other than a slight tendency for the solution to produce small amounts of heat upon addition of glycerol. I've bubbled pure oxygen through the red mix with good whitening results also. Further info to follow.

mike16: Excellent photos! I found them very informative. Obviously from your post, as easy as it was for you, I have some fundamental flaw in my process. There are four possibilities: three ingredients which could be either contaminated, diluted, or not even what they are supposed to be; and the process itself, such as contamination or outbounding of the thermodynamic (physical) process parameters; temperature, pressure, even time at state. You helped to clarify the fundamentals of correcting this process.

Flamethrowa: 1) I've had definite runaways on at least three occasions, where the whole solution has evaporated into a red mushroom cloud with volumes of many cubic meters. Maybe what I have in the pics is a "walkaway"! ;) 2) "No reaction", by that I mean there is no color change, no separation, no exothermy, nothing to give me any indication of a reaction even after extended periods of time. Until the temperature rises and then I get the runaway mushroom clouds. So, I began to keep the temperature higher (20 - 22C) and I get heat generation and can control the rate of reaction better. 3) I can no longer get ammonium nitrate locally. I used to get it for $5 for 50 lb. The last bag I had I used on my flower bed :( But thanks to McVeigh and Usama....

LibertyOrDeath: My setup for making nitric is described in detail in another post somewhere. I assume that, since the vessel is sealed and the temperature is elevated fairly high, that my process is conducted under a mild pressure, not a vacuum at all! 2) battery acid is straight from shipping box, never touched a battery. I can boil it down to 1/3 the volume at which point it fumes (different than steam) and turns golden yellow. Density is in line with expectations.

I'll keep trying and post when I track down the problem and have success.
-----------------------------
EDIT:
OK I tried again. I kept it really cool, 10C. I saw little signs of reaction again. I kept swirling occasionally and after adding all glycerol kept it cool, swirled occasionally, and after 15-30 minutes let the temperature rise slowly. At 22C it got hotter, fast. It began to make red fumes. I attempted to force back down the temperature and was able to stop its rise but not cool it. it may have hit 26C or so (I'm not positive) but certainly did not get to 30 for sure. I poured it down the side of a 1 gallon glass jug which contained 1/2 gallon of water. I swirled and had a separate layer on the bottom. As I swirled it dissipated, so it must have been only the acid layer. Damn. When the layer was dissipated fully, there were tiny pinhead-sized droplets on the bottom. I could guess that it is less than 1/10 cc. At least I got something...(Yea, right)

I don't know. I can make up 20cc of red nitric, or something like it, (whatever it really is) with a lot of work in a batch, in one day if I stay on it. It goes right down the drain with each failure. I'm sick of it. Maybe I'll try the KNO3 and sulphuric direct method. God, if I could only be sure what the.... Hey, my nitric must be somewhat good, I was able to make silver nitrate, and I had reasonable results making double salts... well, whatever. Thanks all.

[Flamethrowa]

Thought I'd post this here, since this thread seems to be fairly active. I seem to lose a noticeable amount of NG due to surface tension on the water/acid mix (after watering it down).

I'm considering adding some percentage of alcohol to the mix to lower the density of the water layer and break the surface tension. Since nitroglycerin mixed with alcohol or another solvent can be made to sink out of solution by adding water, I'm hoping that a small amount of alcohol added before decanting won't dissolve the NG but will help break surface tension and enhance the seperation layer. Any thoughts?

Also, Al Sheik, NG is soluble in concentrated sulfuric acid. I would tend to think that after the reaction, the amount of sulfuric remaining would be much less relative to the amount of water, however pouring the solution into many times its volume of ice cold water might help to get the NG to sink.

The delayed reaction you are experiencing troubles me. Sounds almost like the reaction starts spontaneously after a certain period of time...glycerin is known to form a layer on top of the acids and then quite suddenly mix resulting in a runaway. Though I know you are swirling the mixture. Perhaps try physically stirring it.

After all the glycerin is added, and perhaps after a short period of time, the solution should be able to return to room temperature and above since no further reaction can happen.

[JouMasep]

xenon24,

I must confess that I am utterly bewildered by the brief explanation w.r.t. your suggested "vacuum distillation" setup.
“it can be done at home with a shop vac,some pvc pipe, adn silicone sealer (or some other sealer). I made a vacuum distillation device and even several vacuum traps out of canning jars (airtight)...because if you don't run the air through vacuum traps first you'll destroy your vacuum.”

I carefully considered the possibility of a “joke”, but no, your post was done on March the 19th, -not on 1st of April.

But I could be wrong, ‘spent all that money on my new rotary vane pump for nothing –damn, should’ve read you post first!

By the way, in case of a power failure, use a manifold, several non-return valves and the help of some of your mates. Promise them a supply of high explosives if they are willing to orally suck the hell out of it.

I promise you that the vacuum thus attained will be even better than the shop vac.

Anyway good luck with your endeavours, and don’t spare the liquid nitrogen in your vacuum traps –we would not want any of the nitrous vapours sucked into your dad’s Black & Decker shop vac wouldn’t we now? (Goes for your mates' respiratory tracts as well)

There may not be much of a vacuum to “destroy” in the first place, but it will rust the hell out of it.