I’ve spent a lot of time researching energetic synthesis and have concluded that ETN is the best energetic for me in terms of availability and cost
of reagents and performance, when I need something more brisant than ammonium nitrate.
The only reagent that is somewhat expensive for me to obtain is quality sulfuric acid so I was wondering if there is a practical and economic way to
recycle it from an ETN synth. I apologize if this has been asked before. I tried the search engine but I’ve had issues with finding information on
this site in the past.mackolol - 27-4-2020 at 01:50
There is no practical and economic way to recycle sulfuric acid from reactions.
Just look for H2SO4 properties and you'll know why....
You could conver it to copper salt and then do electrolysis of its solution followed by evaporation of water on high heat, but it's nowhere economic
neither practical:
Kind of looks like a fun project. karlos³ - 1-5-2020 at 20:26
Just stock it in useful amounts.
The effort you need to put into making it, and the cost and associated dangers aren't worth it.
And even if you try, you would still haven't concentrated acid(see glover acid, I think it had a bit above 80% usually), and you would have to
concentrate it further.
If you really attempt this, at notable amounts, expects lots of holes in your lab coat.XeonTheMGPony - 11-5-2020 at 04:02
And massive bills.
It is easier to make a chemical plant to produce it then it is to recover sadly, I looked in to a great many ways and it just isn't practical in any
way, first you need to remove the nitric acid, then you need to drive off several liters of water, then distill it.
Microtek - 13-5-2020 at 08:20
To everyone wondering why OP doesn't just buy large amounts of concentrated sulfuric instead of recycling:
In the EU, sulfuric acid above ca. 50% concentration is illegal to buy for private citizens. Maybe something similar is true elsewhere.
This is why I prefer using pure fuming nitric acid for PETN, rather than mixed acids (I realize you are speaking of ETN). Industrially, you would
likely separate the produced ETN from the mixed acid without crashing in ice water, to avoid having a large amount of water to distil off.
Unfortunately, this can be a challenge unless you have access to a fritted glass filter (you can get them in China at reasonable prices and in decent
enough quality).
Then the waste acid would be distilled to collect as much HNO3 as possible and to drive off the remaining water, and also to destroy traces of ETN. Be
aware that this step WILL LEAD TO FUME-OFF OR EXPLOSIONS. Don't attempt this in ordinary glassware, a properly designed reactor is required to do this
safely. I don't think it is impossible in the amateur lab, but I would recommend experimenting with a WFNA process instead. It is much easier to
reconcentrate the sulfuric if it doesn't contain any energetic material.
Having said that, I did once experiment with recycling sulfuric from NG synthesis by adding small amounts of hydrogen peroxide to the spent acid in
order to oxidize traces of NG by way of piranha. It bubbled slightly but didn't react violently, however, I will not guarantee it won't run away if
you try it...
[Edited on 13-5-2020 by Microtek]Herr Haber - 14-5-2020 at 05:59
In the EU, sulfuric acid above ca. 50% concentration is illegal to buy for private citizens. Maybe something similar is true elsewhere.
[Edited on 13-5-2020 by Microtek]
I have bought a lot of 90%< H2SO4 as a private citizen in EU, I don't know what are you talking about...
Maybe in some countries.Microtek - 14-5-2020 at 10:56
I don't know if this is fully ratified or fully implemented yet, but in my country, it is no longer legal to buy nitric in concentrations above 3% or
sulfuric above 50%.
This is one reason that I have worked on developing lab scale process equipment for the production of these two chemicals.Herr Haber - 14-5-2020 at 11:10
UK is a bit ahead of the rest of Europe in that regard.
But there's no real logic or even respect of the existing laws.
I am not supposed to be able to get 35% H2O2 anymore but the same company (not a chemical supplier, more of a drugstore) still sells it to individuals
along with 96% H2SO4 and many other industrial chemicals that could be misused.
If you want 69% nitric acid a company number and a declaration of intention is enough. They dont sell Borax to individuals anymore and ask for the
same paperwork as for HNO3.
