rikkitikkitavi - 27-11-2002 at 13:31
I have found a patent :US3364202
describing a method of decomposing
NH4HSO4 into H2SO4 and (NH4)2SO4 by extraction by MeOH(preferably) or EtOH.
Not taken in account various problems of separation, corrosion e tc , the final product is a composition of (after MeOH is evaporated)
~4 % H2O, 80 ~% H2SO4 and the rest is (NH4)2SO4.
My question is the following:
Ideas for separating out the (NH4)2SO4 from the acid?
frezzing f e x ?
Would it interfer in f e w nitration reactions?
/rickard
Polverone - 27-11-2002 at 19:28
Not having experimented with it myself, I don't know if ammonium sulfate can easily be frozen out of sulfuric acid. The purification method that
immediately comes to mind is reduced pressure distillation, but this requires glassware and would be energy/time-intensive. As far as nitration goes,
my (quite possibly mistaken) instincts say that the contamination won't be a problem. I might expect the reactions to take longer, though, given the
dilution.
Say, how does this compare to the other methods you've looked at? Is methanol inexpensive and readily available for you?
EtOH
BASF - 28-11-2002 at 06:35
I don´t know how much more unfavoured the use of etOH is(MeOH would be rather hard to get here in europe), it immediately comes to my mind, that
(NH4)2SO4 is insoluble in etOH so compared with MeOH, which is well known to be one of the few organic solvents also dissolving anorganic substances
and salts to some extent, there would be less or no (NH4)2SO4-impurities.
HLR
Marvin - 30-11-2002 at 12:46
Ammonium sulphate wont be present as an entity. If any salt freezes out it will be ammonium hydrogen sulphate. The presence will probably cripple
its use for nitration as much less primary acid remains. If you added nitric acid to it and heated its possible nitric acid, nitrogen, nitrous oxide
would come off but its questionable how safe this would be to do. Adding a nitrate salt and distilling the nitric acid would probably be safer, and
at least provides a use for the product.
snop - 2-12-2002 at 12:55
Why meking H2SO4 witch HNO3 and NH4NO3
IN poland 1000ml H2SO4 cz.d.a cost 12PLN or cz. 8PLN , 3dolars or 2 dolars ; - )
vulture - 2-12-2002 at 14:56
First of all, this thread is about making H2SO4 from NH4HSO4. It has nothing to do with NH4NO3 or HNO3.
Second of all, I can buy my sulfuric acid very cheap and easily also, but it's of no use because 90% of the members here doesn't live in my country!
rikkitikkitavi - 3-12-2002 at 10:45
gee since I live in south of sweden , only a 45 min drive to the town where the ferries to poland leaves (over the baltic sea) maybe I should take my
car over, fill it with cheap alcohol, cheap sulfuric acid and cheap women 
I get the acid from my company for free, so I beat you all. As much as I need , since we consume > 80 tons /day.
But for my own interest in chemistry and the challenge I want to recreate the acids the fertilizers where made of from the beginning, a sort of
chemical "reverse engineering".
Anyway, back to topic.
The patent shows one way, but the other patents describing a HNO3-catalyzed liquid phase oxidation of SO2 seems much more feasible. This method needs
large amounts (4-5 times NH4HSO4) recycled. Plus that the generation of NH4HSO4 from (NH4)2SO4 creates lots of toxic NH3 which has to be dealt with,
thus another process.
And most important, it doesnt give pure acid.
But all kinds of double salts with (NH4)2SO4 and H2SO4 and H2SO4. Can probably be used to make HNO3 together with NH4NO3! (recreate NH4HSO4).
Theoretically I prefer the other method.
But by no means stop this discussion. Someone might be having a great idea to put in.
/rickard