Hoffmann-LaRoche
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Cheap H+ from ammoniumsulfate-fertilizer
For those countries, H2SO4 is hard to get, or expensive, NH4HSO4 could be considered as working in many reactions that call for a strong H+ source as
it (nearly) fully splits off its hydrogen ion.
equation: (NH4)2SO4 > (heat) NH4HSO4 + NH3
what do u all think of this?-HLR
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rikkitikkitavi
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i think it can be a useful complement.
HSO4- is NOT a strong acid in aqeous solution. 1 M solution has a pH about 1,5 , meaning only 2 % of the HSO4- is protolyzed. However in some
reactions this doesnet matter, f e x
Ca(NO3)2 (aq)+ NH4HSO4(aq) => HNO3(l) + CaSO4(s) + NH4NO3(aq)
neither does it have the water absorbing potential of pure H2SO4 and high boiling point. It can be used as a cheap H+ source for dissolving metalls ,
as earlier proposed.
The manufacturing of large amounts shouldnt be underestimated , since NH3 is formed. And this is very toxic.
/rickard
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Hoffmann-LaRoche
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You may right if u mention NH4HSO4 not really to be a strong acid....
Ive also thought of methods to convert it to the more desirable NaHSO4 or KHSO4, but so far, i had no idea of how that would be possible.
Mentioning the toxicity of NH3, i dont agree with u because NH3 has an intensive smell and this is why intoxications are very rare in practice..
Furthermore it is possible to dissolve the NH3 in cold water which would also be more economic.
Greetings, HLR
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rikkitikkitavi
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melting NH4HSO4 + Na2SO4 to produce sulfuric acid.
NH4HSO4 + Na2SO4 => NH3 + NaHSO4
(at 300 C)
2 NaHSO4 => Na2S2O7 + H20
(at 400 C)
Na2S2O7 => Na2SO4 + SO3
(at 500C)
this method of making sulfuric acid is patented-( german patent 1.151.492)
search for ammonium bisulfate
at www.uspto.org
Also
NaCl+ NH4HSO4 => NaNH4SOe + HCl
(at 120+ C)
could perhaps work with nitrates to, but with lower yield since HNO3 decomposes.
The thermal decompostition of NaNH4SO4 is not easy. In the patent above it is described how the heating of the molten salt is provided with
superheated steam, which also stirs the melt and quickly removes any NH3, since the following reaction
NaNH4SO4=´NaHSO4+ NH3 is a equlibrium
thats all for me folks!
/Rickard
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Hoffmann-LaRoche
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sounds like the holy grail for cheapskates
Na2SO4 could be replaced by K2SO4 in that reaction, i guess.
Then K2SO4 could be made out of calcium sulfate dihydrate(waste and cheap soil) and pot ash, following the equation CaSO4 + K2CO3 > CaCO3 + K2SO4.
This process will run to the right, as the following solubilities show: pK(solubility product) 4,3 for CaSO4 whereas 7,9 for CaCO3 at 18-25°C
Greetings, HLR
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rikkitikkitavi
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exactly the same conclusion I came to for a few months ago, while searching for a method of making HNO3 from only fertilizers, and no exotic synthesis
routes.
(NH4)2SO4=> NH4HSO4 + NH3´(@120-200 c)
aq
NH4HSO4 + Ca(NO3)2 => NH4NO3 + HNO3(l) + CaSO4(s)
And a synthesis route to H2SO4 then too
Major problem is the LARGE amounts of NH3 formed. I can see three ways of solving this
1) scrubb the gases, get a aqeuos solution of NH3
2)solution by dilution
3)burn the shit
My idea was to set up a LPG fueld heating oven for the decomposition, and using NH3 riched air as combustion air.
Drawbacks: Risk of explosion. NH3 IS combustable in air, however heat of combustion is not enough to sustain reaction, but it can explode if prime
enough,.This is a major pain in the ass for HNO3 plants,
sofar I lack the space and time to proceed, however if anyone is willing to proceed I am always avilable for discussion.
/rickard
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rikkitikkitavi
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edit ! edit! edit!
FYI:
NaHSO4 reacts funny in alcohol:
Na2SO4 has a very low solubility, thus
a solution of warm NaHSO4 in water mixed with alcohol preciptates Na2SO4:
left is a liquid mix of H2SO4 + EtOH!
they form EtHSO4 of course , which decompose into ethene or diethylether upon heating, leaving dilutied H2SO4,
Just for the fun of knowing it.
/rickard
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Hoffmann-LaRoche
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toxicity might not be the problem
if you mind about the toxicity of NH3, i can only say i made huge amounts of NH3 outdoors in the garden...
It was from the reaction of making Ca(NO3)2 from CaO and NH4NO3.
I had no problems with the ammonia gas, i just held my breath when i came to check the stage of the reaction, and it seems that the hot NH3 gas, as it
is also lighter than air, ís not a very toxic gas to plants.....i earlier discovered that NOx and SO2 ARE.....im sure its not such a problem, if it
would be made outdoors.
So it would be more an economical question whether to make a solution of NH3 in cold water(water easily sucks huge amounts of NH3 gas, remember the
"ammonia spring"- experiment, which is described in many experimenting books), or wether to burn the gas.
I really stick to this ideas of making HNO3, H2SO4 and HCl out of fertilizers and waste substances cause they simply would be unbeatably cheap, and
just more when i think of the horrible prices here..(1L conc.H2SO4 costs about 7€ and 1kg conc. HNO3 about 21€!! at the best source here)
HLR
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vulture
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If one would manage to burn the NH3 then you've got nitrous oxide... What can one make with nitrous oxide???
Indeed, two bangs for one buck, if I may say so...
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Hoffmann-LaRoche
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burning would only yield N2 and H2O.
U would have to use a platinum catalysator and an excess of oxygen at 700°C(at least thats the magnitude..) so this would be a rather complicated
project..not worth trying it, in my opinion.
-yields are low and the danger of explosion always exists, especially when using pure oxygen and not air.
I think the best thing to do with our NH3 would be to make a solution, as this is still better then just blowing the gas away.
HLR
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