Sciencemadness Discussion Board

Small scale production of H2SO4 in the amateur lab

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blogfast25 - 19-3-2023 at 05:50

Quote: Originally posted by RU_KLO  


Which one should I try to buy? or just try to buy Ba(NO3)2.


The latter. Or BaCl2.

Or: react Desert Rose with Al powder:

BaSO4 + 8/3 Al ==> BaS + 4/3 Al2O3

Then leach out the Ba2+ with strong HCl.

[Edited on 19-3-2023 by blogfast25]

blogfast25 - 19-3-2023 at 05:53

Quote: Originally posted by Rainwater  
A less sensitive test
2NaCl + H2SO4 → 2HCl + Na2SO4
HCl + NH3 = NH4Cl

Again br8ng the solution to 120c to remove HCl.
Then close by place a container of ammonia, add salt(NaCl) to the H2SO4 solution and look for white smoke(NH4Cl).


That's not SA specific. Assuming the test works it will work for almost any acid. But it's not a bad idea...

[Edited on 19-3-2023 by blogfast25]

Twospoons - 5-12-2023 at 14:08

I stumbled across this patent https://patents.google.com/patent/US20040234441A1/en describing the conversion of ammonium sulfate to ammonia and sulfuric acid. I know patents can be a somewhat dubious source of information but if it works it would be a reasonably cheap and simple method. The temperatures are reasonable and it doesn't involve SO3. It does probably require accurate temperature control though.
Quote:

The present invention concerns a method for manufacturing of ammonia gas (NH3) and sulphuric acid (H2SO4) characterized wherein ammonium sulphate ((NH4)2SO4) is mixed with concentrated sulphuric acid, and by heating the mixture to a temperature above 235° C., whereby ammonium sulphate is melted, and thereafter by heating the mixture to above 280° C. but below the boiling point of concentrated sulphuric acid (290° C.-320′), by which ammonium sulphate is decomposed into ammonia gas and sulphuric acid liquid simultanously, and where the produced sulphuric acid during the reaction time is mixed ideally with the concentrated sulphuric acid from the initial basis mixture.
[0011]
By this method it is achieved to decompose ammonium sulphate to a fully extent into ammonia gas and sulphuric acid liquid, where the ammonia gas during processing is evaporated and separated out from a rest solution consisting of sulphuric acid.

clearly_not_atara - 5-12-2023 at 15:02

^In brief, I think this patent is wrong, but based on what I've read before about ammonium sulfate decomposition, similar reactions do exist. The thermal decomposition sequence is, roughly:

ammonium sulfate + heat >> ammonium bisulfate + ammonia (g)

ammonium bisulfate + more heat >> ammonium pyrosulfate + water (g)

ammonium pyrosulfate + lots of heat >> SO2 + H2O + N2 (undesirable)

So if you add ammonium sulfate to sulfuric acid, you will primarily get ammonium bisulfate, which undergoes the thermal decompositions described above. But you can react ammonium bisulfate with sodium or potassium salts to get the mixed sulfate, which then releases ammonia and water to give sodium or potassium pyrosulfate, eventually SO3. But this involves generating SO3 at a very high temperature, which is what most people would strongly prefer not to do.

However, you could use ammonium bisulfate itself as a reagent, e.g. rxn with bromide salts to release HBr. In this rxn, the bisulfate is about a million times more acidic than the ammonium, so HBr should be evolved more easily than NH4Br. Ammonium sulfate may be cheaper or easier to get than bisulfates, so this could be convenient sometimes.

LookingForAnswers - 13-6-2024 at 21:16

Which method is better to make a catalyst bed? nh4vo3 or salts of vanadium organic acids? I bought v2o5 right away, but I read somewhere that impurities in the commercial v2o5 reduce the performance of the final product. Is it true ?
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