John paul III - 12-7-2018 at 12:14
As I'm going through my "ammonia to nitric acid stage" as every amateur has to, I present you with an idea:
Since the main reason why the oxidation product is nitrogen is the reaction xNH3 + xNO -> N2 + H2O, we could try absorbing nitric oxide as soon as
it's produced into NaOH. Ammonia burns poorly; for sustained oxidation it needs a constant ignition source like paraffin needs a candle knot. If NaOH
was heated to 300-400°C we could be assured that NO is produced only in close proximity to the absorbent and that the rate of 4NaOH + 6NO ->
4NaNO2 + N2 + H2O Is high. Then NO would be released from NaNO2 and oxidized and absorbed into water in absence of NH3. Is this idea worth anything?
Alkoholvergiftung - 12-7-2018 at 12:34
Hello.
There are old patents of ammonia oxydation on Alkalien survaces like KOH or CaOH.If there are contact metals are pressent like copper or silver, iron.
Or if you have molten NaOH and you bubble NH3 and O2(throught different pipes) inside it will form nitrate and nitrite and 0,5 or 0,7V like an fuel
cell.Sodiummanganit or Magnesiumplumbate works also. It react with sodiummanganit and decompuse but you only get an yield of 60% nitric acid.There is
somewhere an patent of Dr. Hoffmann he oxydize ammonia on CaOH with 0,5% copper pressent around 250 degree or more (it must only be under the melting
point of the nitrate).He stated that all of the ammonia reacted to nitrate over amide to nitrite than nitrate.
John paul III - 12-7-2018 at 13:04
Interesting, is the hoffmann patent in dutch/german? Did he use Cu ions or metal?
Alkoholvergiftung - 12-7-2018 at 23:39
It is in German. The Ions are not neccesary but they Speed up the Reaktion.The best metal he wrote is Nickel.He wrote that you can use it as metal
like for the heating element or the container wals.Or better as very fine powder "when you pur of the CaOH little bit of coppersulfat solution." I
have his experimental work on my Computer but i dont have any more the link where i have downloaded it.The name of his work was "Über die oxydation
von ammoniak am kalk zu kalksalpeter".
https://vdocuments.site/documents/ueber-die-oxydation-von-am...
found the side.
[Edited on 13-7-2018 by Alkoholvergiftung]
John paul III - 17-7-2018 at 04:47
Thank you, I just noticed you found the link!
Alkoholvergiftung - 17-7-2018 at 05:41
Np. I think his work is genuine. Because kuhlmann wrote 1838 the same Effekt with limestone soacked in pottash or KOH solution he used no katalayst
and only 100 C Temperatur. After an week an greater amount of saltpeter crystellized out, Dumas had the same Outcome. Oh and it was Imide nitrit
nitrate Reaktion.
When you search for direct ammonia combustion Georg Kassner. Invented an katalyst on bariummetaplumbate and bariummanganat double salt Basis. They
wrote it worked at 500C and is good for smaller plants because it oxidzed direct to NO2 so there was no oxidation Tower needed. (around 1922).