Oxirane
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Ammonia from urea
I cannot find ammonia solution anywhere so I figured out ways to produce it. Ammonium chloride and NaOH and AN are evident sources but neither are
available OTC. Ok AN is as fertilizer but nearest farm shop is nearly 80km away and I dont need 40kgs of impure stuff.
So I read around that urea will release ammonia by couple of means. One is to heat it so it will decompose, but this will release only part of it.
Another way I heard is alkaline hydrolysis. Both NaOH and Ca(OH)2 are available to me and urea is sold in 1kg bags otc. Does this route work?
CO(NH2)2 + Ca(OH)2 + H2O = CaCO3 + 2 NH4OH
2 NaOH + CO(NH2)2 + H2O = Na2CO3 + 2 NH4OH
So the reactants are mixed in water and the mixture/solution is slowly brought to near boiling and ammonia will be released as gas.
I have made HCl with H2SO4, NaH2SO4 and NaCl with gas apparatus so I'm experienced with making solutions. Just that this would work.
[Edited on 21-9-2014 by Oxirane]
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TheChemiKid
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Possibly this would happen as well, but I can't find any proof of it: NaOH + (NH2)2CO -> NaOCN + NH3 +
H2O
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aga
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The experts are probably all sighing and wondering why they bother.
I'm a noob, and have seen this asked several times.
The really experienced guys would probably be more interested if you were asking Why your Attempt at making Ammonia from Urea failed, or didn't make
as much Ammonia as expected.
Try a few grammes in a test tube with Sodium and then Calcium Hydroxide and see if it smells like ammonia.
Get as far as you can by experimenting.
You'll learn more, and the experts would then (probably) jump in and tell you how to do it better.
[Edited on 21-9-2014 by aga]
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Oxirane
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I know for a fact that sodium carbonate and urea will release the one excess molar of ammonia when heated to fuse into sodium cyanate, which can be
further reduced to sodium cyanide with carbon, because I've done this a few times. So getting ammonia gas via pyrolysis can be done. Since all of the
reagents are quite cheap, I will use this route if necessary and dump the excess cyanates.
I performed some searches on this topic as early as few years ago, but found no conclusive evidence on how this would work, and since I've got many
projects going on, I wouldn't want to read those 100+ page behemothic topics about random hydrolysis reactions to discover some well hidden phrase
which dictates the simple rules of this. So apologize my "laziness", I just wanted to ask help, because someone certainly knows about this, or at
least by not going through the trouble of explaining it the n'th time by just showing the right direction where to look. 
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aga
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Reading is inevitable,and generally valuable.
Oh. I just UTFSE and found this :
http://www.sciencemadness.org/talk/viewthread.php?tid=9127
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Oxirane
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Oh well, there's some discussion. Many thanks!
Franklyn wrote in his post at page 1:
"If you're going to all this trouble to decompose urea by heating you may as well
obtain 100% of theoretical recovery of ammonia by mixing with strong Alkali in
water. H2N.CO.NH2 + Ca(OH)2 -> CaCO3 + 2NH3 . The lime formed can then be
heated itself to drive off the CO2. Much simpler and neater overall."
This is something I actually remember seeing somewhere before. Most of the topic concerns of making DRY ammonia gas and is about CaCl2 adduct. Might
been this topic, anyways, gotta make some tests with it. The reaction itself seems balanced.
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blogfast25
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Quote: Originally posted by Oxirane  | | I cannot find ammonia solution anywhere so I figured out ways to produce it. Ammonium chloride and NaOH and AN are evident sources but neither are
available OTC. |
Any ammonium salt will give ammonia with a strong alkali, noy just NH<sub>4</sub>Cl. Ammonium sulphate e.g. is very OTC: garden centres
for instance...
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Oxirane
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Yes I know it, but this depends on the country you live on. Here all fertilizers are sold as mixtures with some exceptions, because of anti-terror
legislation. Ammonium sulfate is one unofficially-listed fertilizer because it can be readily mixed with calcium nitrate - which is on an official
list - to double displace it to very easily purified mixture of calcium sulfate and ammonium nitrate.
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