Sciencemadness Discussion Board

Catalytis AN decomp.

Adas - 1-10-2011 at 09:37

Hello, my friend wants to know if there is any catalyst to decompose AN and get N2O.
Thanks :)

simba - 1-10-2011 at 10:35

Nitrous oxide is most commonly prepared by careful heating of ammonium nitrate, which decomposes into nitrous oxide and water vapor. The addition of various phosphates favors formation of a purer gas at slightly lower temperatures.

According to wiki, phosphates may help somewhat.

Endimion17 - 1-10-2011 at 13:39

Just be careful and don't heat more than few grams spread in a flask as there can be a heat buildup and runaway reaction.
For example, don't heat half a kilo in a spherical container.

Adas - 1-10-2011 at 21:52

Quote: Originally posted by Endimion17  
Just be careful and don't heat more than few grams spread in a flask as there can be a heat buildup and runaway reaction.
For example, don't heat half a kilo in a spherical container.

I was heating some AN in test tube before :D After a massive heating, it ignited, but when I stopped heating, the flame has also stopped :)

Endimion17 - 2-10-2011 at 05:27

Quote: Originally posted by Adas  
Quote: Originally posted by Endimion17  
Just be careful and don't heat more than few grams spread in a flask as there can be a heat buildup and runaway reaction.
For example, don't heat half a kilo in a spherical container.

I was heating some AN in test tube before :D After a massive heating, it ignited, but when I stopped heating, the flame has also stopped :)


Pure, reagent grade ammonium nitrate doesn't burn, but it can seemingly ignite if there are earth alkali nitrates inside. That happens when you have AN extracted from fertilizer prills.
Not only is that more dangerous because earth alkali nitrates stay solid at AN decomposition temperature and provide hotspots if stuck to the vessel, but it can also give impure nitrogen(I) oxide, with more nitrogen(IV) oxide.

Even half of a large test tube of pure AN is reasonably safe if heated properly because its volume to surface ratio is OK. But spherical, larger containers are able to produce hotspots and detonate. It's a small chance, but the consequences can be devastating.

Neil - 2-10-2011 at 05:31

Try searching the forum... the threads are there...