10-11-04 22:46
No 535478
This is a fun reaction that may be of use in the production of anhydrous ammonia.
Everyone knows dimethyl carbonate, right? Useful alkylating agent, etc? Well, one method of making it works like this:
H2N-CO-NH2 + HOCH2CH2OH --> CO(OCH2)2 + 2 NH3
CO(OCH2)2 + 2 ROH --> HOCH2CH2OH + CO(OR)2
Well, this suggests that by heating anhydrous ethylene glycol with urea, one will obtain anhydrous ammonia. Just use the reaction above. I will post some papers on this process shortly. The advantage of this method is that there's no water produced, as in the standard ammonium salt neutralization, and all the ingredients are cheap.
The cyclic carbonate produced may also have some use. For example, if pyrolyzed, it may yield ethylene oxide.
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(Hive Addict)
10-11-04 22:55
No 535480
I suppose you mean dimethylene carbonate aka ethylene carbonate, not dimethyl carbonate? Of course, it would be quite acceptable if making dimethyl carbonate was that easy...
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(Wizard Master)
10-12-04 03:32
No 535509
Anhydrous ethylene glycol is not avaliable commercially and therefore is not easy to obtain.
Urea can undergo a decomposition reaction to produce NH3 + biuret + cyanuric acid near it's melting point of 132 oC. And urea is hyrated. Eg. urea.2H2O
The advantage of this method is that there's no water produced, as in the standard ammonium salt neutralization
(NH4)2SO4 + Ca(OH)2 =Heat=> 2 NH3 + CaSO4 + 2H2O
The 2 NH3 is passed through a drying agent to ensure completely anhydrous.