Hydrazine sulfate is placed into liquid ammonia forming ammonium sulfate and hydrazine. The ammonium sulfate is filtered out and the ammonia is
allowed to evaporate leaving pure hydrazine (99%+).
This should be more convenient than using sodium or potassium hydroxide and high temperatures to produce hydrazine.Oscilllator - 4-8-2015 at 16:38
Safer, yes. More convenient? To just about everybody on this forum, no. Liquid ammonia is almost impossible to buy because of its uses in drug
manufacturing and building a cryocooler to liquify the ammonia, while possible, is much more difficult than some of the other methods available.
For example a slurry of Ca(OH)2 and hydrazine sulfate should produce the more insoluble calcium sulfate and free hydrazine. This method produces
dilute hydrazine, but anhydrous hydrazine is very dangerous in any case.Magpie - 5-8-2015 at 08:42
This looks like a better route to concentrated hydrazine hydrate, ie, the use of xylene to remove water by distillation:
Leonid Lerner, in his book, says he used alcohol for concentration but does not give details.
I'm not messing with pure hydrazine - sounds like a good way to blow yourself up!
From personal experience, anhydrous hydrazine by itself is really not that bad at ambient conditions. I would distil it under reduced pressure, but
pure hydrazine is certainly no shock-sensitive explosive.
Just don't mix it with VOCl3 (vanadium oxytrichloride)! That was one test I did remotely and the result was a detonation. Back then I was
testing cold colored smoke producing compounds for the Canadian Forces and VOCl3 was a favourite; but I digress.
I found anhydrous hydrazine mildly irritating; very much like ammonia. As long as it is pure and not contaminated by heavy metals anhydrous hydrazine
is stable. Of course, the problem are the many materials that it can form hypergolic mixtures or shock-sensitive explosives with.annaandherdad - 7-8-2015 at 14:40
building a cryocooler to liquify the ammonia, while possible, is much more difficult than some of the other methods available.
It's easy to make 100ml or so of liquid ammonia with dry ice. It's also easy to scrub the excess ammonia with an inverted funnel over water so almost
no ammonia gas escapes. I don't know how much hydrazine the OP wants to make, though.
