NERV - 25-3-2003 at 12:46
I was crusing Rhodiums web site for useful chemical information when I came apon this. I was planning to build this when I realised that I didnt have any calcium oxide, or soda lime for the drying tower. I was wondering if I
could replace it with anhydrouse MgSO4 I am pretty sure that it would be fine, but better safe than sorry.
Mumbles - 26-3-2003 at 09:33
I don't see why it wouldn't be fine. The drying agent is just that, only a drying agent. I don't believe ammonia reacts with
MgSO<sub>4</sub> either so I doubt you'd have a problem. I'd still wait for someone else's answer though, seeing as how
I'm not completely sure
vulture - 26-3-2003 at 15:27
CaO does not only absorb water, but also CO<sub>2</sub> from the air.
Also, from personal experience, MgSO<sub>4</sub> is nowhere as hygroscopic as other drying agents like CaCl<sub>2</sub> or
CaO.
Marvin - 27-3-2003 at 10:14
MgSO4 is pretty good as a drying agent, but its quite slow. I doubt theres much to choose between total water between that and CaCl2, but its much
better in terms of water vapour pressure remaining. Compairing the two is pretty academic anyway becuase CaCl2 cant be used for this (forms ammonia
addition product).
I doubt CO2 will be much of a problem.
Anhydrous ammonia isnt in the ammonia solution catagory of stinging eyes and shortness of breath, its in the pulmonary edema and die catagory if
theres a release of it (lungs fill with fluid), hense the paranoid comments about enough dry ice.
Id be inclined to not bother with weak ammonia solution in the first part of this process, just use an ammonia fertiliser like ammonium nitrate
(supposed to work best for this application). I understand ammonia freezes a little above the temperature of the dry ice/acetone cold finger, so Id
be inclined to run this fairly rapidly.
Very clever fellow that Eluesis, anyone know offhand if hes still in prison?
NERV - 27-3-2003 at 12:15
Well I am not to terribly worried about how fast the MgSO4 takes the water out I was planning on just re-bubbling the ammonia gas through water to
make a concentrated ammonia solution. I could probably just skip the whole drying tower since I don't need anhydrous ammonia. I think I will
consider the use of NH4NO3 as I have a lot more of it in storage then I do NH3, plus if it was anhydrous I could almost defiantly skip the drying
tower. Ill make the anhydrous ammonia when I get my dry ice maker. Hopefully that will be sometime in the near future.
NERV - 27-3-2003 at 12:36
I am not sure if I am right, but I did the reactions in my head real quick, and it doesn't look like NH4NO3 with NaOH would work as you would get
NO3 produced in the reaction to. Ill have to check my local supermarket to see if they carry NH4HCO3. Although I am unsure of what purpose they would
have it for.
drying NH3 (ammonia) gas
Organikum - 27-3-2003 at 17:39
No CaCl and no MgSO4 for drying.
Why? Just try it.
The recommended drying mix is NaOH and CaO, if no CaO is available NaOH alone works.
drying agents download:
drying agents 1
drying agents2
CaCl reacts, MgSO4 soaks H2O up but with the NH3. You get stinky MgSO4.
Eleusis procedure is useful when you can get only 3% ammoniawater and nothing else. I know no place on earth where someone can´t buy cheap and by the
50kg bag ammoniasalts containing fertilizer. This is a better source or salmiacstone (for cleaning soldering irons for example) is NH4Cl -
ammoniumchloride. By dripping a little water on a NH4Cl/NaOH mix a reaction starts freeing the ammonia from it´s salt. Alternative if 28%
ammoniawater is available you can drop this on a large excess of NaOH and get ammonia.
The cooling setup of Eleusis is poor and won´t work. A precooler (H2O-ice/NaCl) before the drying tower is recommended.
ORG 