xxxxx - 6-10-2007 at 05:47
i was wondering if it might be possible to produce HCN by passing propane and ammonia through a conventional automobile catalytic converter which was
heated to about 600C either by electicity or by a propane oven. then the HCN could be captured by being passed through a solution of NaOH or Ca(OH)2.
Antwain - 6-10-2007 at 07:38
Can you suggest a reaction mechanism / scheme for that?
Sauron - 6-10-2007 at 08:47
This sounds like a recipe for disaster. The only thing worse than HCN is hot angry HCN. HCN loves to explosively polymerize. A number of plants making
or utilizing HCN have gone up that way with considerable loss of life.
The good news is I do not think you would likely get any HCN to start with. Automotive catalytic converters are not designed for this purpose.
I suggest you read the usual suspects (Ullman, Kirk-Othmer) on industrial HCN production, then if you are still bent on stroking your deathwish you
will have a better idea how to go about this.
But I believe others have elucidated methods for producing alkili cyanides that do not require gaseous HCN at any stage. UTFSE.
JohnWW - 6-10-2007 at 17:28
Who do you want to kill with such a large quantity of HCN, Xxxxx? Do you want to use it in Afghanistan or Iraq or something as a war gas?
As for the "explosive" polymerization of HCN referred to by Sauron, which would be favored by moderate pressure, because of Avogadro's law it would be
more likely to be implosive, unless it is a very exothermic reaction occurring under adiabatic conditions. The eventual solid product would probably
be [-CH=N-CH=N-CH=N-]n. Because of the alternating double and single bonds which can exchange places by resonance, it would be electrically conducting
and light-absorbing, probably black in color like graphite, very much like polyacetylene, having anisotropic (due to the -C-N- chain lengths)
mechanical and electrical properties.
[Edited on 7-10-07 by JohnWW]
garage chemist - 6-10-2007 at 17:44
Propane is bullshit... that would give propionitrile if any reaction occurs. For HCN, methane has to be used. Also, the reaction is highly
endothermic, and 600°C is way too low a temperature.
You need like electrically heated platinum wire gauze- expensive as hell. Leave this process to big industry. There are so much better ways to
cyanides in the lab.
12AX7 - 6-10-2007 at 18:24
Or, erm, 1,3,5-triazobenzene? I don't recall offhand how that's named...you know what I mean...
Hmm, that would need an extra H to work...
Tim
Sauron - 6-10-2007 at 19:55
HCN explosively pooymerizes to cyanuric acid.
JohnWW, if you are skeptical about such polymerization, why not get a ouija board and ask the spirits of the workers killed at the Monsanto plant in
Louisiana a few decades ago, how and why they died?
Cyanogen chloride explosively polymerizes to cyanuric chholide in similar fashion.
Cyanogen bromide to cyanuric bromide, ditto. If you read the preparative literature on these you will see that the chemist is warned that they can
explode in this fashion.
@GC you are right, propane is bullshit in this context. And your advice is good advice.
not_important - 7-10-2007 at 00:08
um, I can't see HCN leading to C3H3N3O3.
The polymerisation of HCN is catalysed by bases, industrially it is stabilised by H2SO4 and SO2. The polymerisation gives a number of products, the
exact product mix depending on conditions. Here's a summary of one study:
http://nai.nasa.gov/year5/year4.cfm?PageAction=5&Section...
[Edited on 7-10-2007 by not_important]
franklyn - 8-10-2007 at 15:55
http://72.14.205.104/search?q=cache:XjwDZoB7sg0J:ershdb.cons...
.
JohnWW - 8-10-2007 at 18:49
Anyway, you are literally and figuratively dead wrong about HCN (or its derivatives) polymerizing to cyanuric acid (or its derivatives), which is
C3H3O3N3, often supplied as the dihydrate, the trimer of cyanic acid. Oxygen would have to be somehow introduced for this to happen.
If the polymerization of HCN is highly exothermic, other than in a closed vessel it is unlikely to be complete due to dispersal of some of the HCN,
and poisoning rather than the explosion/implosion would have killed those Monsanto plant workers. The results of the different conditions of
polymerization would probably be similar to those of acetylene; the same conditions that favor C6H6 (benzene) would favor the aromatic trimer C3N3H3,
while the conditions that favor polyacetylene (probably greater pressure) would also favor the long-chain polymer I mentioned above.
EDIT: removed off-topic and inflammatory political comment.
[Edited on 10-9-2007 by Polverone]