quantumcorespacealchemyst
Banned Shitposter
Posts: 213
Registered: 17-10-2014
Member Is Offline
Mood: No Mood
|
|
Carbon disulfide by electrolysis
I am wondering if using a graphite (pure, glassblowing rod) as a positive electrode, close to a negative electrode of either carbon or tantalum foil,
in molten sulfur, will produce CS2. The temperature in theory, only being enough to melt Sulfur. The electrodes must not arc.
I have been unable to find information about this here.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
There's definitely one problem with that: molten sulphur isn't an electrolyte, so conducts electricity very poorly.
C and S<sub>8</sub> do not combine to CS<sub>2</sub> easily. A high temperature process for its synthesis along those lines
seems to have been largely abandoned in favour of a reaction between methane and sulphur.
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Blogfast you've said it well. Although passing sulfur vapor though a spark gap using graphite electrodes might get you a little bit of your target
molecule.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by BromicAcid  | | Although passing sulfur vapor though a spark gap using graphite electrodes might get you a little bit of your target molecule. |
Sounds like a fun way! 
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Per Atomistry on CS2, which is an extract from the historical literature ( http://sulphur.atomistry.com/carbon_disulphide.html ):
"Carbon disulphide is prepared by passing sulphur vapour over red hot charcoal. The preparation may be carried out on a small scale by heating pieces
of charcoal in a combustion tube placed in a furnace slightly tilted, a Liebig potash bulb, immersed in ice, being attached to the lower end of the
tube, and small pieces of sulphur introduced into the upper end of the tube which is then closed with a cork. Sulphur vapour passes over the red-hot
charcoal and impure carbon disulphide containing sulphur in solution is gradually formed and collects in the cooled receiver. ....
Manufacture of Carbon Disulphide
Manufacture of Carbon Disulphide by the action of sulphur. The reversible reaction
C + 2S ⇔ CS2
has been studied at 800° to 1100° C. by Koref. It has been suggested that the formation of carbon disulphide is preceded by that of a solid
sulphur-carbon complex, just as the oxidation of carbon is believed to be preceded by the formation of a complex CxOy.
For the manufacture of carbon disulphide on the large scale, the charcoal is contained in a large vertical cast-iron cylinder, ten to twelve feet high
and from one to two feet in diameter. This cylinder is surrounded by brickwork and heated by a fire beneath. The sulphur is introduced through a
hopper connected with a side tube at the base of the cylinder. The carbon disulphide vapour is led away from the top of the cylinder through a pipe,
the end of which dips under water, where most of the product condenses. Beyond the water condenser is a series of tubes in which condensation is
completed. Hydrogen sulphide, one of the impurities, escapes condensation and passes on, being subsequently absorbed in slaked lime.
Instead of an iron cylinder furnace, retorts made of refractory material are sometimes employed. The water condensers may be of the open tank type, a
layer of about six inches of water on top of the disulphide affording a thoroughly efficient seal. The liquid may be purified from dissolved sulphur
by steam distillation. A modern method for the final rectification of the carbon disulphide consists in the continuous distillation of the crude
liquid in two similar fractionating columns fitted with reflux condensers. The first column is maintained at a temperature just above the
melting-point of sulphur and fed with crude carbon disulphide from above, whilst the second is kept at a temperature slightly above the boiling-point
of pure carbon disulphide and fed at the top with the purified liquid from the first column. Condensation of the vapours leaving the lower end of the
second column yields pure carbon disulphide. The waste gases (hydrogen sulphide, etc.) escape from the reflux condensers and are condensed by further
cooling, any carbon disulphide obtained being passed back to the first column. The sulphur which separates is drawn off as liquid from the still of
the first column.
Furnace of Carbon Disulphide
Electric Furnace for the Production of Carbon Disulphide. A thermo-electrical process for the production of carbon disulphide from its elements is
also largely employed, especially in America. The type of furnace generally employed is shown diagrammatically in fig. The heat emanated from the
electrodes E1 and E2 melts and ultimately vaporises the sulphur, which then passes up through the tower of charcoal. The furnace is self-regulating in
that if it becomes too hot, the sulphur, melting at a more rapid rate than it volatilises, rises up over the electrodes, thus reducing or cutting off
the current. Two-phase alternating current is employed, and the efficiency exceeds 40 per cent.
The sulphur may be evaporated and superheated either in the reaction chamber itself or in an attached chamber before it is brought into contact with
the charcoal.
Carbon disulphide may also be formed by the action of sulphur dioxide on carbon....
When sulphur is heated with acetylene at temperatures up to 650° C. and the products condensed, a brown oil is obtained which contains 77 to 83 per
cent, of carbon disulphide, with some thiophen and thiophten. The optimum temperature for producing the latter compounds is 500° C.
When calcium carbide and sulphur are heated together at 270° C. carbon disulphide in about 20 per cent, yield and considerable quantities of carbon
are produced. At higher temperatures the amount of carbon disulphide diminishes, only traces being detected at 500° C."
[Edited on 22-2-2015 by AJKOER]
|
|
|
j_sum1
Administrator
Posts: 6232
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
That actually sounds vaguely do-able for the home chemist. You would want to have all your safety contingencies thought through properly and do it
where any escaping H2S is unlikely to bother anyone, but in principle, quite simple.
|
|
|
Molecular Manipulations
Hazard to Others
Posts: 447
Registered: 17-12-2014
Location: The Garden of Eden
Member Is Offline
Mood: High on forbidden fruit
|
|
I'm not sure, but I'm nearly certain that will take very high temperatures, like over 1000 K. Passing hot sulfur dioxide over even hotter carbon is
how this would happen, if at all. The reaction even at those temperatures is probably endothermic, which means it occurs by the removal of the
products (carbon disulfide and carbon monoxide), and that keeps it from not reaching equilibrium acc. Le Chatelier's principle. Thus you'll need a lot
more sulfur dioxide then the calculated amout in order to react with all the carbon.
Keeping the very volatile carbon disulfide from burning afterwards will be a trick.
-The manipulator
We are all here on earth to help others; what on earth the others are here for I don't know. -W. H. Auden
|
|
|
Molecular Manipulations
Hazard to Others
Posts: 447
Registered: 17-12-2014
Location: The Garden of Eden
Member Is Offline
Mood: High on forbidden fruit
|
|
| Quote: |
I am further interested in processing the CO. This is not the immediate issue. Funny enough, reacting it to Methane and reacting it with Sulfur to
make more CS2 may be possible.
|
I bet you are.
Reacting what with methane? Carbon monoxide? To make what? Why not focus on surviving high school without poisoning yourself with carbon monoxide or
burning your parents house down. Then you can think about chemistry.
-The manipulator
We are all here on earth to help others; what on earth the others are here for I don't know. -W. H. Auden
|
|
|
Nicodem
|
Thread Moved
22-2-2015 at 12:32 |
Nicodem
|
Threads Merged
22-2-2015 at 12:33 |
Bert
|
Thread Pruned
22-2-2015 at 13:36 |
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Per Wikipedia on CS2 ( http://en.m.wikipedia.org/wiki/CS2 ), as previously noted by Blogfast:
"As lower temperature reaction, requiring only 600 °C utilizes natural gas as the carbon source in the presence of silica gel or alumina
catalysts:[6]
2 CH4 + S8 → 2 CS2 + 4 H2S
The reaction is analogous to the combustion of methane."
So, for those comtemplating alternate seemingly simpler routes, note the possible need for a catalyst. Also, per my post comments, temperature ranges
can greatly alter yield.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
