MeshPL
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Aparatus for sulphuric and hydrochloric acid production
Hello everybody!
Making Sulphuric or hydrochloric acid isn't easy and requires either extraction from drain cleaners or something like that or using not so cheap
chemicals like sodium bisulfate or copper sulfate.
However I had an idea for a somewhat complicated aparatus for making both of theese acids relatively cheaply:
a) NaCl is electrolysed to produce Cl2 and NaOH:
2NaCl + 2H2O--> 2NaOH + Cl2
The only problem is that something like Castner–Kellner apparatus would need to be used and mercury would be required for its operation. I wonder if
mercury could be substituted with melted gallium.
b) Pyrite or sulphur (or any other sulphide) is roasted in air to make SO2:
4FeS2 + 11O2 --> 8SO2 + 2Fe2O3
S + O2 --> SO2
c) activated charcoal catalyst is employed to produce sulphuryl chloriode:
SO2 + Cl2 --> SO2Cl2
d) sulphuryl chloride is hydrolysed:
SO2Cl2 + 2H2O --> 2HCL + H2SO4
Because of presence of sulphuric acid, hydrogen chloride cannot dissolve and bubbles out of the solution. Then, it is collected and dissolved in
another reactor chamber.
Alternatively SO2 and Cl2 could be dissolved directly in water:
SO2 + H2O --> H2SO3
Cl2 + H2O --> HOCl + HCl
HOCl + H2SO3 --> HCl + H2SO4
Are theese reactions at least doable? Could they be employed for domestical HCl and H2SO4 production?
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byko3y
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I can see a problem of purification of at least HCl.
To obtain SO2 you need to burn sulfur, it's relatively difficult of roast an ore.
Also, if you can catalytically convert SO2 and Cl2 to sulfuryl chloride - why can't you just use vanadium catalyst to convert SO2 into SO3?
And you need chlorine generator, which is also a challenge, because the easiest way to obtain chlorine is from HCL and MnO2/KMnO4/TCCA/NaOCl/Ca(OCl)2,
and you can't use this way because you want to produce HCl. You cannot use mercury cell if you plain to live a little more, but you can use some low
performance diphragm cell, or buy a cationic exchange membrane and make a high performance one, though you need some skills to build this equipment.
This is why I ask you once again: why can't you just do a contact process SO3?
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MeshPL
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Well, I could. But, for theoretical considerations, we can assume:
a) I want both HCl and H2SO4
b) I'm just having an idea that may not necessarily work, but it may be worth asking, if it could.
You may be right- purifying HCl may be a problem, but H2SO4 shouldn't. Asuming no strange azeotrope form, we should be able to distill out 98% H2SO4
and becaus of very high acidity no HCl or SO2 will be dissolved in it. With some distillation we sould also be able to get 20% HCl.
I'm still wondering if molten gallium could be used in electrolytical cell for chlorine production. Nevertheless, a membrane would be a better idea,
than mercury.
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j_sum1
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There have been numerous discussions of H2SO4 and HCl synthesis on these boards. A large number of methods have been proposed and used. I don't
think I have seen this one before.
It seems unnecessarily complex. I doubt you would save any money over the other common methods. Sure your raw materials may be dirt cheap but the
equipment you would need to construct, the time you would invest and the probable low yield and unforeseen issues would undoubtedly drive the costs
up.
You could look at the lead chamber process for sulfuric. There is a lengthy thread on it that is worth a read.
I make my sulfuric acid from copper sulfate which is available fairly cheaply from pottery supply places. Admittedly it is time-consuming and it
takes a bit of work to get anything like a reasonable volume. But it is not overly difficult or expensive.
Sodium bisulfate is an acceptable substitute in many situations and really is inexpensive from a pool chemical supplier.
Likewise, there are several methods for HCl: including electrolysis. I think that HCl is easier than H2SO4. But for me, I can buy muriatic acid from
a hardware store pretty easily and the quality is good. If I need to purify it, there are methods -- even without fancy glassware. Pyrolysis of PVC
will get you there and I know that there are members who do this. Again check out the threads.
Your proposed methods may be feasible but I doubt there is much to be gained by pursuing them if cheap acids are your goal. Have a read around.
Acid availability is a common problem and extensively discussed.
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MeshPL
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I know this method is somewhat complex. But I just thought it would be interesting, employing chlorine to oxidise SO2 and SO2 to reduce chlorine.
Although, there are definitly better ways of producing those acids for sure.
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j_sum1
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If the goal is to explore a method rather than to obtain a product, then go for it. It seems interesting.
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byko3y
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You can't use gallium instead of mercury, because gallium doesn't have the overpotential needed to reduce sodium.
There are some more interesting methods of SO2 oxidation, but all of them suck in fact:
- oxidation by electrolsys with membrane US Pat. 4,059,496;
- SO2 autoxidation in aqueous MnSo4 solutions containing H2SO4
- direct oxidation of SO2 in water or some other solvent with a free chorine.
And if you want to prepare sulfuryl chloride - I would be glad to make it too, this thing is really usefull and relatively non-toxic (LC50 900ppm in
4h or rats).
Attachment: The rate equation for SO2 autoxidation in aqueous MnSo4 solutions containing H2SO4.pdf (446kB)
This file has been downloaded 871 times
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MeshPL
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Well, these are rather theoretical considerations, but in the future I might give it a try.
SO2Cl2 synthesis is catalyzed by activated charcoal very well, I remember the reaction was described as "instant".
Yeah, those methods are not very good. Except SO2 + Cl2 in water, what is a pretty simillar thing to SO2Cl2 method.
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420MLGnOhEADsCOPEpro
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Quote: Originally posted by MeshPL  |
Alternatively SO2 and Cl2 could be dissolved directly in water:
SO2 + H2O --> H2SO3
Cl2 + H2O --> HOCl + HCl
HOCl + H2SO3 --> HCl + H2SO4
Are theese reactions at least doable? Could they be employed for domestical HCl and H2SO4 production? |
i just did that reaction
the details are in this thread
http://www.sciencemadness.org/talk/viewthread.php?tid=61267
33rd post
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GrayGhost
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| Quote: Originally posted by MeshPL | Hello everybody!
Making Sulphuric or hydrochloric acid isn't easy and requires either extraction from drain cleaners or something like that or using not so cheap
chemicals like sodium bisulfate or copper sulfate.
However I had an idea for a somewhat complicated aparatus for making both of theese acids relatively cheaply:
a) NaCl is electrolysed to produce Cl2 and NaOH:
2NaCl + 2H2O--> 2NaOH + Cl2
The only problem is that something like Castner–Kellner apparatus would need to be used and mercury would be required for its operation. I wonder if
mercury could be substituted with melted gallium.
b) Pyrite or sulphur (or any other sulphide) is roasted in air to make SO2:
4FeS2 + 11O2 --> 8SO2 + 2Fe2O3
S + O2 --> SO2
c) activated charcoal catalyst is employed to produce sulphuryl chloriode:
SO2 + Cl2 --> SO2Cl2
d) sulphuryl chloride is hydrolysed:
SO2Cl2 + 2H2O --> 2HCL + H2SO4
Because of presence of sulphuric acid, hydrogen chloride cannot dissolve and bubbles out of the solution. Then, it is collected and dissolved in
another reactor chamber.
Alternatively SO2 and Cl2 could be dissolved directly in water:
SO2 + H2O --> H2SO3
Cl2 + H2O --> HOCl + HCl
Are theese reactions at least doable? Could they be employed for domestical HCl and H2SO4 production? |
Electrolysis ClNa with mercury, need catalisator to move sodium to water.
Whith diaphragma is difficultouly ( I make) pot flower porous, because the ion trend neutralizate.
The best is membrane of Naflon but is expensive.
HOCl + H2SO3 --> HCl + H2SO4
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Texium
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Thread Moved
22-11-2023 at 19:25 |
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