mackolol - 4-11-2020 at 13:14
Hello everyone. As the technology progresses and regular home-lab amateur chemist has access to quite good stuff, that can be used in some industry,
ion exchange membranes have caught my eye. It seems that it could be dirt cheap source of chlorine and lye, two of which are extremely useful. From
chlorine for exampl, one can make a lot of extremely useful and quite expensive chemicals, which could be then sold, by small homemade company.
But how's it in practice, has anybody used it? I have that in mind, that it may not be as perfect as it seems. Could one produce reasonable quantity
of chlorine in reasonable time with like 12V power supply to synthesise some acyl chloride for example? Is the whole thing worthwhile?
Ubya - 4-11-2020 at 15:18
i tried looking for an ion exchange membrane (Nafion i think) a few years ago, but it wasn't cheap and it was pretty hard to buy just a small piece
and not a 25m roll. Have you found a cheap source?
Chlorine is already pretty easy to make by electrolysis with cheap sacrificial electrodes. I think the harder step is storing it as you probably need
a good flow rate for an experiment, or you could build an electrolizer big enough to produce directly the necessary flowrate of chlorine.
A cheap source of ion exchange membrane would just make the system "cleaner" (keeping all the junk only on one electode).
If the membrane can resist being in contact with dilute sulfuric acid it would be a way to make H2SO4 with electrolysis without using the clay pot
method
mackolol - 5-11-2020 at 10:38
Yes, nafion obviously is pretty costy, but if it would work as supposed in theory, then it would be worth it.
Production of NaOH and Cl2 from just plain NaCl? Damn I doubt that there is any cheaper source.
I have tried making my own HCl chlorine generator, from tight sealed jar (this one with clamp), took it to glacier, to drill 3 holes in the cap, and
into these holes, I have put 2 electrodes and in the middle, glass L pipe for the gasses to be discharged. I sealed all the thing with putty, but it's
not the best choice in terms of total tightness.
After all the thing wasn't able to produce enough chlorine, probably to the fact that I used acid resistant steel as cathode, which reacted with the
chlorine.
The only good thing for such anode would be probably platinum or MMO, both very expensive, or at least some Cr rich steel, but it's pretty hard to
get, at least here.
Mateo_swe - 6-11-2020 at 15:52
Not all anion or cation exchange membranes are very expensive.
Fumatech has some membranes at 20 Euros for a 20x30cm piece and they have a online shop.
Look under downloads for specifications like thickness, pH range, etc. for different membranes.
https://www.fumatech.com/EN/Download/index.html
Fuelcellstore also has membranes but they are more expensive i think.
It would be more fun and interesting if one can make a DIY membrane that works good.