RogueRose - 29-11-2015 at 22:30
I'm trying to figure out what would be the best (cost vs performance) to use for the Chlor-alkali production cell membrane. I have looked over
different ways to produce these two bases and it seems that this method fits the bill best as I can make both KOH and NaOH with the same setup (maybe
2 separate membranes..?)
The goal of this cell is to be able to produce 1lb of KOH/NaOH a day with little to no supervision (fill cells, set timer, temp monitors, etc).
Ideally I would be able to fill the cell with 7-14 days worth of brine and allow it to run until completion. I always get confused here as to whether
I should build a larger cell to produce a weeks worth in say 8-24 hours or build the size that runs continuously for 7-14 days.
I looked over the slacked lime method of making NaOH and I'm not sure I can get the purity I would like from this method, so I think the electrolysis
is what I have to go with.
For those who know about this process, I have seen people say that graphite anode/cathode's can be used and I have seen that Titanium/Nickle are
recommended as well. Which is best or what are the drawbacks of one of these?
Finally the membrane is what I am most concerned about. I have seen people say they have used gypsum board (drywall??) as well as things like
asbestos and Nafion (PTFE coated something or other) which I have read is the "best" but I'm not sure I can procure this at a reasonable price. It
would be REALLY great if I could use this cell (maybe replace membrane and cath/anode's as per need) for other applications as I saw some other
interesting compounds being discussed.
byko3y - 30-11-2015 at 00:31
Industrial chloralkali production devices, that use membranes and transitional metals electrodes and walls, can work indefinitely, provided the NaCl
solution is pure.
Chlor-alkali really attracts my attention, but in the end - you can buy a dirt cheap pure NaOH that was made using the devices I've mentioned. The
real product that is demanded is in fact chlorine, it's hard to transport, it's much cheaper to produce in place. Chlorine is used for desinfection
because it's safer for health, much safer for health then bromine.
If you can't utilize the chlorine - why would you bother with chlor-alkali cell?