Sciencemadness Discussion Board

interesting membrane free chloralkali cell

macckone - 22-6-2021 at 11:53

https://www.nature.com/articles/s41467-018-02877-x.pdf

Basically it is a sodium manganese oxide composite.
This seems good for an amateur lab but not for a production environment yet.

no expensive membranes or mercury required.
manganese oxides are readily available.
The initial powder step uses sodium carbonate and high temperatures.
The second step in electrode formation uses acetylene black, carbon nanotubes and PTFE powder. The carbon nanotubes can probably be substituted for graphitized nylon fiber which just requires heating fishing line to high temperature in an oxygen free environment. PTFE tape can be powdered with enough persistence. If anyone knows of a good source of carbon nanotubes, let me know.

khlor - 21-8-2021 at 22:59

That's very interesting, however witohut a separation I'm still worried about chlorine gass yields, true, there won't be hypochlorites formation due to the Manganese Oxide destroying. but the chlorine formed in the anodes will still dissolve in the basic electrolyte and thus reduce the yield of the chlorine and NaOH production per watt. The presented paper doesn't go into much lengh at explaining how much of the chlorine is lost becoming ClO- but I guess it could still be used to get a fairly simple and slightly less efficient chloralkali process at home without worrying the sodium hydroxide to be contaminated with sodium hypochloride.

metalresearcher - 22-8-2021 at 11:05

I read this article, but is industry still really using Hg cathodes and asbestos membranes ? I thought that is banned. So this is a great idea.

macckone - 22-8-2021 at 15:45

metalresearcher,
most Hg plants have been closed, and very few are using diagphram cells anymore.
cation exchange membranes are more efficient and don't have the environmental factors.
The benefits of this type of cell is that it is more efficient than even the cation exchange membranes at a theoretical level.
Making it practical is another matter.