Sciencemadness Discussion Board

Does a kiln need to be covered for Electrolysis?

Superficial Red - 27-9-2023 at 12:51

Hello,

I am attempting to do molten electrolysis of lithium carbonate, and I am using a kiln to reach the desired temperature. However, for the experiment to work, the electrolyte needs to be exposed to the air. Does a kiln need to be covered in order to reach the desired temperature? What are the dangers of this? Any input is appreciated.

Rainwater - 27-9-2023 at 13:32

Corrosive molten alkaline salts like to eat their crucible.
Both carbon and alumina.
Youll need to protect the kiln floor from pops amd bumbs with some kiln paper.

At 750, LiCO3 makes a nice low fire glaze for ceramics. But if it foams over, it will react with the refractory and act as a flux, causing the material to melt.

Handle the room temp powder with caution. Lithium salts have psychological effects. Dust is an inhalation hazard

Getting the metal is not easy in quantity. It dissolves in the molton salt. Atleast in my downncell.

Why add air to the reaction? You trying for the oxide or peroxide?

Superficial Red - 27-9-2023 at 13:52

Quote: Originally posted by Rainwater  

Why add air to the reaction? You trying for the oxide or peroxide?


I am using a muntz brass cathode and a nichrome 60 anode to have Lithium carbonate split into carbon on the cathode and oxygen on the anode with lithium oxide being left over. The goal is for the co2 in the air to react with the lithium oxide to form lithium carbonate thereby replenishing the lithium carbonate. Do you know if lithium oxide at 770° C favors reacting with atmospheric CO2 or atmospheric O2?

Rainwater - 27-9-2023 at 14:22

Just done the thermodynamics and the reaction of lithium metal with o2 is preferred over the reaction with CO2, BUT that doesnt mean anything in this setup as both reactions will be spontaneous.
Any co2 converted into lithium carbonate will likely be decomposed by electrolysis back into co2 gas.
Ive never tried this reaction to produce carbon. Would be very cool if it works

Superficial Red - 2-10-2023 at 12:56

Quote: Originally posted by Rainwater  
Just done the thermodynamics and the reaction of lithium metal with o2 is preferred over the reaction with CO2, BUT that doesnt mean anything in this setup as both reactions will be spontaneous.
Any co2 converted into lithium carbonate will likely be decomposed by electrolysis back into co2 gas.
Ive never tried this reaction to produce carbon. Would be very cool if it works


What was the method you used to do the thermodynamics of the reaction?

Rainwater - 2-10-2023 at 16:21

Havent made a good calculator to calculate electrochemical equations yet.

The gibbs free energy math is easy with this
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
But in an electrochemical cell, things are a lot different. Over potentials rein king there.
Along with many other factors.

If your wanting to reduce carbon dioxide, uv light is the go to.
If you can make it work in the lab, there is a Nobel prize in it for you.

[Edited on 3-10-2023 by Rainwater]