Originally Posted by
dtknowles
I am not sure you can dissolve the salts out of charcoal, I think they are trapped in the carbon crystals, but I might be wrong.
You are correct that to get solid potassium hydroxide you would have to do as you described or use some other method but if you dissolve potassium carbonate in water it creates potassium hydroxide.
"potassium carbonate when dissolved in water, becomes potassium hydroxide and carbon dioxide."
K2CO3 + H2O -> 2KOH + CO2
Wood ash lye is an alkali metal hydroxide mostly potassium hydroxide KOH. It can be obtained by using rainwater to leach wood ashes, which are strongly alkaline and highly soluble in water.
If this is not correct, then my internet research is in error.
Tim