Notes on Sodium Hydroxide Production + Purification
Contents
Basics
- So unlike the production of potassium hydroxide, which is quite simple, sodium hydroxide it a bit more complicated. First of ash is not the feedstock used, but instead saltwater and electricity. This is done in the Open Source Brine Electrolysis Apperatus. The electrolysis is simple (outside of the obtaining of membranes and electrodes). The problem is the purification of the sodium hydroxide. It emerges from the cell in the form of a aqueous solution with typical concentrations 10-12% (w/w) sodium hydroxide and 15% (w/w) sodium chloride (as stated in this source). Since they are roughly similar compounds they are difficult to separate.
This leaves me imaging two ways we can go with this
- We use it in it's impure (sodium chloride contaminated) state (This may be fine for many reactions that are unaffected by the presence of the sodium)
- We Seperate it out
If we choose option one the liquid is evaporated to concentrate the solution, or a powder is made and the work is done
If we choose option two I list the following as possible separation methods in order of complexity
- Seed Crystals and Multiple Recrystallizations (Low energy + cost; May not work well enough)
- Dissolution Temperature in Various Solvents (I didn't find enough info on this yet)
- Melt Temperature (Works well, Does use a lot energy)
Closing Note/Calling all Chemists+Chemical Engineers
I Eric am in no way a chemical engineer. I had 2 years of basic chemistry in High School, and read around a bit, but I will need someone more experienced to help out with all this chemical production craziness (especially once designing chemical reactors and software to run them, and just checking the equations I bring up). So feel free to add in here
