I've been trying to design a device to increase the percentage of ethanol and water, or to at least concentrate the water-alcohol mixture without using distillation.
The way I'm trying to do this is by using a dry ice bath (dry ice+propanol). I then insert a stainless steel vessel in the bath with the said water-alcohol mixture (between 30-60% ethanol to begin with). Going by the ethanol-water phase diagram and the temperature of the ice bath (-78C), I should, in theory, be able to concentrate the mixture up to ~80% ethanol.
Where this goes wrong is that instead of cleanly separating into water ice and concentrated water-ethanol mixture, what I get is a kind of ice-alcohol slushy.
Any suggestions on how to get a clean separation and get ice that I can scoop out?