Thanks for all the information!
It will be a while before I can begin work, or even if it starts. While I would be working on the control module, someone else is in charge of the rest. He might just spend $150 on premade stuff, or scrap the idea altogether.
As far as scale, we would be using a normal sized water heater for the tank, with one of the elements removed (leaving only the bottom one). The fluids would be pumped from the bottom to the top, and methanol would be added through a venturi
in this pump assembly. Evaporated methanol would flow up through another pipe into a condenser and collection tank.
I would be monitoring the temperature of the main fluid media, such that it doesn't get high enough for it to evaporate. Yet, at the same time, I will be reading the temperature of the vapors in an attempt to keep it in a window allowing the methanol to boil out.
Should be fun! I hope I get to take a stab at it. If it doesn't work, he can always go get the premade stuff instead, so we are only out time and supplies.