There are quite a few threads here relating to ethanol recovery, but not many I could find that related to remediating the inevitable water contamination most ethanol extractors will experience at one point or another with their expensive hydrophilic solvent. So I figured I’d start a thread for those who are looking to reproof their ethanol via reflux distillation to discuss different builds and designs for getting our ethanol proof to that magic 190. As a disclaimer, I’m definitely no expert and know there are quite a few members here who have much more experience in still building than myself. I just figured I’d open the conversation and hopefully get those individuals to join in with their tips and recommendations.
My own current build is not very fast, but it gets the job done. It is a liquid-managed (LM) inline “Bok” design, which means my reflux ratio is controlled by my takeoff rate. This takeoff rate varies greatly depending largely on the surface area of the packing. The surface area of the packing mostly depends on the packing material used (marbles, pot scrubbers, plates, etc.), the diameter of the column, and the height of the column. Other designs which I am not nearly as familiar with are vapor-managed (VM) and coolant-managed (CM) stills. This link sums up their differences nicely.
As I mentioned earlier, the design I am most familiar with and is supposedly easiest to build would be the LM inline Boka. It’s been years since I built it and it definitely needs some upgrades, but I think I only spent around $300 on the entire build. The links I’ll provide below are detailed design plans and operating instructions for such a design.