Extractive distillation employing a dissolved salt as separating agent

A process of extractive distillation, employing a dissolved salt rather than a liquid solvent as separating agent, was studied on a pilot plant scale. Aqueous ethanol was fractionated in a 12‐tray, bubble cap column with potassium acetate present in the liquid phase. Even relatively small concentrations of salt eliminated the azeotrope. An overhead product completely free of separating agent was obtained directly from the column. A technique is described for metering salt at a steady rate, and for achieving rapid solution of the salt in the reflux stream.