Title: Evaluation of the Rectification Efficiency of Pot-Stills by Means of Number of Theoretical Plates
Abstract: In order to evaluate the rectification efficiency of pot-stills, we investigated the number of theoretical plates of ethanol in the distillation of ethanol solutions. The ethanol solution was charged in a pot-still and distilled by pouring the distillate into the liquid in the pot-still. After the distillation was continued for 2 h, a small amount of liquid in the pot-still and the distillate were taken as samples for analysis. The number of theoretical plates was measured at definite experimental conditions of the atmospheric temperature, the distillation rate, the ethanol concentration in the pot-still, and the figure of the pot-still. When the figure of pot-still was defined, the slower the distillation rate, the bigger was the number of theoretical plates. However, the distillation was unstable at lower distillation rates. Stable distillation at a lower rate was carried out by reflux from a condenser setup on the top of the pot-still. Because the number of theoretical plates was affected by partial condensation of the vapor in the pot-still, the number of theoretical plates was controlled by the volume of the liquid from the partial condenser.