Distillation of Ethanol in a Solar Still: Studies on Heat and Mass Transfer

Abstract

A single-basin solar still may be used for primary concentration of dilute ethanol produced from fermentation. In order to describe the simultaneous heat and mass transfer in the still, different models have been proposed and tested against some experimental measurements on a still having a 1 m × 1 m basin area. Measurements were based on steady-state operation using electrical heating and unsteady-state operation using solar energy. The proposed models were found to have similar trends even though their derivations were based on different approaches. The models were found to overpredict the mass fluxes of ethanol (Me) and water (Mw) at high basin temperature and ethanol concentration, with different degrees.