Efficiency of Semi-Automatic Control Ethanol Distillation Using a Vacuum-Tube Parabolic Solar Collector

Abstract

Thailand is an agricultural country with several agro-industrial by-products that can be processed into fuels. Although producing ethanol from agro-industrial by-products is an interesting option, the process of distilling ethanol from fermented agricultural products requires a high temperature to increase the ethanol concentration from 10% to 95%. In this research, solar ethanol distillation equipment incorporating a solar parabolic collector with a vacuum heat absorber tube to increase efficiency by reducing heat loss was designed and developed. An electronic device was used to control the distillation process, maintain the required temperature, and make suitable adjustments to the solar radiation acceptance angles of the parabolic solar collector. Ethanol dilution at concentrations of 10%, 15%, and 20%, and Sato (Thai Rice Wine) were used as the reactant in the distillation process. The result of distilling ethanol distillation with a semi-automatic control using a vacuum-tube parabolic solar collector showed that the thermal efficiency of the receiver was 12.61%, 13.93%, 18.58%, and 17.40%, respectively. The thermal efficiency of the heat exchanger was 11.27%, 10.76%, 13.35%, and 12.35%, respectively. The final concentration of ethanol was 67%, 76%, 82%, and 80%, respectively, and the amount of the distilled ethanol was 330 mL, 352 mL, 398 mL, and 360 mL, respectively.