Development of a mathematical model and simulation of mass transfer of solar ethanol distillation in modified brewery tank

摘要

The objective of this study was to develop a mathematical model of the mass transfer in a modified brewery tank for producing fuel ethanol. To reduce fossil fuel consumption, 50 flat-plate solar collectors were used as the heat source for the two stages of a distillation process for increasing the ethanol concentration. A 350-L distillation tank with 10%v/v (Stage 1) and a 70-L distillation tank with 40%v/v (Stage 2) were employed in the experiment used to develop the mathematical model of the mass transfer. A difference of approximately 10% was observed between the model predictions and the experimental results of the distillation product of Stage 1, whereas the predicted concentration was approximately 30% higher than that of the experiment, although this was reduced to approximately 5% by homogeneous mixing of the solution. Regarding the distillation process of Stage 2, there was approximately 10% difference between the predicted and experimental products, and approximately 3% difference between the predicted and experimental concentrations. The differences are attributed to errors in the heat transfer rate prediction of the model, which varies directly with the solar radiation values. (C) 2014 Elsevier Ltd. All rights reserved.