A mathematical model for predicting the temperature and mass
transfer rates in a distillation tank was developed and investigated
in this study. The accuracy of the simulation model was examined
by comparing its predictions with experimental results. The findings
are summarized as follows:
1. The hourly distillation rate and daily distillation capacity varied
with the solution temperature and condensation surface
and determined the heat supplied by the solar radiation
collector.
2. The errors in the model predictions of the mass transfer rate,
which were based on the mass transfer equation, were examined.
It was observed that there was 10% difference between the
model and experimental results for Stages 1 and 2 of the
distillation process. The difference was caused by errors in the
circulation temperature in the solar radiation collector, the solution
temperature, and the condensation surface used for the
model simulation. In addition, the concentration in Stage 1 of
the distillation process determined by the model was 30%
higher than that determined by experiment. However, the difference
was reduced to 5% by continuous stirring of the solution
or the use of a solution produced by fermenting cassava. There
was 3% difference between the Stage 2 concentrations determined
by the model and experiment.
3. In the hypothesis of the partial distillation rate of vaporized
ethanol-water, there is no leakage and the ethanol-water is
condensed into liquid, and the entire distilled liquid is released
from the distillation tank. However, in the testing of the system,
the values of the parameters that affected the condensation
efficiency were observed to decrease on the condensation surface
with increasing mass transfer rate, resulting in a decrease in
the condensation rate.
4. The separation of the temperature and concentration or the use
of a heterogeneous mixture could cause differences between the
ethanol distillation capacities and batch concentrations obtained
by the model and experiment