Mathematical modelling, kinetics and energy consumption for Drying Aloe Vera gel in hot Air dryer with exhaust Air recycle

The research aimed at mathematical modeling, kinetics and energy consumption of a hot air dryer with air recycle (0, 50%, and 75%). A hot-air dryer capable of recycling the exhaust air was used. The experimental data were fitted to standard thin-layer drying models in MATLAB 2007. The best model was selected according to the coefficient of correlation (R2), chi-square (c2) and root mean squares error (RMSE). These indices showed that the Midilli et al. model has the best fit for explaining the experimental data. The required energy was minimum at 0.5 m/s and 60˚C for 0%, 50% and 75% recycled air levels and was maximum at 1.5 m/s and 40˚C for all recycling levels. The hot-air recirculating system also reduced energy requirements and increased the drying time for aloe vera.