THIN‐LAYER DRYING KINETICS OF SESAME HULLS UNDER FORCED CONVECTION AND OPEN SUN DRYING

Abstract

ABSTRACT Sesame hulls are a useful by‐product of the sesame processing industry. The sesame hulls are produced at a high moisture content (68% wet basis) and need further drying to prevent deterioration. In this study, both open sun drying (OSD) and forced convection drying (FCD) at 42, 55, and 76C and 1.2 m/s air velocity were investigated. Six common thin‐layer drying models were fitted to the experimental data. Several statistical parameters were used to evaluate the performance of thin‐layer drying models, including r2, x2, root mean square error (RMSE) and residuals. Sesame hull drying was found to take place completely in the falling rate region. The modified Page model was found to describe OSD data well, while the Wang and Singh model was the best model for describing FCD. Effective diffusivity was found to be 1.89 × 10‐8 m2/s and 7.36 × 10‐10 to 1.20 × 10‐9 m2/s for OSD and FCD, respectively. Activation energy was also found to be 12.95 kJ/mol for FCD.