Kinetic Modelling of the Drying Behaviour of Palm Kernel (Dura Species)

Abstract

Palm Kernel (PK) obtained from the oil palm fruit during palm oil milling, requires reduced moisture for efficient processing and storage. This study aimed to develop a drying kinetic model for predicting the drying behaviour of KP (Dura Species). The drying patterns of the PK at four temperatures: 40, 50, 60, and 70 °C, were studied using a conventional laboratory oven. The samples’ weight loss and the corresponding moisture ratio were determined under the different temperatures. Five different mathematical models- Lewis, Page, Avhad and Marchetti, Logarithmic, and Henderson and Pabis were fitted to the experimental data and statistical indicators like Coefficient of determination (R²), Root Mean Square Errors (RMSE), and Mean Sum of Squares of Errors (MSSE) were used to determine the most suitable model for the experimental data. The results showed that the rate of moisture evaporation increased at higher temperatures, but this rate slowed down progressively as the moisture content decreased over time. While all models adequately fit the experimental data, the Avhad and Marchetti model emerged as the most suitable for predicting PK drying kinetics. This model consistently matched the experimental data across all temperatures (40, 50, 60, and 70 °C), with R² values ranging from 0.9787 to 0.9944, RMSE values from 0.0406 to 0.0383, and MSSE from 0.0016 to 0.0014 across the different temperatures. Additionally, the palm kernel drying process was found to exhibit a low activation energy value (32.59 kJ/mol), indicating an energy-efficient drying process.