Equilibrium Moisture and Thermodynamic Properties on DesorptionProcess of Jatropha Seeds

摘要

The equilibrium moisture content of Jatropha oilseeds was determined by the static method for different conditions of temperature and relative humidity. A diversity of mathematical models were fitted to the experimental data. The model that best fitted the data was used to calculate the thermodynamic properties enthalpy and entropy change, integral isosteric heat and the Gibbs free energy change in the desorption process. These properties were used to discuss the theory application of enthalpy-entropy compensation. The modified Henderson's model was considered adequate to represent and estimate the equilibrium moisture in the desorption process of Jatropha oilseeds. Equilibrium moisture content of Jatropha oilseeds is directly proportional to the relative humidity. Enthalpy and entropy changes were found to be positive, indicating that the desorption of Jatropha oilseeds is an endothermic and irreversible process. A negative change of free energy was obtained, indicating the spontaneous nature of the desorption process in Jatropha oilseeds for conditions evaluated.