Estimation of effective diffusivity, thermodynamic parameter and drying kinetics exploration in coffee berries drying

This study focuses on green coffee beans (Coffea arabica) drying kinetics in a tray dryer within the range of 50-60 degrees C. The kinetic parameters were estimated using several theoretical, semi-empirical models in which the semi-empirical model was well fitted with the experimental data and the two-parameter model and least error in Logarithmic model with the observation of kinetic parameter (k) increases with temperature. Arrhenius equation was used to find the activation energy (E-a) as 40.413 kJ/mol and the effective diffusivity coefficient also varied from 1.0833 x 10(-9) to 6.1862 x-10(-9) m(2)/s. The surface heat and mass transfer coefficients (h and h(m) (average)) were found to be 14.14 W/m(2) K and 0.0344 m/s. Thermodynamic properties such as enthalpy (Delta H), entropy (Delta S) and Gibbs free energy (Delta G) were 37.5293 kJ/mol, - 0.211 kJ/mol K and 106.931 kJ/mol. The parameters such as specific moisture extraction rate (SMER), moisture extraction rate (MER) and specific energy consumption (SEC) were estimated as 0.001659 kg/kWh, 0.0033195 kg/h and 602.5 kWh/kg and the observed results are higher as compared to other literature. [GRAPHICS] .