CINÉTICA DE SECAGEM E PROPRIEDADES TERMODINÂMICAS DOS GRÃOS DE SOJA

Abstract

Soybean (Glycine max), belonging to the Fabaceae family, is one of the most important crops for large-scale grain production and agribusiness. In this way, one should be concerned about the quality of the grains stored. Drying is a pre-stage of grain processing in order to preserve and quality during storage. The objective of this work was to evaluate the drying kinetics of soybean grains and to determine their thermodynamic properties. The soybean samples were collected at the Goian Federal Institute - Ceres Campus, having a moisture content of approximately 0.21 decimal on a dry basis (b.s). The samples were dried at temperatures of 20, 30, 40 and 50 °C using a BOD up to the hygroscopic equilibrium range. The coefficient of determination (R²), mean relative error (P), estimated mean error (SE), chi-square (χ²) and behavioral distribution were used for the adjustment of drying data. of waste. Through the selected mathematical model and the Arrhenius equation, we obtained the effective diffusion coefficient and the activation energy. The dryings started with RX close to 0.82 and finished with hygroscopic equilibrium. The average drying time was 9 hours and 30 minutes. It was concluded that the mathematical model that best fit the kinetic drying of soybean grains was that of Midilli; the increase of the drying air temperature increases the increase in free energy of Gibbs, while the enthalpy values reduce and the entropy maintained its negative values.