Drying kinetics of Baru almond (<i>Dipteryx alata</i> Vog) used for the production of biodiesel

Abstract

This study aimed to evaluate the drying kinetics of Baru (Dipteryx alata Vog), fit different mathematical models to the experimental values as a function of the water content, determine the diffusion coefficient and energy of Baru almonds during the drying process. Baru almonds were dried at 50, 60 and 70°C temperatures in a tray dryer until the water content reached 13% b.u. A non-linear regression analysis was performed to fit five mathematical models to the drying experimental data. The effective diffusion coefficient was obtained by fitting the mathematical model of the liquid diffusion. The diffusion coefficient variation, based on the drying temperature, was analyzed using the Arrhenius model, which made it possible to determine the activation energy. The drying process of the Baru was best represented by the two-term model. The diffusion coefficient showed values ranging from 18.15 × 10^-11 to 27.62 × 10^-11 m2/s and 15.36 × 10^-11 to 37.08 × 10^-11 m²/s. The ratio between the diffusion coefficient and the drying temperature may be described by the Arrhenius equation, with activation energy of 23.7 and 49.08 kJ/mol and velocities of 1.75 and 2.35 m/s, respectively.

Keywords: Biotechnology, Fick's law, mathematical modeling