Mass transfer in infrared drying of jatropha seeds (Jatropha curcas L.)

Abstract

Nowdays, special attention has been directed for Jatropha curcas L. aiming the biodioesel production, since their seeds have a high oil content. Thus, the purpose of this work was to study the drying kinetics of jatropha seeds (Jatropha curcas L.) using infrared radiation (IR) as drying method. The temperatures of the IR radiation source used in the experiments were 70, 80 and 90°C. The IR drying behavior of jatropha seeds was characterized by the presence of only one falling rate period, thus showing that internal resistances related to seed structure control the mass transfer. The diffusion model adequately described the process, with mean relative deviations lower than 14%. Neglecting shrinkage of the seeds during IR drying led to an overestimation of the mass transfer by diffusion. The temperature dependence of effective mass diffusivity was described using an Arrhenius relationship.