Evaluation of extractive contact units for oil extraction from dehulled sunflower seed

The efficiency of an extractive system generally depends on kinetic, thermodynamic and technological parameters. Each of these factors affects the extractive effectiveness, although the overall result depends on their interaction. In the present work this interaction is analyzed for oil extraction from dehulled sunflower seed. Experiments on laboratory scale were made to calculate the kinetic and thermodynamic parameters of the extraction. The behavior of the system in 2 typical contact units (mixer-settler and semicontinuous extractor) was studied and models assuming equilibrium conditions were formulated. The soundness of the models was checked by pilot-plant tests and good agreement was obtained as long as the residual oil concentration in the solid was higher than ca 0.01 c_so At lower oil concentrations the contact time becomes the main factor of the process, and the extraction is much less affected by the extraction ratio and the composition of the liquid.