Geometric and Reynolds number effects on oregano (Lippia berlandieri Schauer) essential oil extraction

Effects of geometry and Reynolds number on the production of essential oil were investigated. Experiments, performed on an oregano packed bed, were de signed to reproduce expected plant operating conditions. A diffusive model was found to apply to oil extraction and effective diffusion coefficients w ere calculated as a function of the bed L/D ratio and Reynolds number. Effe ctive diffusivities were found to be of the same order of magnitude as thos e for drying of similar materials (congruent to 10(-9) m(2)/s). Statistical analysis showed that RE effects are more important, but that extraction is also affected by LID variations. Application of this information to select the optimum operation parameters needs additional plant-specific, cost-rel ated data. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.