Supercritical Extraction of Valeriana Officinalis L. Roots. Mathematical Modeling and Experiments
Sustainable process-product development & green chemistry
SCF as Solvent Substitutes (T1-8P)
Keywords: Mathematical modeling; Supercritical Fluid Extraction; Valeriana Officinalis L.; Mass transfer model
Supercritical extraction of natural material is used regularly to obtain valuable substances especially by food and pharmaceutical industries. A mathematical model for the extraction of essential oil from valerian (Valeriana Officinalis L.) roots using supercritical carbon dioxide (SC-CO2) as a solvent was investigated in this study. Extracts from the roots of valerian have long been used in alternative medicine for the treatment of insomnia and are the most well recognized herbal sedatives worldwide.
The model is based on Mass transfer balance for solid and supercritical fluid phases. Experimental data to test the model were obtained at pressures of 150-300 bar, particle diameter of 2.5-4.2 10-4 m and solvent flow rates of 4-16 10-7 m3/min at constant temperature of 310 K, void fraction of 0.1 (v/v) in bed and static time of 20 min. Furthermore, the model is able to explain the effects of solid void fraction, bed length and extraction time on yield of extraction. Investigation of the solid-solvent interaction using the linear, Brunauer-Emmett-Teller (BET) and Langmuir adsorption isotherm for the supercritical fluid extraction (SCFE) were also discussed. Effective diffusivity (Deff), axial dispersion coefficient (DL) and film mass transfer coefficient (ki) are the model parameters.
A very good agreement between experimental data and model results was obtained.
Presented Monday 17, 13:30 to 15:00, in session SCF as Solvent Substitutes (T1-8P).
