Turkish Journal of ChemistryKinetics and Thermodynamics of Oil Extraction from Sun ower Seeds in the Presence of Aqueous Acidic
Department of Chemistry, Faculty of Sciences and Letters,
Trakya University, 22030 Edirne-TURKEY
Department of Food Engineering, Faculty of Agriculture,
Trakya University, Tekirdağ-TURKEY
Abstract: Oil extraction was performed in aqueous HCl, H2SO4 and H3PO4 solutions with n-hexane (C6H14) at 30, 40, 50 and 60 oC using 10 gr of sunflower seeds over 1 h with 10-min. sampling intervals. The optimum acid concentration was wt. 10% for each acid, and the highest oil yield was obtained in the extraction procedure with n-hexane containing H2SO4. The extraction process was observed with regard to the percent oil yield versus time, and the reaction order was found to be first-order kinetics by the differential method. The activation energy for the oil extraction kinetics of sunflower seeds with 10% H2SO4 was found to be Ea=4.2 kJmol-1, and the activation thermodynamic parameters at 60 oC were DH \neq =1.43 kJmol-1, DS \neq=-309.3 Jmol-1K-1 and DG \neq =104.4 kJmol-1. The enthalpy value was DH=11.2 kJmol-1, and the other thermodynamic parameters at 60 oC were DS=36.75 Jmol-1K-1 and DG= -1.07 kJ mol-1.
Key Words: Hexane, kinetics, oil extraction, sulfuric acid, sunflower seed, thermodynamics.
Turk. J. Chem., 24, (2000), 247-254.
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Other articles published in the same issue: Turk. J. Chem.,vol.24,iss.3.