Kinetics and thermodynamics of oil extraction from sunflower seeds in the presence of aqueous acidic hexane solutions

Kinetics and thermodynamics of oil extraction from sunflower seeds in the presence of aqueous acidic hexane solutions

Oil extraction was performed in aqueous HCl, H2SO4 and H3PO4 solutions with n-hexane (C6H14) at 30, 40, 50 and 60° C using 10 gr of sunflower seeds over l 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 $E_a=4.2 kJmol^{-1}$, and the activation thermodynamic parameters at 60°C were $Delta H^{neq}=1.43 kJmol^{-1}$,$Delta S^{neq}5^ =-309.3 Jmol^{-1}$ and $Delta G^{neq}=104.4 kJmol^{-1}$. The enthalpy value was $Delta H=11.2 kJmol^{-1}$, and the other thermodynamic parameters at 60°C were $Delta S=36.75 Jmol^{-1}K^{-1}$ and $Delta G=-1.07 kJmol^{-1}$

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Turkish Journal of Chemistry-Cover
  • ISSN: 1300-0527
  • Yayın Aralığı: Yılda 6 Sayı
  • Yayıncı: TÜBİTAK