Kinetic study of the esterification of unsaturated free fatty acids Available to Purchase

The kinetics and thermodynamics of the esterification of oleic, linoleic and linolenic acids using a batch reactor are described in this study. The effect of relevant factors on ester conversion, such as reaction temperature, dose of sulfuric acid as a catalyst and methanol/free fatty acids (FFAs) (oleic, linoleic and linolenic acid) mole ratios are studied. The results show that the maximum conversion of oleic and linoleic acids was 88% at 40:1 methanol/FFAs molar ratio, temperature of 68°C, catalyst 2 wt% of FFAs and reaction time of 30 min. A pseudo-homogeneous kinetic model was proposed for the esterification. The effect of temperature on the rate constants is represented by Arrhenius equation, and the activation energy was found to be 13·35, 43·42 and 45·51 kJ/mol for linolenic, linoleic and oleic acids, respectively. The thermodynamic parameters including ΔG, ΔS and ΔH were determined. Thermodynamic studies have revealed that the reaction was a non-spontaneous and endothermic one.