Lipase-catalyzed synthesis of propyl-phenyl acetate: a kinetic and thermodynamic study.

This study focuses on the synthesis of propyl-phenyl acetate via esterification reaction in the presence of immobilized Candida antartica lipase-B (CAL-B). In this work, the effect of relevant factors (kinetics and thermodynamic) on total percent conversion and process optimization was studied. The reaction was performed in heptane medium with 1:2 molar ratio of benzoic acid: n-propanol with 0.6% (w/v) biocatalyst loading at 40 °C to attain a maximum conversion of 96.1% within 40 min of reaction time. Effect of increase in temperature on ∆G values indicates that lipase is more promising at moderate temperature (40 °C). A second-order kinetic model was proposed to evaluate apparent kinetic constants that indicate a good agreement between the experimental and theoretical data (0.94 ≤ R ≤ 0.99) with high initial reaction rate (113.5 mM/min). Finally, the catalyst CAL-B was successfully reused eight times without any significant decrease in relative activity.