Kinetics of Enzymatic Synthesis of Cinnamyl Butyrate by Immobilized Lipase

This work illustrates the enzymatic synthesis of cinnamyl butyrate by esterification of butyric acid and cinnamyl alcohol. Experiments were performed to study the various operating parameters such as molar ratio, enzyme concentration, temperature, and speed of agitation. Also, the suitable kinetic model for esterification reaction was predicted and the various kinetic parameters were determined. It has been observed that the experimental results agree well with the simulated results obtained by following the ping-pong bi-bi mechanism with dead-end inhibition by both the substrate acid and alcohol. The highest 90% conversion of butyric acid was observed after 12 h at the following reaction conditions: substrate molar ratio 1:2 (butyric acid/cinnamyl alcohol), temperature 50 °C, enzyme loading 2% (with respect to the weight of the substrates), and agitation speed 250 rpm. Diffusional mass transfer limitations between substrate and enzyme surface do not show significant effect on reaction kinetics. Enzyme reusability study reveals that it retains 85% of its catalytic activity after five consecutive cycles.