Kinetics and mechanism of esterification of isoamyl alcohol with acetic acid by immobilized lipase

Abstract

In this study, the effects of the rate enhancement of isoamyl acetate formation by immobilized <i>Mucor miehei</i> lipase catalysed esterification of isoamyl alcohol with acetic acid were investigated. The esterification reaction was studied in ten different solvents and <i>n</i>-heptane was found to be most suitable. The rate of the reaction was affected by the addition of molecular sieves (3Å) and temperature. The effects of different reaction parameters such as lipase and substrate concentrations were studied. The activity of immobilized lipase was found to be maximum at lipase concentration of 12 mg/mL and at a reaction temperature of 55ºC; retained about one third of its initial activity up to seven reaction cycles after repeated use. The kinetics of the reaction can be described by Ping-Pong Bi-Bi mechanism with acid inhibition. The parameter values were estimated by non-linear regression analysis.