Modelling of immobilized Candida rugosa lipase catalysed esterification process in batch reactor equipped with temperature and water activity control system

Abstract

The present work reports on the first principle modeling for the esterification of citronellol and lauric acid using immobilized Candida rugosa lipase in a batch reactor equipped with a temperature and water activity control system. The first principle model for this process was constructed by deriving mass and energy balances equations. Experiments were conducted to determine the kinetic parameters for the esterification of citronellyl laurate and the results were validated using the experimental data. An ordered bi–bi kinetic model was developed by taking into account the inhibition effects of lauric acid as well as the effect of temperature. Moreover, an additional kinetic constant due to the presence of water as a by-product in the reaction system was also verified. Based on the first principle model developed, the parameters of the esterification reaction kinetics were determined using non-linear regression analysis in the MATLAB software. The kinetic model was validated by comparing the profiles between the simulated and the experimental studies in different operating conditions of the reaction. Subsequently, the validated kinetic model was implemented in the first principle model, and simulation studies were conducted using the MATLAB® software. Based on the profiles of acid conversion, reactor temperature and water activity, these models can capture the reaction behaviour with the R2 values of 95.72 %, 84.75 % and 97.67 %, respectively.