CITRONELLYL BUTYRATE SYNTHESIS IN NON-CONVENTIONAL MEDIA USING PACKED-BED IMMOBILIZED CANDIDA RUGOSA LIPASE REACTOR

The synthesis of citronellyl butyrate by direct esterification reaction catalyzed by immobilized lipase from Candida rugosa was studied in a continuous packed bed reactor using /7-hexane as organic solvent. Parameters such as residence time, temperature, and pH were examined. The optimum conversion was obtained at a flow rate of 1 ml/min (residence time 8 min), temperature of 50 °C, and pH 7.5. At high temperature, biocatalyst was rapidly deactivated with respect to time. The immobilized lipase was stable at pH range of 6 to 9. The deactivation of biocatalyst was increased at pH of immobilized lipase 4 and 10 in comparison with pH range from 5 to 9. The esterification reaction in packed-bed reactor was modeled by ping pong model and ping pong with product inhibition model. The observed kinetics behaviour of esterification reaction was found to follow a ping pong with product inhibition model. In this study, the conversion of butyric acid and stability of immobilized lipase was higher in the system with molecular-sieve than in the system without molecular-sieve