KINETIC MODEL FOR FAME PRODUCTION USING IMMOBILIZED LIPASES IN A SOLVENT-FREE SYSTEM

A kinetic model was developed to describe FAME production from refined, bleached and deodorized palm oil (RBDPO) in a solvent-free system, using Thermomyces lanuginosus lipase, in free and immobilized form. The limitations of substrate mass transfer, enzymatic inhibition and discontinuous feeding of alcohol were considered. The kinetic model for the enzyme in free and immobilized form was validated experimentally, under the same process conditions (34 degrees C, 0.145mg protein/g oil, 4.10:1 methanol: oil molar ratio). The kinetic model predicted a FAME content of 73.47 wt % at 9 hours, with a relative error of 0.140% using the enzyme in free form, while the FAME content predicted by the kinetic model was 47.04 wt % at 9 hours with a relative error of 0.026 using the enzyme in immobilized form. The decrease in the percentage of esters using the enzyme in immobilized form was attributed to limitations by external mass transfer.