Continuous Esterification using Lipase-Entrapped Amphiphilic Copolymeric Gel Beads

Lipase-entrapped NIPA-co-PEGMEA gels composed of amphiphilic N-isopropylacrylamide (NIPA) and hydrophilic poly(ethylene glycol) methyl ether acrylate (PEGMEA) were previously developed as a means to improve enzymatic activity and stability in organic media. This study focuses on a continuous process for the esterification of oleic acid and ethanol catalyzed by gel beads using the fixed bed method. Monodisperse millimeter-sized gel beads were prepared using a production method combining sedimentation polymerization and two-fluid atomization. The reaction rate was expressed using the ping-pong bi-bi mechanism. A continuous reaction process was successfully demonstrated. The observed values of the conversion of ethanol in the effluent were smaller than the values estimated by a mathematical analysis. This can be attributed to the accumulation of by-product water in gels.