Immobilized laccase reactors for process intensification: Kinetic comparison of batch and continuous-flow systems

Immobilized enzyme reactors operated under flow conditions are promising for process intensification in biocatalytic transformations; however, systematic kinetic comparisons between batch and flow configurations remain limited. Using acetosyringone-mediated malachite green (MG) decolorization as a model reaction, the kinetic behavior of an immobilized laccase system was compared between batch and flow modes. Laccase immobilized on an amino-polyethylene glycol-dimethylacrylamide copolymer resin was applied in batch and packed-tube flow reactors, and MG decolorization was monitored spectrophotometrically. The reaction behavior was analyzed using a pseudo-first-order kinetic model, and rate constants and activation energies were determined for laccase solution, immobilized laccase in batch, and immobilized laccase in flow systems. The packed-bed flow reactor exhibited higher reaction rates, achieving approximately 70% MG decolorization within 6.28 min compared with about 78% conversion after 60 min in batch operation. Arrhenius analysis revealed a higher apparent activation energy in the flow system, indicating stronger temperature dependence under continuous operation. The immobilized enzyme was reused in repeated batch and flow runs without noticeable performance loss. Overall, these results demonstrate process intensification under continuous-flow operation and provide a quantitative kinetic framework for comparing batch and flow immobilized enzyme systems.