Characterization of an enzymatic packed-bed microreactor: Experiments and modeling

A micro packed-bed reactor (mu PBR) based on two-parallel-plates configuration with immobilized Candida antarctica lipase B in the form of porous particles (Novozym (R) 435) was theoretically and experimentally characterized. A residence time distribution (RTD) within mu PBRs comprising various random distributions of particles placed in one layer was computationally predicted by a mesoscopic lattice Boltzmann (LB) method. Numerical simulations were compared with measurements of RTD, obtained by stimulus-response experiment with a pulse input using glucose as a tracer, monitored by an electrochemical glucose oxidase microbiosensor integrated with the reactor. The model was validated by a good agreement between the experimental data and predictions of LB model at different conditions. The developed mu PBR was scaled-up in length and width comprising either a single or two layers of Novozym (R) 435 particles and compared regarding the selected enzyme-catalyzed transesterification. A linear increase in the productivity with the increase in all dimensions of the mu PBR between two-plates demonstrated very efficient and simple approach for the capacity rise. Further characterization of mu PBRs of various sizes using the piezoresistive pressure sensor revealed very low pressure drops as compared to their conventional counterparts and thereby great applicability for production systems based on numbering-up approach.