Modeling Enzymatic Cascade Reactions Immobilized in Plug-Flow Reactors for Flow Biocatalysis

Flow biocatalysis has emerged as a promising technology for the sustainable production of chemicals. Multiple immobilized enzymes are often used as biocatalysts to perform enzymatic cascade reactions in flow biocatalytic systems. When designing packed-bed reactors with multiple immobilized enzymes, the enzymes are distributed in porous particles, and the porous particles are distributed in catalyst zones. A recently developed methodology is extended for selecting spatial immobilization distributions in batch reactors to packed-bed reactors. Mechanistic models are used to compare the three most basic designs for a packed-bed reactor, i.e., mixed individually immobilized enzymes, separated individually immobilized enzymes, and mixed co-immobilized enzymes. For first-order microkinetics, the design with co-immobilized enzymes was found to always outperform the other two. Separating individually immobilized enzymes in two zones was proven to outperform mixing them in one zone for any positive order reaction kinetic.