Development and application of a solid-liquid fluidized bed reactor for the enzymecatalyzed reaction of immobilized glucose isomerase

Isomerization of glucose to fructose with immobilized glucose isomerase yields HFCS with 42 wt% fructose, 50 wt% glucose and 8 wt% other saccharides. For a commercially available biocatalyst, the main parameters governing the behaviour of a solid-liquid fluidized bed reactors are discussed and a reaction model is proposed. Equilibrium data were utilized in the determination of reversible reaction kinetics, performed in continuous stirred reactors at varying process conditions. Mass transfer in the porous biocatalyst was established by a model analogous to heterogeneous catalysis. The axial dispersed plug flow model with closed boundaries was chosen for reactor modelling. Experiments concerning hydrodynamics, overall conversion and conversion profile as function of reaction height were performed. For further experiments a static-mixer was used to reduce the expansion ratio of the fluidized bed. The results indicate that conversions for fixed and fluidized bed reactors are comparable. Ca lculated and experimentally determined values for the axial dispersed plug flow model were in agreement. (ILV)