RESISTANCE OF BIOCATALYST FIXED-BEDS UNDERGOING PARTICLE DESTRUCTION

The hydrodynamic resistance in a biocatalyst particle fixed bed reacto r was studied. The biocatalyst used was immobilized glucose isomerase supported by an organic carrier composed of cross-linked proteins. The bed structural deterioration caused by compression-enhanced particle fragmentation and washing-out was considered. The resistance functions (friction factor vs. Re) for four different cases of polydisperse mat erial with increasing spread of the size distribution, corresponding t o different extents of particle destruction, were evaluated. The exper iments were repeated with three different values of the bed compressio n, corresponding to different sample positions in the large-scale isom erization column. The relationships obtained exhibited slopes slightly greater than those predicted theoretically for stable packings. This effect can be explained by the increased irregularity of voids due to bed degradation, accompanied by the formation of hollow spaces and sud den changes in the cross-section of the channels. A semiempirical corr elation recommended by Reichelt was found to represent the experimenta l data well for the practically important region of Re > 0.5.