Diffusional behaviour of immobilised glucose oxidase

Glucose oxidase immobilised on Amberlite CG‐50 by glutaraldehyde technique, was used to study the behaviour of immobilised enzyme reactor with respect to diffusional restrictions. The film diffusion effects were observed by assaying the performance of column reactors of different diameters, 1.0, 1.5 and 2.0 cm and each packed with two catalyst weights of 1.0 and 1.5 g to give different bed depths. The columns were packed with bulk catalyst preparation of approximately 118 μm average size and the substrate feed rate through them was varied from 5 to 50 ml min−1. The conversions increased for the same values of space times with factors that increase the linear velocity of feed and thus decrease the film thickness. Internal pore diffusional resistances could be satisfactorily described by Thiele analysis. The diffusional restriction was minimum when the largest effectiveness factor of 0.94 was obtained with the particles in the size range of 56–65 μm, the value of pseudo reaction rate constant (K') in this range was 34.7 cm3 g−1 cat.min−1. The results of the analysis of the experimental work achieved a good fit to the predicted curve well.