Mechanical Stability of the Support

Abstract

Industrial applications of immobilized biocatalysts have been gaining importance in the last decades. Some examples are given in the Chapter 21, Chapter 22 and Chapter 23. If these biocatalysts are used in reactors, such as aerated stirred tank reactors or air-driven reactors, the particles are continuously subjected to hydrodynamic shear stresses, motion and bursting of gas bubbles, and collisions against other particles and reactor parts. Severe abrasion of biocatalyst particles have been observed in these systems (Gjaltema et al., 1995, Hunik & Tramper, 1991). The effect of different kinds of mechanical stresses in reactors largely depends on the properties of the particle itself. Not only on the size, shape and density of the particle, but also ist roughness, hardness, elasticity, effect of fatigue and degree of homogeneity. These last properties determine how a biocatalyst particle is able to accommodate the stresses to which it is subjected in a reactor.