Mass transfer limitations in diffusion-limited isotropic hollow fiber bioreactors

Diffusional mass transfer limitations in hollow fiber bioreactors - with de nsely packed whole cells in its extracapillary space to perform biotransfor mation reactions - have been studied theoretically using a steady-state dif fusion and reaction model. Simple analytical expressions have been derived to calculate the radial and axial concentration profiles for zero- and firs t-order kinetics, as well as to plot effectiveness factor versus Thiele mod ulus plots for first-order kinetics. The influence of the magnitude of the effective diffusion coefficients, the thickness of the isotropic membrane a s well as the size of the annular cell region have been assessed to optimis e the reactor performance.