Effect of particle-size distribution and particle porosity changes on mass-transfer kinetics

Effective mass-transfer kinetics depend on particle-size distribution (PSD) and particle porosity (among other complex phenomena). The pore-diffusion flux can vary with adsorbate loading - if the amount of adsorbed species is sufficiently large it can lead to hindrance effects that substantially change particle porosity. By use of batch kinetic adsorption experiments the general rate model was used to investigate the effect of PSD and variation of particle porosity on the pore-diffusivity coefficient, Dp. It was proved that neglec-ting these phenomena can lead to misinterpretation of experimental data. Modelling of HPLC profiles using PSD and conventional modelling with mean diameters was also examined and compared.