Pore-scale numerical study of intrinsic permeability for fluid flow through asymmetric ceramic microfiltration membranes

The asymmetric ceramic microfiltration (MF) membrane is widely used in water treatment processes, yet the dependence of its intrinsic permeability on the microstructure parameters of different layers are not thoroughly understood. In this study, a numerical model combining the Discrete Element Method (DEM) with Lattice Boltzmann Method (LBM) is developed to simulate the fluid flow through the detailed pore structure of an asymmetric ceramic MF membrane. The model is validated by comparing the simulated pure water permeability to experimental data with an average deviation of 8% (Max∼25%). The simulation results show that the pore size D₅₀ and porosity ε, of the top and intermediate layers are dominant microstructure parameters that determine the membrane pure water permeability. A new asymmetric ceramic MF membrane intrinsic permeability K_m as a function of D₅₀, ε and layer thickness h of both top and intermediate layers is derived. The verification of this K_m correlation is conducted by comparison with experimental data and Carman-Kozeny (C–K), Hagen-Poiseuille (H–P) correlations, indicating the proposed K_m correlation can accurately predict the membrane permeability. It provides a useful tool for a fundamental understanding of the effect of membrane microstructures on intrinsic permeability.