CFD modeling and simulation of concentration polarization in microfiltration of oil-water emulsions; Application of an Eulerian multiphase model

In this study, a 2D CFD modeling and simulation of concentration polarization (CP) phenomenon in microfiltration of oil-water emulsion in a narrow rectangular membrane module was presented. As the novelty of this research, an Eulerian based multiphase method was investigated for the first time to capture the concentration of emulsified oil droplets in different extents of membrane module. It was shown that this new model is highly compatible with concentration polarization theory and is highly capable for determining CP profile and mass boundary layer behavior in different operating conditions, as well. In this research it was proved that under developed feed cross-flow shows better performance in terms of membrane surface cleaning. Also it was shown that a small portion of oil droplets accumulates at the roof of membrane module feed channel due to gravity. The simulation results proved that for under developed feed cross-flows, lower feed Reynolds number induces a lower CP profile peak despite increasing the oil droplet concentration on membrane surface and at the feed channel roof.