Modeling of H₂ Permeation through Electroless Pore-Plated Composite Pd Membranes Using Computational Fluid Dynamics

This work focused on the computational fluid dynamics (CFD) modeling of H₂/N₂ separation in a membrane permeator module containing a supported dense Pd-based membrane that was prepared using electroless pore-plating (ELP-PP). An easy-to-implement model was developed based on a source-sink pair formulation of the species transport and continuity equations. The model also included the Darcy-Forcheimer formulation for modeling the porous stainless steel (PSS) membrane support and Sieverts' law for computing the H₂ permeation flow through the dense palladium film. Two different reactor configurations were studied, which involved varying the hydrogen flow permeation direction (in-out or out-in). A wide range of experimental data was simulated by considering the impact of the operating conditions on the H₂ separation, such as the feed pressure and the H₂ concentration in the inlet stream. Simulations of the membrane permeator device showed an excellent agreement between the predicted and experimental data (measured as permeate and retentate flows and H₂ separation). Molar fraction profiles inside the permeator device for both configurations showed that concentration polarization near the membrane surface was not a limit for the hydrogen permeation but could be useful information for membrane reactor design, as it showed the optimal length of the reactor.