Mass transport in hydrogen permeation through Pd-based membranes

This chapter aims at providing an overall overview on the different approaches to modeling the hydrogen mass transport through Pd-based membranes, paying particular attention to the kinetic and transport phenomena occurring in nonideal conditions, which can be caused by several and, most of the times, concurrent occurrences, like sufficiently high hydrogen concentration, appreciable influence of adsorption and desorption, the presence of significant mass transfer resistance in the external gas phases and in the porous support, and the unwanted effect of inhibition phenomena due to the presence of certain species in mixture like CO and CO₂. The motivation lies in the fact that a more precise membrane characterization including these phenomena is crucial in operating conditions close to those of interest for industrial applications.