The role of non-ideality in H permeation through membranes

Model development and validation of hydrogen transport through supported palladium membranes

“…3. In general, these too are in good agreement with literature values [35]. However, the thermodynamic factor has been discussed in literature as being ≤1.…”

“…(11) accounts for changes in H activity with H-content and is derived for pure Pd from H 2 solubility data [34]. For the diffusion coefficient parameters, D H,∞ , H 0 sol and E diff , are deduced from literature, with the reference temperature T ref = 250 • C [27,[34][35][36][37].…”

Diffusion of H through Pd membranes: Effects of non-ideality

“…The concentration profile can then be determined from the following equation, which was derived from Eq. (6) and given in [14],…”

“…(1) cannot be employed directly. Recently, a procedure has been given for determining concentration-independent diffusion constants from the concentration-dependent ones for this steady-state situation [14].…”

A Review for Consistent Analysis of Hydrogen Permeability through Dense Metallic Membranes

“…Recently, some studies have proposed methods for analyzing hydrogen permeability consistently. In this paper, three methods are reviewed: (a) pressure-dependent hydrogen permeation coefficient [15,[19][20][21], (b) analysis of hydrogen diffusivity based on thermodynamic factor [22][23][24][25], and (c) consistent description of hydrogen permeability based on hydrogen chemical potential [26]. Four examples of the application of the consistent description of hydrogen permeability are introduced: (a) prediction of hydrogen flux under given conditions, (b) comparability of hydrogen permeability with the hydrogen permeation coefficient for the power law, (c) understanding of the anomalous temperature dependence of hydrogen permeability found recently in Pd-Ag alloy membranes [27], and (d) alloy design of V-based alloy membranes with high hydrogen permeability and strong resistance to hydrogen embrittlement [28].…”