Modelling of water transport through mixed‐ion conducting dense ceramics

Abstract

This study develops and demonstrates a model that characterizes defect transports, responsible for water transport within dense ceramics, and calculates the diffusion coefficients for those defects. The multi‐species mass transfer processes within yttrium doped barium cerates are modelled by applying the Nernst‐Planck equation to the system. The Nernst‐Planck equation with suitable boundary conditions is adopted to compute defect diffusion coefficients in COMSOL Multiphysics. All related equations, based on charge and defect conservation, are solved numerically and validated experimentally. The model also predicts the concentration distribution of the defects and potential profiles throughout the membranes. The results provided convenient insights about the water transport and charge distribution as a function of membrane thickness.

Modeling of steam permeation through the high temperature proton‐Conducting ceramic membranes

“…This shortcoming can be avoided or reduced by optimizing the operating conditions to run the SOFC. The phenomenon of such spontaneous potential was previously reported by Al et al When one side of BCY20 membrane was exposed in wet N 2 atmosphere, the electrical potential change was immediately detected. Understanding the mechanism of the spontaneous potential formation can help to design high temperature steam detector…”

“…To predict and optimize the operation parameters of ceramic membranes, there are several studies on the modeling of proton conduction in ceramic membranes. Selgin et al built the model of the steam permeation process with Nernst–Planck equations to regress the diffusion coefficients of proton and oxygen vacancy. Because of the hypothesis of electric neutrality of Nernst–Planck, the model cannot get the solutions on the surface charge of BCY membranes.…”

“…In this article, a transient mathematical model has been established to describe the steam permeation through the HTPCM perovskite membranes, in which the distribution of the charged defects in the membranes is taken into consideration. The transfer of charged species in the solid electrolyte is described by the PNP equations . The effects of a variety of parameters including the membrane thickness, operating temperature, and steam partial pressures on the steam permeation process have been simulated and carefully discussed.…”