Predicting Intrinsic Permeability of a Double Porosity Cellular Ceramic Using X-ray Micro-tomography

Abstract

The microstructure of a porous cellular ceramic exhibiting two spatial characteristic lengths was characterized to determine parameters of its pore space morphology and connectivity. In order to assess the hierarchical microstructure, X-ray computed micro-tomography was employed as an imaging technique to supply three-dimensional images in two spatial scales. Two samples, at different sintering temperatures, were produced by emulsification of sunflower oil in aqueous aluminum oxide suspensions using gelatin bloom 90 as the gelling agent, dodecyl sodium sulfate as the surfactant and native cassava starch as the gelling and porogenic agent. Image processing and morphological characterization were performed on each spatial scale, individually allowing the calculation of the total porosity and pore size distribution of the ceramic sample. For the numerical simulation of the intrinsic permeability, representative images of the two spatial scales were superposed in a single super-image. This simulation was performed on the 3D pore network extracted from the super-image. The simulated permeability results were interpreted on the basis of the microstructure.