V. Middelkoop

Interlaced X-ray diffraction computed tomography

A new data-collection strategy for Xray diffraction computed tomography experiments is presented that allows, post experiment, a choice between temporal and spatial resolution.

Mixed Conducting Ceramic Capillary Membranes for Catalytic Membrane Reactors: Performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Capillaries

Oxygen-permeable perovskite ceramics with mixed ionic-electronic conducting properties can play an important role in the high temperature separation of oxygen from air. Such membranes are envisaged for application in catalytic membranes reactors and in oxy-fuel and pre-combustion technologies for fossil fuel power plants enabling CO2 capture. Since large-scale gas separation applications demand high membrane surface/volume ratios, membranes with capillary or hollow fiber geometry have a distinct advantage over tubular and flat sheet membranes. The fabrication and performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) capillary membranes is presented. The capillaries were made by a spinning technique based on phase inversion using a sulfur or non-sulfur containing polymer binder. Attention is given to the polymer solution and ceramic spinning suspension in order to avoid the formation of macrovoids and achieve gastight membranes. The comparison of the performance of sulfur-free and sulfur-containing BSCF capillaries with similar dimensions revealed a profound impact of the sulfur contamination on both the oxygen flux and the activation energy of the overall oxygen transport mechanism. In addition the effect of activation layers on oxygen permeation is studied.