(135f) Correlation of the Physical and Solid State Chemistry Changes for a CuO-Fe2O3-Al2O3 Oxygen Carrier during Reduction with H2 and CO for Chemical Looping Combustion Applications
AIChE Annual Meeting
Monday, October 30, 2017 - 2:17pm to 2:39pm
The changes in physical and chemical properties during reduction and oxidation for the Cu(Fe2âxAlx)O4Â OC are unique and not thoroughly understood. The act of transferring oxygen to the fuel source induces the formation oxygen vacancies causing the structure to distort and ultimately change phase when enough oxygen has been depleted. The phase change to base metal and metal oxide components due to the stripping of lattice oxygen is often referred to as the reduction route, and comparably the oxidation route being the reverse process. With this noted, chemical properties can vary from solid-state solution changes including predominant phase, the reduction and oxidation routes, and component migration that can occur due to lattice distortion and reorientation. In addition, physical properties of the material can also be impacted including particle size changes during redox reactions, density changes associated with predominant phase, surface area, etc. This comprehensive study identifies and correlates these property changes with extent of solid oxygen carrier conversion for the development and implementation of accurate reduction and oxidation models for further use in process scale up and optimization strategies. A combination of various characterization techniques including in-situ X-ray diffraction, Scanning Electron Microscopy, Thermogravimetric analysis coupled with mass spectrometry and others are used to establish correlations between the property changes with the metal oxide during reduction with CO/H2 and oxidation with O2.