Chemical looping is one of the promising strategies for carbon capture. In the chemical looping oxygen uncoupling (CLOU) process, the oxygen necessary for the combustion process is released from a metal oxide, called the oxygen carrier, eliminating the direct contact between air and fuel, causing carbon dioxide to be easily separated. The objective of the proposed work is to investigate the interaction of nitrogen and sulfur species with the oxygen carrier material employing various experimental techniques as well as molecular modeling. This research will create an impact on the chemical looping plants that will be built in the future, in the sense that it will provide a fundamental understanding of the pollutant formation during the CLOU process. This understanding would aid in the design of emission control technologies, if a treatment of the carbon dioxide stream is required prior to sequestration depending on the emission levels and regulations. Experimental data that will be produced from this project will provide insight into the effect of such pollutants on the activity of the oxygen carrier, which would help the design of future oxygen carrier materials that would last for many oxidation reduction cycles, thus reducing the cost of the materials.
There has been a great effort in the discovery of oxygen carrier materials that are suitable for chemical looping applications; however, there is a lack of a fundamental understanding of the heterogeneous chemistry occurring on the oxygen carrier surface, especially for the interactions with impurities. In the proposed work, various combinations of copper and manganese-based oxygen carrier and support materials will be tested under CLOU conditions while being exposed to nitrogen and sulfur species to shed light into the heterogeneous reactions taking place on the oxygen carrier surface. The oxygen carrier surfaces will also be simulated using density functional theory and the reaction pathways will be determined. By employing bench-scale experiments and theoretical simulations, this project will provide a fundamental understanding of NOx (nitrogen oxides) and SOx (sulfur oxides) formation mechanisms specific to the CLOU process.
