Georg L. Schwebel

Use of natural ores and waste materials as oxygen carriers for chemical-looping combustion

The increasing CO2 levels in the atmosphere require an immediate action in order to avoid irreversible climate changes. Chemical-looping combustion (CLC) is an innovative technology that provides an energy and cost-effective separation of CO2 for further capture and storage and thereby helps to mitigate the anthropogenic CO2 emissions from thermochemical fuel conversion. The solid oxygen carrier is a core component of every CLC system and the choice of the oxygen carrier depends on the fuel and operation conditions. Low-cost oxygen carriers tend to be more suitable for the process as the lifetime of the oxygen carrier material is often limited by side reactions with fuel ash, or by carryover losses in the ash separation. A series of natural ores and waste products have been investigated as potential oxygen cares, such as Mn-ore, Fe-ore, ilmenite. The materials are chosen based on their content of oxides that have proven to have promising oxygen transporting capabilities. The results lead to summary of criterion for further screening of the existing materials for more reactive and better suited candidates for the process.