Chemical looping combustion (CLC) is a cutting-edge approach that enables power generation and carbon capture to occur simultaneously. For CLC technology to be commercially viable, it's essential to have oxygen carriers (OCs) that are not only durable and reactive but also cost-effective. This is because the degradation or sintering of OCs can reduce the efficiency of the process and lead to higher costs. Despite extensive research on common materials like iron, nickel, and copper-based OCs, there has been a lack of focus on improving both the durability and reactivity of OCs, particularly concerning the risk of element migration during degradation.
At the University of Kentucky, researchers are developing iron-based OCs, utilizing red mud from the plentiful waste of bauxite, to implement affordable chemical looping methods. In the CLC process using iron-based OCs, iron transitions between oxidation states within the reactor, which may cause degradation and potential iron migration, impacting the particles' surface structure, porosity, and strength.
The process of making use of the fine particles resulting from OC degradation in CLC has not been thoroughly explored. Present findings indicate that it's feasible to separate and concentrate iron from these fines, achieving an iron concentration as high as 89% Fe2O3 from bauxite waste fines that originally contained 43% Fe2O3. This method turns the by-products of CLC attrition into a valuable commodity. Additional details will be presented at the upcoming conference.
 

Iron-based oxygen carrier,Chemical looping combustion,Attrition,Iron enrichment,Bauxite waste