Water vapor effects on attrition and elemental migration of iron-based oxygen carrier in chemical looping combustion

Chemical looping combustion (CLC) offers a novel approach to simultaneous power generation and carbon capture. However, the commercial viability of CLC depends on durable and cost-effective oxygen carriers (OCs). This study assesses the impact of water vapor (WV) on the attrition of red mud OC, crucial for industrial CLC deployment. Findings indicate a significant reduction in the average attrition rate, from 0.06%/h to 0.03%/h, attributed to the limitation of Fe₂O₃ reduction, resulting in reduced volumetric and temperature changes in the presence of WV. A developed volume-based model reveals attrition contributions in the order of chemical > mechanical >> thermal stresses, influencing OC particle surface morphology. Remarkably, the formation of the iron-oxide layer remains unaffected by WV, reducing agents (CO or H₂), or superficial velocities, suggesting scalable iron recovery from attrition with enhanced flexibility in future applications.