Dynamic Modeling and Pilot-Scale Design of a Chemical Looping Combustion Reactor Using Red Mud as an Industrial Waste Oxygen Carrier

The use of industrial wastes as oxygen carriers (OCs) in chemical looping combustion (CLC) has gained recent attention as these materials demonstrate the potential to be a cost-effective alternative to synthetic OCs. A key limitation in the development of CLC with industrial waste OCs is the lack of modeling efforts for CLC systems with these materials. This work presents a dynamic multiscale packed-bed reactor CLC model of the oxidation and reduction stages to investigate the performance of red mud, an industrial waste from the alumina refining industry, as an OC. Kinetics describing the oxidation reaction of red mud with oxygen and the reduction reactions of red mud with CH4, CO, and H2 fuels were fitted and assessed using lab-scale experimental data. To further advance CLC with red mud, the packed-bed model is used to design a pilot-scale CLC system, following scaling constraints and design heuristics. The proposed pilot-scale design exhibits moderate utilization of the red mud OC, an average of 89% fuel conversion during the dynamic reduction stage, and is estimated to produce a total thermal energy output of 235.6 kWh. Evaluation of the red mud performance under various reactor conditions at pilot scale provides valuable insights into the potential for this industrial waste to advance CLC toward industrial relevance and adoption.