Integrated CO Oxidation and SCR for Synergistic Removal of NOx and CO with Energy-Saving and Low Carbon Emissions

Developing synergistic technologies for coremoval of NOx and CO while reducing carbon emissions is a critical challenge in sintering processes, where conventional flue gas treatment systems rely on energy-intensive blast furnace gas (BFG) heating. This study investigates a novel strategy that harnesses the exothermic heat of catalytic CO oxidation to drive downstream NOx reduction. A multiphysics computational fluid dynamics (CFD) model was developed to evaluate the effects of CO oxidation section length ratio, gas hourly space velocity (GHSV), and flue gas parameters on system performance. Results show that configuring the CO oxidation section to one-third of the reactor length achieves optimal synergy, with NO and CO conversions of 95.70 and 62.92%, respectively. Moderately reducing GHSV helps increase the reaction zone temperature, thereby enhancing NO conversion and improving overall system performance. Increases in inlet temperature and CO concentration significantly promote the CO oxidation and its associated heat release, which in turn elevates the system temperature and enhances SCR reaction activity. The proposed configuration maintains NO conversion above 90% across a wide operating range, indicating strong adaptability. Compared to the traditional BFG combustion, the CO oxidation-assisted system reduces annual operating costs and carbon emissions by 78.94 and 99.88%, respectively. This approach offers a cost-effective and low-carbon alternative for industrial flue gas treatment.