Numerical simulation of the effect of hydrogen injection and oxygen enrichment interaction on PCI in a blast furnace

• Hydrogen injection can reduce CO2 emissions by up to 16.6% when partially replacing pulverized coal injection, but it also decreases coal burnout. • Co-injection of hydrogen and PCI increases wall temperatures near the raceway and tuyere outlet, necessitating enhanced cooling to prolong blast furnace service life. • Increasing oxygen enrichment by 3% compensates for hydrogen-induced temperature drops, raising burnout by 4.2% and average raceway temperature by 43 K. • Optimization of pulverized coal particle size distribution can further improve burnout during hydrogen co-injection.