Abstract: Promoting the use of biomass fuels and hydrogen in rotary-kiln pelletizing is an effective pathway to low-carbon and cleaner pellet production. A custom-built combustion test platform was employed to compare flame characteristics, flue gas composition, and heating performance for biochar (BC) versus pulverized coal (PC), for hydrogen versus natural gas/coke oven gas, and for the co-combustion of BC with these hydrogen-containing gases (HCGs). It was found that compared with PC, BC produced a more concentrated flame and a higher peak flame temperature, attributed to its porous microstructure and catalytically active ash; its lower nitrogen and sulfur contents also yielded reduced NO_x and SO₂. Under equal thermal input and oxidant conditions, higher hydrogen content in HCG enlarged flame size, improved temperature uniformity, and enhanced heating efficiency to the furnace, but NO_x emissions increased. In BC-HCG co-combustion, higher hydrogen fractions in HCG strengthened coupled reactions and further improved heating efficiency. Although NO_x from BC-hydrogen exceeded that from BC-natural gas, it was similar to BC-coke oven gas and remained lower than that from BC alone, due to biochar gasification. These results provide some theoretical guidance for the application of biomass and hydrogen in ferrous metallurgy.