The Effect of Sintering Flue Gas Composition on NO Reduction in Coke

ABSTRACT The strategy of substituting combustion air with sintering flue gas in circulating fluidized bed (CFB) systems provides a low‐cost and highly efficient approach for the purification of sintering off‐gas. In this work, coke was employed as the reducing agent, and a high‐temperature vertical tube furnace was used to simulate the dense‐phase region of a CFB to examine the reduction of NO by coke over the temperature range of 750°C–950°C. Research findings indicate that as the temperature increases, the NO reduction efficiency by coke rises significantly from 0.8% to 44.5%. With a gradual increase in NO feed concentration, the NO conversion rate at 950°C progressively decreases to 41.1%. The addition of CO enhances NO conversion, with higher CO feed concentrations leading to greater NO conversion rates. At 950°C, as the CO 2 concentration increases, the NO conversion rate gradually declines from approximately 42% to 30%, suggesting that CO 2 inhibits the NO reduction reaction by coke. This study systematically analyzes the reaction characteristics of NO with coke within the typical oxygen concentration range of sintering flue gas, providing an experimental basis for the co‐processing of sintering flue gas in CFB.