1093, 1273 KにおけるH₂-CO混合ガスによるFe_1-yO焼結ペレットの還元反応の速度解析

抄録

In order to achieve carbon neutrality, CO₂ emission from ironmaking processes must be decreased. Blast furnace operation with an injection of hydrogen gas and capturing CO₂ from the exhaust gas is one of the promising technologies to reduce CO₂ emission from the ironmaking process. When hydrogen gas is enriched in a blast furnace, reduction of iron oxide with both H₂ and CO gas occur. Because reduction of iron oxide with H2 is endothermic, the gaseous reduction rate of solid iron oxide must be improved. Therefore, it is necessary to understand the reduction rate of iron oxide with an H₂-CO gas mixture in a wide H₂/CO ratio range. In this work, simulated iron oxide pellet was reduced with H₂-CO gas mixture at 1093 and 1273 K, and the kinetic analysis was performed using an unreacted core shrinking model assuming H₂-CO gas mixture as a single component of the reducing agent. The obtained apparent rate constants were linearly increased with the hydrogen content of reducing gas. Furthermore, the apparent rate constants were increased with hydrogen content at 1273 K much more than at 1093 K, which would be caused by the increasing driving force of hydrogen reduction at a higher temperature.