The partial oxidation of a COG (coke oven gas) in a blast furnace is examined in this work using thermodynamic analysis. LTIR and HTIR (Low-temperature and high-temperature indirect reduction) of iron oxides in a blast furnace are also studied. The influences of the reaction temperature, M/H (methane-to-hematite) ratio, and O/F (oxygen-to-fuel) ratio on CH4 conversion and iron oxide reduction are examined. Within the investigated ranges of the parameters, a higher reaction temperature is conducive to CH4 conversion, while at least 97.64% of Fe2O3 is reduced. In LTIR, Fe3O4 is the prime product, with a high level of solid carbon formation. The entire LTIR reaction is characterized by exothermic behavior, so that no additional heat is required to trigger COG partial oxidation and IR. In HTIR, increasing the reaction temperature facilitates CO-based IR and suppresses H2-based IR. A higher temperature produces more Fe, so as to enhance the iron oxide reduction reactions; meanwhile, the FeO reduction is governed by H2 and CH4. When the reaction temperature is higher than 800 °C and the M/H ratio is lower than unity, a heat supply is required to drive HTIR. The O/F ratio in LTIR and HTIR should be controlled below 2 to retard carbon formation and drive iron oxide reduction.
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Building and Construction
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering