Hydrogen production from steam reforming of coke oven gas and its utility for indirect reduction of iron oxides in blast furnace

Abstract

Hydrogen and synthesis gas (syngas) can be produced from steam reforming (SR) of coke oven gas (COG). When the reforming gas is used for indirect reduction (IR) of iron oxides in blast furnaces (BFs), carbon dioxide emissions can be lessened. Motivated from utilizing hydrogen and mitigating greenhouse gas emissions in ironmaking, the reaction phenomena of SR of COG are investigated thermodynamically. Low-temperature and high-temperature IR of iron oxides using reforming gas as a feedstock is also analyzed. With appropriate operating conditions, the maximum H2 and syngas yields are 3.5 and 4.2 mol (mol fuel)−1, respectively. Two different reforming gases are employed to reduce iron oxides. When the reforming gas/hematite (R/H) molar ratio is no less than 1, Fe2O3 conversion is always higher than 98.5%, whether low-temperature or high-temperature IR is carried out. This reveals that COG possesses the potential as a reducing agent in BFs. The reactions of IR from the two reforming gases are almost identical, implying that the operation of SR from COG for producing hydrogen or syngas and reducing iron oxides in BFs is flexible.