Reduction of CO₂ Emission from Off-Gases of Steel Industry by Dry Reforming of Methane

In a novel process, CO₂ and CH₄ from the off-gases of the coke oven and blast furnace are used in homogeneous reforming of those greenhouse gases to valuable syngas, a mixture of H₂ and CO. Synthetic mixtures of the off-gases from those large apparatuses of steel industry are fed to a high-temperature, high-pressure flow reactor at varying temperature, pressure, residence time, and mixing ratio of coke oven gas (COG) to blast furnace gas (BFG). In this study, a maximal reduction of 78.5 % CO₂ and a CH₄ conversion of 95 % could be achieved at 1350 °C, 5.5 bar, and a COG/BFG ratio of 0.6. Significant carbonaceous deposits were formed but did not block the reactor tube in the operational time window allowing cyclic operation of the process. These measurements were based on prior thermodynamic analysis and kinetic predictions using an elementary-step reaction mechanism.