Catalytic methanation of CO and CO₂ in coke oven gas over Ni-Co/ZrO₂-CeO₂

The methanation of CO and CO₂ present in coke oven gas was performed in a fixed-bed catalytic reactor at a reaction temperature between 200 and 400 C. Different support materials, including SiO₂, Al ₂O₃, ZrO₂, and CeO₂, were doped with a different percentage of active metals using a standard impregnation and coprecipitation method. The catalysts were characterized using Brunauer-Emmett-Teller analysis, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and temperature-programmed desorption techniques. The activity of all samples was tested in terms of the percentage of CO and CO₂ conversion and CH₄ selectivity. The results were analyzed on the basis of the difference in the catalytic performance at different active metal loadings and support materials. The effect of the catalytic support on the reducibility, morphology, and active metal dispersion was investigated. The ZrO₂-CeO₂-supported catalyst prepared under coprecipitation can attain 100% CO conversion at around 300 C and ≥95% CO₂ conversion at 400 C and has a CH₄ selectivity of 99%.