Catalytic reforming of model tar compounds from hot coke oven gas with low steam/carbon ratio over Ni/MgO–Al 2O 3 catalysts

Abstract

The catalytic reforming of toluene and naphthalene was performed to investigate the possibility for directly converting tar components from hot coke oven gas (COG) with lower steam/carbon (S/C) molar ratios to light fuel gases. The NiO/MgO–Al 2O 3 catalysts reduced exhibited excellent catalytic activity, stability and sulphur tolerance. The effects of various reaction conditions and S/C ratios on the catalytic performance were investigated in detail. Toluene and naphthalene were completely converted into small gas molecules at 700–800 °C and S/C = 0.28. An appropriate amount of steam benefited the methanation reaction of CO and H 2. The effects of N 2, CH 4 or CO in COG were also discussed. Relative to N 2, CO contributed to the conversion of toluene and the formation of CH 4, but the opposite was true for CH 4. The sulphur tolerance was tested by adding H 2S in the feed gas. The reaction results were explained by a water cycle mechanism.