Tri-reforming of methane: A novel concept for synthesis of industrially useful synthesis gas with desired H₂/CO ratios using CO₂ in flue gas of power plants without CO₂ separation

A new process concept that has been proposed for effective conversion of CO₂ in the flue gases from electric power plants without CO₂ pre-separation, which can be used for the production of synthesis gas (syngas) with desired H₂/CO ratios for synthesizing clean fuels and chemicals, was presented. The tri-reforming concept represents a new way of thinking both for conversion and utilization of CO₂ in flue gas without CO₂ separation, and for production of industrially useful syngas with desired H₂/CO ratios using flue gas and natural gas. Experimental results with Ni catalysts were described. Catalytic tri-reforming of methane could be achieved successfully with high CH₄ conversion (> 97%) and high CO₂ conversion (> 80%) for producing syngas with desired H₂/CO ratios of 1.5-2 over supported Ni catalysts at 800°-850°C under 1 atm without the problem of carbon formation on the catalyst. Among the catalysts tested for tri-reforming, their ability to enhance the conversion of CO₂ followed the order of Ni/MgO > Ni/MgO/CeZrO > Ni/CeO₂ ≈ Ni/ZrO₂ ≈ Ni/Al₂O₃ (ICI) > NiCeZrO.