Tri-reforming of methane over Ni catalysts for CO₂ conversion to Syngas with desired H₂CO ratios using flue gas of power plants without CO₂ separation

Tri-reforming is a novel process concept proposed for effective conversion and utilization of CO₂ in the flue gases from fossil fuel-based power plants (C. Song, Chemical Innovation, 2001, 31, 21-26). The CO₂, H₂O, and O₂ in the flue gas need not be pre-separated because they will be used as co-reactants for tri-reforming of natural gas. The tri-reforming is a synergetic combination of CO₂ reforming, steam reforming, and partial oxidation of natural gas. It can produce synthesis gas (CO+H₂) with H₂/CO ratios (1.5-2.0) and could eliminate carbon formation which is a serious problem in the CO₂ reforming of methane. These two advantages have been demonstrated by a laboratory experimental study of tri-reforming at 850°C. Both thermodynamic analysis and the experimental testing in a fixed-bed flow reactor showed that over 95% CH₄ conversion and over 80% CO₂ conversion can be achieved by using certain supported transition metal catalysts such as Ni supported on an oxide substrate.