Tri-reforming of Methane over Ni Catalysts for CO_2 Conversion to Syngas With Desired H_2/CO Ratios Using Flue Gas of Power Plants Without CO_2 Separation

摘要

Tri-reforming is a novel process concept proposed for effective conversion and utilization of CO_2 in the flue gases from fossil fuel-based power plants (C. Song, Chemical Innovation, 2001, 31, 21-26). The CO_2, H_2O, and O_2 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 CO_2 reforming, steam reforming, and partial oxidation of natural gas. It can produce synthesis gas (CO+H_2) with H_2/CO ratios (1.5-2.0) and could eliminate carbon formation which is a serious problem in the CO_2 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% CH_4 conversion and over 80% CO_2 conversion can be achieved by using certain supported transition metal catalysts such as Ni supported on an oxide substrate.