Catalytic conditioning of synthesis gas produced by biomass gasification

The catalytic steam reforming of aromatic hydrocarbons in a background of synthesis gas was investigated for two catalysts. A proprietary non-nickel based catalyst, designated DN-34, and a commercial nickel steam reforming catalyst ICI 46-1 were tested. Statistically designed experiments were used to examine the effects of temperature, space velocity and percent of steam in the feed on catalyst performance. All experiments were performed in a plug-flow micro-reactor interfaced with a molecular beam mass spectrometer. The catalyst DN-34 was also tested in slip-stream fluidized bed reactors attached to a 9 tonne day−1 indirectly heated biomass gasifier at Battelle Columbus Laboratory. DN-34 was found to be effective for destroying a variety of aromatic hydrocarbons found in biomass gasifier tar in both the micro-reactor and gasifier-scale experiments. DN-34 also exhibited significant water-gas shift activity but was unsatisfactory for methane destruction. ICI 46-1 exhibited excellent methane steam reforming activity. A process is suggested that uses DN-34 to steam reform tar and perform the water-gas shift, followed by a second reactor with ICI 46-1 to reform methane. Differences and similarities with other dual-bed processes described in the literature are discussed.