Fluidized Bed Methanation of Wood-Derived Producer Gas for the Production of Synthetic Natural Gas

For proving the concept of SNG production from wood gasification derived producer gas under real conditions, a mobile bench-scale fluidized bed reactor setup was fed with producer gas of the Fast Internally Circulating Bed (FICFB) wood gasifier in Giissing, Austria. In long-term experiments, it could be shown that the fluidized methanation catalyst allows for constantly high CO-conversion (about 98%) and CH4 concentration (about 40%) in the outlet. A similar experiment was conducted in a bench-scale reactor that allows for the measurement of axial gas phase concentration profiles by means of a movable sampling tube. It could be shown that under the chosen operation conditions, all three important reactions (methanation, water gas shift, and reforming of olefins) take place very rapidly in a region close to the reactor inlet. In the rest of the bed, the reaction of reactants transferred from the bubbles to the catalyst containing dense phase of the fluidized bed reactor is dominant.