Abstract: Abstract: Natural gas is one of the clean primary energy sources and high-quality chemical raw materials. Technology of methane production from biomass thermo-chemical gasification (biomass-to-SNG) is one of the most important pathways to produce synthetic natural gas (SNG) to substitute diminishing natural gas. In the biomass-to-SNG process, the biomass is first converted into product gas through biomass gasification. Then, the product gas full of CO and H2 is synthesized into methane through the methanation processes after some proper cleaning and conditioning processes. Finally, the crude synthetic natural gas is upgraded with CO2 removal and gas dehydration. In the whole biomass-to-SNG process, the methanation process of product gas is a key step. A pressurized fluidized bed methanation reactor system was designed and constructed, which is mainly composed of a main reactor and auxiliary equipments. An experimental study of methane production from product gas was carried out on this methantion reactor system with the commercial methanation catalyst as bed material. The Energy Dispersive Spectrometer analysis indicates that the methanation catalyst contains high nickel content and was squashed into small particles for the study. Then, the effects of methanation temperature, pressure, space velocity, and ratio of H2 to CO on the performance indexes (i.e. methane formation rate and CO conversion rate) were investigated. The results show that methane is efficiently produced on this pressurized fluidized bed methanation reactor system and the typical methane formation rate is higher than 3.2 mol/(L·h) while the CO conversion rate is more than 80%. Higher methanation temperature is favored to the methanation process and the methane formation rate and CO conversion rate achieve the maximum values at the methanation temperature about 350℃. However, when the methanation temperature is higher than 350℃, the methane formation rate and CO conversion rate decline slowly since the methanation reactions are exothermic reactions and high temperatures are thus unfavorable to the methanation reactions and may also cause the catalyst to deactivate because of carbon deposition and sintering of catalyst. The methanation process is also benefited from higher methanation pressure since the methanation reactions are volume-contraction reactions. The methane formation rate and CO conversion rate increase with the rise of methanation pressure, especially when the methanation pressure is higher than 0.3 MPa. The methanation process is heavily affected by the space velocity, too. With the increase of space velocity, the methane formation rate increases while the CO conversion rate declines accordingly. The ratio of H2 to CO is another key influencing factor in the methanation process. With the rise of the ratio of H2 to CO, the methane formation rate increases accordingly, while the CO conversion rate rises and reaches the highest values when the ratio is about 3 and then the CO conversion rate maintains a high value. In short, to achieve higher methane formation rate and CO conversion rate, suitable methanation temperature is about 350℃, space velocity is around 10 000 h-1, the ratio of H2 to CO is around 3, while the methanation pressure is 0.3 MPa, taking the biomass utilization scale and investment costs into account. These results may lay a solid foundation for further studies of biomass-to-SNG process