부산대학교 도서관

• Two-stage methanation is studied for a syngas generated from biomass gasification. • The need of adding green H2 produced from renewable sources was assessed. • A final CH4 purity of 78 vol% is produced due to poor CO2 conversion. • Alternative conditions and/or schemes would raise the purity for this specific route. Synthetic Natural Gas (SNG) produced from renewable sources constitutes a solution for the transition to net-zero emissions for natural gas relying sectors. From the different biomass-to-SNG routes, the gasification of biomass to produce a syngas that is further converted into SNG has a large potential in a near future. In this work, the methanation process under quasi commercial conditions was demonstrated for a syngas generated from biomass gasification. The influence of process variables like pressure, steam/CO ratio and syngas composition (i.e. content of CO 2 , CH 4 and light hydrocarbons) were analyzed to evaluate the maximum CH 4 purity achieved in a commonly used two-step methanation process. Moreover, the need of adding green H 2 produced from renewable sources was studied to adjust the H 2 /CO/CO 2 ratio for methanation. A product gas with 78 %vol. CH 4 was produced using a commercial Ni-based catalyst, being the conversion of CO 2 the limiting factor towards the fulfilment of a higher CH 4 content (only 37 % of CO 2 conversion was reached in the second methanation reactor at 270 °C, 4 bar and 2140 h−1 of gas space velocity). Alternative operating conditions and/or intensified process schemes stand as the most promising alternatives for the conversion of syngas into high purity SNG. [ABSTRACT FROM AUTHOR]