Integrating renewable energy sources and CO2 capture and utilisation technologies will result in energy conversion systems with negative carbon emissions (CO2 is removed from the atmosphere, reducing its concentration). Accordingly, synthetic fuels produced from renewables will gradually replace conventional fossil-based ones. This work evaluates the techno-economic implications of Synthetic Natural Gas (SNG) production from biomass (e.g., sawdust, agricultural and municipal wastes etc.) gasification with CO2 capture using gas-liquid absorption. The evaluated concept has a capacity of 500 MWth synthetic natural gas with about 60 % CO2 capture rate. The mass and energy balances of simulated integrated designs were then used to quantify the key performance indicators. A detailed techno-economic and environmental analysis underlines the promising potential of SNG production based on biomass gasification with CO2 capture feature: high cumulative energy efficiency (about 69 %), low specific CO2 emissions (up to 3 kg/MWh as process emission and negative emissions for the overall system), the co-generation capability of SNG and decarbonized power as well as improved economic indicators in terms of capital investment, operational costs and SNG production cost.