Modelling and life cycle assessment of biomass-based synthetic natural gas production

Meeting Austria's 2040 carbon neutrality target requires a rapid transition to industrial-scale processes. Biomass-based technologies are pivotal in this shift, as they reduce reliance on fossil resources while producing high-value products. This study models and evaluates the potential environmental impacts of producing biomass-based synthetic natural gas (Bio-SNG) through gasification and methanation, incorporating scenario analysis. Seven impact categories were assessed: acidification potential, eutrophication, land use, fossil resource use, water use, particulate matter, and climate change. Among the Bio-SNG scenarios, the Bio-SNG-W scenario, which utilises wind-generated electricity, shows the lowest impacts across climate and most non-climate categories. Using the IPCC, 2021 methodology, the base case (bio-SNG) estimated net global warming emissions of 41 kgCO2 eq./MWhBio-SNG, mostly due to wood chip preparation and electricity consumption. Thus, when wind power is used as the electricity source (Bio-SNG-W), the greenhouse gas emissions reduce to 25 kgCO2 eq./MWhBio-SNG. In comparison, the emissions for natural gas production and processing, excluding the higher impact use phase, stand at 16 kgCO2 eq./MWhNG. Except for fossil resource use, Bio-SNG-related scenarios show higher emissions than their fossil-based counterpart, underscoring these processes' resource and energy intensity as well as showing a potential burden-shifting effect.