Life Cycle Analysis (LCA) of Hydrogen Boosted Biomethanization with Alternative Power Scenarios

This study aimed to assess the environmental impacts of biogas-to-biomethane conversion using ex-situ (hydrogenotrophic) methods, with hydrogen (H₂) sourced from alternative production lines, electricity from the national grid (base scenario), solar power via photovoltaic panels (scenario 1), and wind power (scenario 2). Life Cycle Analysis (LCA) was conducted for scenarios using different energy sources for H₂ production. The results were evaluated using the impact assessment method ReCiPe 2016 Midpoint (H) V.1.02, considering 18 impact categories. A model was developed based on production data from a real biogas plant in İzmir, where activity data were obtained directly from the plant's logs. The LCA analysis revealed that hydrogen production from grid electricity resulted in 10.3 kg CO₂ eq in the climate change category, which decreased to 1.27 kg CO₂ eq when using solar energy. The overall carbon footprint decreased from 8.66 kg CO₂ eq to -0.494 kg CO₂ eq. In the second scenario, hydrogen was produced using wind energy rather than grid electricity. The analysis showed that hydrogen production from grid electricity resulted in 10.3 kg CO₂ eq in the climate change category, while using wind energy reduced this to 0.199 kg CO₂ eq. According to the LCA results, energy sources and electricity demand play a crucial role in determining GHG emissions, and the LCA can assist companies and governments in decision-making and policy development.