Life Cycle Assessment of Liquid Transportation Fuel Produced by the Intensified Biogas to Liquid (IBGTL) Process

Abstract

This paper conducts a comprehensive life cycle assessment (LCA) of the intensified biogas to liquids (IBGTL) process, focusing on its global warming potential (GWP) and comparing it to alternative biogas utilization pathways. Landfill gas (LFG), derived from municipal solid waste (MSW) decomposition, contributes significantly to methane emissions and poses environmental risks. Regulatory initiatives promote LFG capture and utilization for renewable energy production. The IBGTL process, integrating bi-reforming and Fischer–Tropsch synthesis into a compact reactor design, offers advantages in reduced capital and operating costs. This study quantifies the life cycle impacts of IBGTL diesel production and benchmarks it against other LFG utilization routes, including TriFTS diesel, LFG to electricity, and LFG to compressed renewable natural gas. Using a “well-to-wheel” boundary, the study evaluates emissions from production to usage. Findings indicate substantial reductions in greenhouse gas (GHG) emissions across all LFG-to-energy pathways compared to fossil alternatives, with the most significant savings achieved by IBGTL diesel with electricity cogeneration (Scenario 4, 221 gCO₂eq/MJ reduction), followed by LFG to electricity (159 gCO₂eq/MJ reduction), TriFTS diesel (107 gCO₂eq/MJ reduction), and IBGTL diesel with material recycling (Scenario 2, 91.6 gCO₂eq/MJ reduction). Sensitivity analyses reveal nuances in emissions impacts. The results highlight the importance of process optimization and grid characteristics in shaping the environmental performance. This research contributes insights for decision-makers, informing sustainable waste management strategies and guiding future LFG-to-energy technologies.