Well–to–Wheel greenhouse gas emissions of E-gasoline: Insights from the South Korean case for energy-importing countries

This study conducts a comprehensive life cycle assessment (LCA) of electricity-based gasoline (E-gasoline) to evaluate its potential as a decarbonization strategy in regions where internal combustion engine vehicles (ICEVs) and hybrid electric vehicles (HEVs) remain prevalent, such as South Korea. The analysis investigates the influence of carbon capture sources and upstream emissions associated with electricity and hydrogen production on the well-to-pump (WTP) greenhouse gas (GHG) emissions of E-gasoline. When synthesized via direct air capture (DAC), green hydrogen, and renewable electricity, WTP GHG emissions can reach –60.60 kg-CO₂-eq./GJ, which is substantially lower than the 12.23 kg-CO₂-eq./GJ of conventional petroleum-based gasoline. This study also examines how WTP emissions vary depending on different ISO-compliant allocation methods and system expansion approaches when carbon is captured from plants producing another product, such as natural gas combined cycle (NGCC) and steam methane reforming (SMR) plants, revealing significant emission differences based on the chosen methodology. To assess E-gasoline’s competitiveness as a low-carbon fuel, the study compares the well-to-wheel (WTW) emissions of ICEVs and HEVs utilizing E-gasoline against those of battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs). Results indicate that for HEVs to attain WTW emissions parity with BEVs, the WTP emissions of E-gasoline must be –0.18 kg-CO₂-eq./GJ or lower, a threshold achievable when utilizing green or blue hydrogen and clean electricity. Furthermore, alignment with the European Union Renewable Energy Directive (EU RED), which stipulates a threshold of 28.2 g-CO₂-eq./MJ, necessitates comprehensive upstream decarbonization. The methodological framework presented in this study for determining WTP GHG emission can be applied by countries in similar circumstances as they develop energy policies to support the successful deployment of E-gasoline as a viable low-carbon fuel in transport sectors.