System-level techno-economic modeling of renewable synthetic LPG in long-term energy transition pathways

Renewable synthetic fuels compatible with existing energy infrastructure are increasingly recognized as a complementary pathway for decarbonizing hard-to-electrify sectors. However, the long-term role of renewable liquefied petroleum gas (rLPG) remains underexplored compared to hydrogen and biofuels. This study presents a system-level techno-economic modeling approach to assess the long-term deployment potential of rLPG under energy transition pathways. The methodology integrates a logistic growth model to represent fuel substitution dynamics, a techno-economic cost model based on Fischer–Tropsch synthesis, and a sensitivity analysis capturing the effects of fiscal and regulatory instruments. Using national-level open data, the framework is applied to three decarbonization scenarios up to 2050. Results indicate that rLPG could substitute up to 12.7 Mton of conventional fossil fuels, depending on the stringency of transition pathways. The analysis reveals a persistent production cost gap of up to 4 USD kg-1 relative to conventional LPG, which can only be closed through coordinated policy mechanisms such as carbon pricing and targeted subsidies. The proposed framework is fully transferable across national contexts and enables quantitative evaluation of synthetic fuel deployment under alternative energy transition assumptions. By combining demand dynamics with techno-economic assessment, this study provides system-level insights into the potential role of rLPG in enhancing energy security and supporting long-term decarbonization strategies.