Decarbonizing China's passenger vehicle sector with renewable hydrogen: Lower-carbon gasoline outperforms alternative fuel applications in current transition

The passenger vehicle sector is a critical yet challenging target for decarbonizing global transport systems. This study evaluates strategies to maximize renewable hydrogen's greenhouse gas (GHG) mitigation near-to mid-term potential in China's passenger vehicle sector, comparing direct use in hydrogen fuel cell vehicles (HFCEVs) with indirect pathways via lower-carbon methanol (LCM) and gasoline (LCG) synthesis. Using a fleet and energy dynamic model integrated with cradle-to-grave fuel lifecycle assessment (LCA), we analyze variations in different renewable hydrogen application pathways, and the effectiveness of promoting alternative fuel vehicles powered by hydrogen and methanol. Key findings reveal that direct hydrogen use in HFCEVs achieves limited impact, even under a rapid adoption case (12 % market share by 2040). Promoting methanol vehicles, either with or without LCM fuel supplies, risk increasing the cumulative emissions (2025–2040) by 144–672 Mt-CO2e, as linked to current coal-based methanol uses. In contrast, enabling LCM blends to decarbonize conventional gasoline ensures moderate cut by 309 Mt-CO2e, or deriving into LCG blends maximizes the reduction up to 510 Mt-CO2e, on a 2025–2040 cumulative basis. The “drop-in” gasoline fuel decarbonization strategy leverages existing infrastructure, avoids coal dependency, and decarbonizes persistent emission source from the gasoline-dominated fleet. Policy priorities include focusing on strengthening lifecycle criteria for alternative fuel uses and mandating lower-carbon gasoline supplies. This work underscores the superiority of the gasoline fuel decarbonization over alternative fuel application, charting a clear roadmap to transform current transport systems with lower-carbon, cleaner hydrogen energy.