Abstract
Heavy-duty road transport remains a challenging sector to decarbonize, as full electrification of long-distance trucking is currently constrained by limitations in energy density and charging infrastructure. Alternative fuels such as hydrogen, biodiesel, and e-fuels are thus gaining increasing attention. In parallel, the cement industry is a major source of unavoidable, process-related CO2 emissions, offering an opportunity to use captured industrial CO2 as a feedstock for e-fuel production. This study evaluates the production of e-methanol and Fischer-Tropsch (FT) diesel from captured CO2 at an Austrian cement plant as a base case. Several system configurations are analyzed, including different electricity supply options across Europe and the use of biogenic versus fossil CO2. An integrated framework combining process simulation, techno-economic analysis, and life-cycle assessment is applied to compare both fuel pathways. Results show that the climate impact of e-fuels is highly dependent on the electricity mix. When non-renewable electricity is used, climate impacts are 100-440% higher than those of fossil diesel. In contrast, a wind-based Austrian scenario achieves the lowest impact, corresponding to a 44-50% reduction compared to fossil diesel. Overall, cement-plant-based power-to-liquid concepts offer limited near- to mid-term mitigation potential under current European energy conditions and deliver climate benefits primarily when based on biogenic CO2, high process efficiencies, and low-carbon electricity. The study further highlights key differences between the fuels, with FT-diesel being a certified drop-in fuel, while e-methanol still requires technical and regulatory validation, underscoring the need for technology-specific and system-level assessments.