Emissions and cost impacts of train configuration and biofuel blends in freight rail operations: A simulation-based assessment

This study establishes a framework for evaluating the fuel consumption of diesel-electric locomotives by examining the key factors affecting their energy intensity and associated variabilities within the U.S. freight railroad sector. By analyzing the impact of train configuration, routes, and commodity types on fuel consumption per freight ton-mile, this study highlights the complex interactions that drive variability in energy use per ton-mile. Simulations using the OneTrain model indicate that regular freight trains operating between Kansas City and Los Angeles achieve an average fuel efficiency of 478 revenue ton-miles per gallon of diesel, which is consistent with previously reported values for U.S. freight rail. For intermodal trains operating on the Southern Transcon corridor, energy intensity ranges from 604 to 887 Btu per revenue ton-mile. This study also assesses the impact of drop-in biofuels, specifically biodiesel and renewable diesel, on the well-to-wheels emissions of freight transportation by rail. Using environmental life cycle analysis and techno-economic analysis, several intermodal train configurations and feedstock options are evaluated. Our results show that the cost of avoided greenhouse gas emissions varies between $43–91/MT CO 2 e, depending on fuel blend ratios and feedstock types. Renewable diesel from sewage sludge offers the most cost-effective emissions reductions, $42.95/MT CO 2 e, while biodiesel presents higher costs per unit of avoided emissions, $90.97/MT CO 2 e.