Toward Sustainable Rail Transport: Well-to-Wheel Analysis of Locomotive Emissions Using Alternative Fuels

Abstract

Diesel-electric locomotives remain the dominant mode of freight rail traction in many countries, relying heavily on petroleum-based fuels and significantly contributing to greenhouse gas and pollutant emissions. This study introduces the Well-to-Wheel Locomotive Emissions Assessment framework, grounded in ISO 14040/44 standards, offering a structured, scalable, and globally replicable method for assessing railway fuel strategies. Using real-world data from the Vitória-Minas Railway, five fuel scenarios were modeled, including blends of petroleum diesel (B10), biodiesel (B25), and liquefied natural gas (LNG). Although developed for Brazil, the framework accommodates diverse locomotive types, regional fuel chains, and operational conditions, making it suitable for application in other national contexts. The results showed that the most favorable scenario, an 80% LNG and 20% B25 blend, achieved reductions of 24.93% in CO₂e, 36.09% in NOx, 45.23% in particulate matter, and 63.05% in SO₂ emissions compared with current operations. These findings could offer valuable guidance for transport authorities, infrastructure operators, and energy policy planners worldwide. By integrating upstream and downstream emissions, this research delivers practical, internationally relevant insights into cleaner rail transport solutions and advances the application of life cycle thinking in the freight sector.