Locomotive Biofuel Study: Preliminary Study of the Use and Effects of Biodiesel in Locomotive Engines

Section 404 of the Passenger Rail Investment and Improvement Act (PRIIA), 2008, mandated that the Federal Railroad Administration (FRA) undertake a Locomotive Biofuel Study to investigate the feasibility of using biofuel blends as locomotive engine fuel. This report summarizes three research initiatives undertaken by FRA to assess the viability of biodiesel as an alternative fuel for locomotives. The first initiative consisted of using a 20 percent blend of biodiesel in a passenger locomotive in revenue service to study air emissions and engine wear. The second initiative measured the emissions of Tier 1+ and Tier 2 locomotives operating on 5 percent and 20 percent blends of biodiesel, respectively. Those emissions were compared with those generated by conventional diesel fuel. The third initiative investigated the availability of biodiesel, rail yard and revenue service engine performance and emissions on various blends of biodiesel, as well as the practicability of using an alternative method to measure those emissions. The results from these research initiatives show that while it may be feasible to use biodiesel in blends of up to 20 percent in locomotive engines and reveal some impact on emissions, additional research is needed to understand the long term effects of high blends of biodiesel on locomotive engine components.