Evaluation of Emissions from an EMD567 Switcher Locomotive with 100% Soy Methyl Ester Biodiesel
Jeremy Rochussen, Rickey Lee, ANAND KUMAR, Hamed Nikookar, Nadine Borduas-Dedekind, Steven Rogak, Patrick Kirchen,
University of British Columbia Abstract Number: 697
Working Group: Combustion
AbstractEngine exhaust is considered a major source of air pollutants which have adverse effects on human health and climate. Biodiesel is drawing attention as a part of solution to meet the demand for renewable transport fuels and to reduce greenhouse gas emissions. However, the effect of biodiesel varies for various exhaust pollutants depending on type of engine, engine speed and load conditions, etc. We investigated the relative change in tank-to-stack emissions from a legacy switching electro-motive diesel engine (Pre-Tier 0, EMD SW900) when fed with: B5 (standard petroleum diesel with up to 5% biodiesel) and B100 (low life-cycle carbon intensity, 100% Soy Methyl Ester biodiesel). This first of its kind field study was conducted in April 2023 at the New Westminster (Canada) yard location of Southern Railway of British Columbia. All tests were performed on a stationary locomotive engine at varying load conditions. Preliminary analysis suggests 51% - 83% lower black carbon emission factor, yet 14% - 26% higher NOx emission factor for B100 with respect to B5. Particulate size distributions show that both fuels generate submicron particles below 300 nm in diameter (mode 50 – 100 nm). Both fuels show similar total number concentrations at low-mid load conditions, but increase to ≈1.5 times for B5 compared to B100 at high load conditions. Interestingly, the number concentrations are at least an order of magnitude (10 – 80 times) lower for both fuels across most loading conditions when the particles are sampled through a catalytic stripper, implying a major contribution of volatile organics. This result also translates into bimodal size distributions with modes observed at ≈15 nm and ≈100 nm. Use of biodiesel as fuel could entail increase of ozone precursors albeit with a reduction in elemental carbon, a global warming agent. Oxidation catalysts could allow for effective control of organic carbon.