Effect of Biodiesel Fuels on Real-World Emissions of Passenger Locomotives

Abstract

Few data are available regarding the effect of biodiesel on exhaust emission rates of two-stroke engines used in many passenger locomotives. Using a portable emissions measurement system (PEMS), duty cycle average nitrogen oxides (NO), hydrocarbons (HC), carbon monoxide (CO), particulate matter (PM), and carbon dioxide (CO) emission rates were measured for three locomotives operating on ultra-low sulfur diesel (ULSD) and soy-based B10, B20, and B40 biodiesel blends. Measurements were conducted in the rail yard (RY) and over-the-rail (OTR) during passenger service. Compared to ULSD, B20 biodiesel had statistically significant average emission rate reductions in the RY of 58% for CO, 45% for PM, and 6% CO and OTR of 59% for HC, 50% for CO, 26% for PM, and 5% for CO. The average differences in NO emission rates for both the RY and OTR, and HC in the RY, were not statistically significant. The OTR findings typically agreed qualitatively with the RY findings; however, OTR provides a better basis for estimating the real-world impact of fuel switching. The results indicate substantial potential to reduce in-use locomotive emissions for existing older locomotives, with the exception of NO.

Soy Biodiesel Exhaust is More Toxic than Mineral Diesel Exhaust in Primary Human Airway Epithelial Cells

“…Combustion of both diesel and biodiesel results in the generation of toxic gases and respiratory irritants such as carbon dioxide, carbon monoxide, nitrogen oxides and sulfur dioxide . The results of previous studies comparing the gaseous outputs of the two exhausts vary considerably 4,9,33,34 . The majority have found that biodiesel exhaust contains more NOx as well as a decrease in the average size of the particulate matter 4,7,8 and this study has found similar results.…”

Characterizing Fuel Use and Emission Hotspots for a Diesel-Operated Passenger Rail Service

“…The SEMTECH-DS measures NO, NO 2 , and NO x concentrations based on the same detection methods as specified in 40 CFR 1065 Subpart J . The bias correction factor for each throttle notch position of each locomotive was estimated as the ratio of notch-average NO x /NO concentrations measured using a SEMTECH-DS PEMS. ,,, For several heavy-duty diesel engines, the laser light scattering-based PM concentrations were correlated with the FRM. The slope of linear regression of FRM versus laser light scattering was reported as 5. − Thus, laser light scattering is typically biased low by a factor of 5.…”

Quantification of Energy Saving Potential for A Passenger Train Based on Inter-Run Variability in Speed Trajectories

“…Exhaust concentrations and engine activity data were recorded every second. Details of the installation are described elsewhere ( 8 – 10 ).…”

“…To quantify energy consumption of individual trips, field measurements or model simulations can be used ( 7 ). Field measurements have been conducted using a portable emission measurement system (PEMS) for diesel-electric locomotives ( 8 , 9 ). Field measurements using PEMS provide comparable results to federal reference methods (FRMs) based on engine dynamometer measurements ( 10 ).…”