title: Field Measurements of Gasoline Direct Injection Emission Factors: Spatial and Seasonal Variability.
abstract: Four field campaigns were conducted between February 2014 and January 2015 to measure emissions from light-duty gasoline direct injection (GDI) vehicles (2013 Ford Focus) in an urban near-road environment in Toronto, Canada. Measurements of CO2, CO, NOx, black carbon (BC), benzene, toluene, ethylbenzene-xylenes (BTEX), and size-resolved particle number (PN) were recorded 15 m from the roadway and converted to fuel-based emission factors (EFs). Other than for NOx and CO, the GDI engine had elevated emissions compared to the Toronto fleet, with BC EFs in the 73rd percentile, BTEX EFs in the 80-90th percentile, and PN EFs in the 75th percentile during wintertime measurements. Additionally, for three campaigns, a second platform for measuring PN and CO2 was placed 1.5-3 m from the roadway to quantify changes in PN with distance from point of emission. GDI vehicle PN EFs were found to increase by up to 240% with increasing distance from the roadway, predominantly due to an increasing fraction of sub-40 nm particles. PN and BC EFs from the same engine technology were also measured in the laboratory. BC EFs agreed within 20% between the laboratory and real-world measurements; however, laboratory PN EFs were an order of magnitude lower due to exhaust conditioning.
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Naomi
authors.initials: N
authors.lastname: Zimmerman
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Cheol-Heon
authors.initials: CH
authors.lastname: Jeong
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto , Toronto, Ontario M5S3G8, Canada.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ramos
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Nathan
authors.initials: N
authors.lastname: Hilker
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Healy
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Kelly
authors.initials: K
authors.lastname: Sabaliauskas
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto , Toronto, Ontario M5S3G8, Canada.
authors.forename: James S
authors.initials: JS
authors.lastname: Wallace
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S3E5, Canada.
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Evans
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002170:Canada; D002245:Carbon Dioxide / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005742:Gasoline; D018986:Motor Vehicles; D009589:Nitrogen Oxides / Q000032:analysis; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D012621:Seasons; D053260:Soot / Q000032:analysis; D062211:Spatio-Temporal Analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D005742:Gasoline; D009589:Nitrogen Oxides; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions; D002245:Carbon Dioxide