Emissions of hydrogen cyanide from on-road gasoline and diesel vehicles. (April 2016)

• Record Type: Journal Article
• Authors: Moussa, Samar G.; Leithead, Amy; Li, Shao-Meng; Chan, Tak W.; Wentzell, Jeremy J.B.; Stroud, Craig; Zhang, Junhua; Lee, Patrick; Lu, Gang; Brook, Jeffery R.; Hayden, Katherine; Narayan, Julie; Liggio, John
• Is Part Of: Atmospheric environment. Volume 131(2016)
• Page Start: 185
• Page End: 195
• Publication Date: 2016-04
• Subjects: Hydrogen cyanide -- Biodiesel -- Diesel -- Gasoline -- Emission factor -- PFI -- GDI -- Biomass burning; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2016.01.050
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Hydrogen cyanide (HCN) is considered a marker for biomass burning emissions and is a component of vehicle exhaust. Despite its potential health impacts, vehicular HCN emissions estimates and their contribution to regional budgets are highly uncertain. In the current study, Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) was used to measure HCN emission factors from the exhaust of individual diesel, biodiesel and gasoline vehicles. Laboratory emissions data as a function of fuel type and driving mode were combined with ambient measurement data and model predictions. The results indicate that gasoline vehicles have the highest emissions of HCN (relative to diesel fuel) and that biodiesel fuel has the potential to significantly reduce HCN emissions even at realistic 5% blend levels. The data further demonstrate that gasoline direct injection (GDI) engines emit more HCN than their port fuel injection (PFI) counterparts, suggesting that the expected full transition of vehicle fleets to GDI will increase HCN emissions. Ambient measurements of HCN in a traffic dominated area of Toronto, Canada were strongly correlated to vehicle emission markers and consistent with regional air quality model predictions of ambient air HCN, indicating that vehicle emissions of HCN are the dominant source of exposure in urban areas. The results further indicate that additional work is required to quantify HCN emissions from the modern vehicle fleet, particularly in light of continuously changing engine, fuel and after-treatment technologies. Graphical abstract: Laboratory and ambient measurements of hydrogen cyanide (HCN) from vehicles using high resolution Proton Transfer Reaction- Time of Flight- Mass Spectrometry (PTR-ToF-MS). Highlights: HCN emission factors are reported as a function of fuel types and driving modes. HCN emissions using diesel and biodiesel fuels are 10 times less than gasoline. Gasoline direct injection (GDI) vehicles emit 10 times more HCN than port fuel injection (PFI) vehicles. Ambient measurements of HCN were conducted in traffic impacted areas in Toronto. Model predictions and ambient measurements of HCN were consistent with each other. Exposure to HCN in urban areas is dominated by vehicle emissions.