scholarly journals Real World Vehicle Emission Factors for Black Carbon Derived from Longterm In-Situ Measurements and Inverse Modelling

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Anne Wiesner ◽  
Sascha Pfeifer ◽  
Maik Merkel ◽  
Thomas Tuch ◽  
Kay Weinhold ◽  
...  
Keyword(s):  
Black Carbon ◽  
Real World ◽  
Direct Injection ◽  
Urban Pollution ◽  
Pollutant Dispersion ◽  
Road Transport ◽  
Emission Factors ◽  
Climate Modelling ◽  
Emission Model ◽  
Local Conditions

Black carbon (BC) is one of the most harmful substances within traffic emissions, contributing considerably to urban pollution. Nevertheless, it is not explicitly regulated and the official laboratory derived emission factors are barely consistent with real world emissions. However, realistic emission factors (EFs) are crucial for emission, exposure, and climate modelling. A unique dataset of 10 years (2009–2018) of roadside and background measurements of equivalent black carbon (eBC) concentration made it possible to estimate real world traffic EFs and observe their change over time. The pollutant dispersion was modelled using the Operational Street Pollution Model (OSPM). The EFs for eBC are derived for this specific measurement site in a narrow but densely trafficked street canyon in Leipzig, Germany. The local conditions and fleet composition can be considered as typical for an inner-city traffic scenario in a Western European city. The fleet is composed of 22% diesel and 77% petrol cars in the passenger car segment, with an unknown proportion of direct injection engines. For the mixed fleet the eBC EF was found to be 48 mg km−1 in the long-term average. Accelerated by the introduction of a low emission zone, the EFs decreased over the available time period from around 70 mg km−1 to 30–40 mg km−1. Segregation into light (<3.5 t) and heavy (>3.5 t) vehicles resulted in slightly lower estimates for the light vehicles than for the mixed fleet, and one order of magnitude higher values for the heavy vehicles. The found values are considerably higher than comparable emission standards for particulate matter and even the calculations of the Handbook Emission Factors for Road Transport (HBEFA), which is often used as emission model input.

scholarly journals Russia's black carbon emissions: focus on diesel sources

2016 ◽  
Vol 16 (17) ◽  
pp. 11267-11281 ◽  
Author(s):  
Nazar Kholod ◽  
Meredydd Evans ◽  
Teresa Kuklinski
Keyword(s):  
Black Carbon ◽  
Road Transport ◽  
Emission Factors ◽  
Diesel Emissions ◽  
Polar Regions ◽  
Emission Model ◽  
Road Vehicles ◽  
Activity Data ◽  
Diesel Vehicles ◽  
Model Computer

Abstract. Black carbon (BC) is a significant climate forcer with a particularly pronounced forcing effect in polar regions such as the Russian Arctic. Diesel combustion is a major global source of BC emissions, accounting for 25–30 % of all BC emissions. While the demand for diesel is growing in Russia, the country's diesel emissions are poorly understood. This paper presents a detailed inventory of Russian BC emissions from diesel sources. Drawing on a complete Russian vehicle registry with detailed information about vehicle types and emission standards, this paper analyzes BC emissions from diesel on-road vehicles. We use the COPERT emission model (COmputer Programme to calculate Emissions from Road Transport) with Russia-specific emission factors for all types of on-road vehicles. On-road diesel vehicles emitted 21 Gg of BC in 2014: heavy-duty trucks account for 60 % of the on-road BC emissions, while cars represent only 5 % (light commercial vehicles and buses account for the remainder). Using Russian activity data and fuel-based emission factors, the paper also presents BC emissions from diesel locomotives and ships, off-road engines in industry, construction and agriculture, and generators. The study also factors in the role of superemitters in BC emissions from diesel on-road vehicles and off-road sources. The total emissions from diesel sources in Russia are estimated to be 49 Gg of BC and 17 Gg of organic carbon (OC) in 2014. Off-road diesel sources emitted 58 % of all diesel BC in Russia.

scholarly journals Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

2015 ◽  
Vol 8 (3) ◽  
pp. 2881-2912 ◽  
Author(s):  
J. M. Wang ◽  
C.-H. Jeong ◽  
N. Zimmerman ◽  
R. M. Healy ◽  
D. K. Wang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Black Carbon ◽  
Time Resolution ◽  
Real World ◽  
Vehicle Emissions ◽  
Particle Number ◽  
Emission Factors ◽  
Air Pollutant ◽  
Automated Identification ◽  
Vehicle Fleet

Abstract. An automated identification and integration method has been developed to investigate in-use vehicle emissions under real-world conditions. This technique was applied to high time resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada during four seasons, through month-long campaigns in 2013–2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg−1 and 7.7 × 1014 kg−1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25%) contributed significantly to total fleet emissions; 95, 93, 76, and 75% for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter. However, regulatory strategies to more efficiently target multi-pollutants mixtures may be better developed by considering the co-emitted pollutants as well.

scholarly journals Trends in black carbon and size-resolved particle number concentrations and vehicle emission factors under real-world conditions

2017 ◽  
Vol 165 ◽  
pp. 155-168 ◽  
Author(s):  
Patricia Krecl ◽  
Christer Johansson ◽  
Admir Créso Targino ◽  
Johan Ström ◽  
Lars Burman
Keyword(s):  
Black Carbon ◽  
Real World ◽  
Particle Number ◽  
Emission Factors ◽  
Vehicle Emission

scholarly journals Elucidating real-world vehicle emission factors from mobile measurements over a large metropolitan region: a focus on isocyanic acid, hydrogen cyanide, and black carbon

2018 ◽  
Author(s):  
Sumi N. Wren ◽  
John Liggio ◽  
Yuemei Han ◽  
Katherine Hayden ◽  
Gang Lu ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Real World ◽  
Hydrogen Cyanide ◽  
Emission Factors ◽  
Interquartile Range ◽  
Isocyanic Acid ◽  
Vehicle Emission ◽  
Vehicular Emissions ◽  
The Impact

Abstract. A mobile laboratory equipped with state-of-the-art gaseous and particulate instrumentation was deployed across the Greater Toronto Area during two seasons. A high-resolution time-of-flight mass spectrometer (HR-TOF-CIMS) measured isocyanic acid (HNCO) and hydrogen cyanide (HCN), and a high-sensitivity laser-induced incandescence (HS-LII) instrument measured black carbon (BC). Results indicate that on-road vehicles are a clear source of HNCO and HCN, and that their impact is more pronounced in the winter, when influences from biomass burning and secondary photochemistry are weakest. Plume-based and time-based algorithms were developed to calculate fleet-average vehicle emission factors (EF); the algorithms were found to yield comparable results, depending on the pollutant identity. With respect to literature EFs for benzene, toluene, C2 benzene (sum of m,p,o-xylenes and ethylbenzene), nitrogen oxides, particle number concentration (PN), and black carbon, the calculated EFs were characteristic of a relatively clean vehicle fleet dominated by light-duty vehicles. Our fleet-average EF for BC (median: 25 mg kgfuel−1, interquartile range: 10–76 mg kgfuel−1) suggests that overall vehicular emissions of BC have decreased over time. However, the distribution of EFs indicates that a small proportion of high-emitters continue to contribute disproportionately to total BC emissions. We report the first fleet-average EF for HNCO (median: 2.3 mg kgfuel−1, interquartile range: 1.4–4.2 mg kgfuel−1) and HCN (median: 0.52 mg kgfuel−1, interquartile range: 0.32–0.88 mg kgfuel−1). The distribution of the estimated EFs provides insight into the real-world variability of HNCO and HCN emissions, and constrains the wide range of literature EFs obtained from prior dynamometer studies. Our results demonstrate that although biomass burning is a dominant source of both air toxics on a national scale, vehicular emissions play an increasingly important role at a local scale, especially in heavily-trafficked urban areas. The impact of vehicle emissions on urban HNCO levels can be expected to be further enhanced if secondary HNCO formation from vehicle exhaust is considered.

scholarly journals Elucidating real-world vehicle emission factors from mobile measurements over a large metropolitan region: a focus on isocyanic acid, hydrogen cyanide, and black carbon

2018 ◽  
Vol 18 (23) ◽  
pp. 16979-17001 ◽  
Author(s):  
Sumi N. Wren ◽  
John Liggio ◽  
Yuemei Han ◽  
Katherine Hayden ◽  
Gang Lu ◽  
...  
Keyword(s):  
Black Carbon ◽  
Real World ◽  
Hydrogen Cyanide ◽  
Emission Factors ◽  
Metropolitan Region ◽  
Isocyanic Acid ◽  
Vehicle Emission ◽  
Ionization Mass ◽  
Wide Range ◽  
The Impact

Abstract. A mobile laboratory equipped with state-of-the-art gaseous and particulate instrumentation was deployed across the Greater Toronto Area (GTA) during two seasons. A high-resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) measured isocyanic acid (HNCO) and hydrogen cyanide (HCN), and a high-sensitivity laser-induced incandescence (HS-LII) instrument measured black carbon (BC). Results indicate that on-road vehicles are a clear source of HNCO and HCN and that their impact is more pronounced in the winter, when influences from biomass burning (BB) and secondary photochemistry are weakest. Plume-based and time-based algorithms were developed to calculate fleet-average vehicle emission factors (EFs); the algorithms were found to yield comparable results, depending on the pollutant identity. With respect to literature EFs for benzene, toluene, C2 benzene (sum of m-, p-, and o-xylenes and ethylbenzene), nitrogen oxides, particle number concentration (PN), and black carbon, the calculated EFs were characteristic of a relatively clean vehicle fleet dominated by light-duty vehicles (LDV). Our fleet-average EF for BC (median: 25 mg kgfuel-1; interquartile range, IQR: 10–76 mg kgfuel-1) suggests that overall vehicular emissions of BC have decreased over time. However, the distribution of EFs indicates that a small proportion of high-emitters continue to contribute disproportionately to total BC emissions. We report the first fleet-average EF for HNCO (median: 2.3 mg kgfuel-1, IQR: 1.4–4.2 mg kgfuel-1) and HCN (median: 0.52 mg kgfuel-1, IQR: 0.32–0.88 mg kgfuel-1). The distribution of the estimated EFs provides insight into the real-world variability of HNCO and HCN emissions and constrains the wide range of literature EFs obtained from prior dynamometer studies. The impact of vehicle emissions on urban HNCO levels can be expected to be further enhanced if secondary HNCO formation from vehicle exhaust is considered.

scholarly journals Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

2015 ◽  
Vol 8 (8) ◽  
pp. 3263-3275 ◽  
Author(s):  
J. M. Wang ◽  
C.-H. Jeong ◽  
N. Zimmerman ◽  
R. M. Healy ◽  
D. K. Wang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Black Carbon ◽  
Time Resolution ◽  
Real World ◽  
Vehicle Emissions ◽  
Particle Number ◽  
Emission Factors ◽  
Air Pollutant ◽  
Automated Identification ◽  
Vehicle Fleet

Abstract. An automated identification and integration method has been developed for in-use vehicle emissions under real-world conditions. This technique was applied to high-time-resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada, during four seasons, through month-long campaigns in 2013–2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number; black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline-dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg fuel−1 and 7.5 × 1014 # kg fuel−1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25 %) contributed significantly to total fleet emissions: 100, 100, 81, and 77 % for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter; however, regulatory strategies to more efficiently target multi-pollutant mixtures may be better developed by considering the co-emitted pollutants as well.

scholarly journals Russia's black carbon emissions: focus on diesel sources

2016 ◽  
Author(s):  
N. Kholod ◽  
M. Evans ◽  
T. Kuklinski
Keyword(s):  
Black Carbon ◽  
Emission Factors ◽  
Diesel Emissions ◽  
Polar Regions ◽  
Emission Model ◽  
Commercial Vehicles ◽  
Road Vehicles ◽  
Activity Data ◽  
Diesel Vehicles

Abstract. Black carbon (BC) is a significant climate forcer with a particularly pronounced forcing effect in polar regions, like the Russian Arctic. Diesel combustion is a major global source of BC emissions, accounting for 25–30 % of all BC emissions. The demand for diesel is growing in Russia, but Russian diesel emissions are poorly understood. This paper presents a detailed inventory of Russian BC emissions from diesel sources. Drawing on a complete Russian vehicle registry with detailed information about vehicle types and emission standards, this paper analyzes BC emissions from diesel on-road vehicles. We use the COPERT emission model with Russia-specific emission factors for all types of on-road vehicles. On-road diesel vehicles emitted 21 Gg of BC in 2014; heavy-duty trucks account for 70 % of the on-road BC emissions, while cars represent only 4 % (light commercial vehicles and buses account for the remainder). Using Russian activity data and fuel-based emission factors, the paper also presents BC emissions from diesel locomotives and ships, off-road engines in industry, construction and agriculture, and from diesel generators. The study also factors in the role of superemitters in BC emissions from diesel on-road vehicles and off-road sources. The total emissions from diesel sources in Russia are estimated to be 48 Gg of BC and 16 Gg of OC in 2014. Off-road diesel sources emitted 57 % of all diesel BC in Russia.

scholarly journals On the Experimental, Numerical and Data-Driven Methods to Study Urban Flows

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1310
Author(s):  
Pablo Torres ◽  
Soledad Le Clainche ◽  
Ricardo Vinuesa
Keyword(s):  
Physical Phenomenon ◽  
Urban Pollution ◽  
Pollutant Dispersion ◽  
Urban Environments ◽  
Machine Learning Algorithms ◽  
Data Driven ◽  
Thermal Fields ◽  
Use Of Data ◽  
Sustainability Challenges ◽  
New Research

Understanding the flow in urban environments is an increasingly relevant problem due to its significant impact on air quality and thermal effects in cities worldwide. In this review we provide an overview of efforts based on experiments and simulations to gain insight into this complex physical phenomenon. We highlight the relevance of coherent structures in urban flows, which are responsible for the pollutant-dispersion and thermal fields in the city. We also suggest a more widespread use of data-driven methods to characterize flow structures as a way to further understand the dynamics of urban flows, with the aim of tackling the important sustainability challenges associated with them. Artificial intelligence and urban flows should be combined into a new research line, where classical data-driven tools and machine-learning algorithms can shed light on the physical mechanisms associated with urban pollution.

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