scholarly journals Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

2015 ◽  
Vol 8 (1) ◽  
pp. 43-55 ◽  
Author(s):  
I. Ježek ◽  
L. Drinovec ◽  
L. Ferrero ◽  
M. Carriero ◽  
G. Močnik

Abstract. We have used two methods for measuring emission factors (EFs) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured, and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EFs of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars; hence, we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, and we rather describe the vehicle EF with a characteristic value and a super emission tail.

2014 ◽  
Vol 7 (6) ◽  
pp. 5423-5455 ◽  
Author(s):  
I. Ježek ◽  
L. Drinovec ◽  
L. Ferrero ◽  
M. Carriero ◽  
G. Močnik

Abstract. We have used two methods for measuring emission factors (EF) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured; and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EF of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars, hence we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, rather we describe the vehicle EF with a characteristic value and a "super emission" tail.


2015 ◽  
Vol 8 (3) ◽  
pp. 2881-2912 ◽  
Author(s):  
J. M. Wang ◽  
C.-H. Jeong ◽  
N. Zimmerman ◽  
R. M. Healy ◽  
D. K. Wang ◽  
...  

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.


2017 ◽  
Vol 165 ◽  
pp. 155-168 ◽  
Author(s):  
Patricia Krecl ◽  
Christer Johansson ◽  
Admir Créso Targino ◽  
Johan Ström ◽  
Lars Burman

2015 ◽  
Vol 15 (19) ◽  
pp. 11011-11026 ◽  
Author(s):  
I. Ježek ◽  
T. Katrašnik ◽  
D. Westerdahl ◽  
G. Močnik

Abstract. The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote-sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years decreased by 60 and 47 % from those in use for 5–10 years, respectively; the median NOx and PN EFs of goods vehicles that were in use for less than 5 years decreased from those in use for 5–10 years by 52 and 67 %, respectively. Surprisingly, we found an increase of BC EFs in the newer goods vehicle fleet compared to the 5–10-year old one. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally, a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25 % of emitting diesel cars contributed 63, 47 and 61 % of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements and sophisticated post processing, individual vehicle EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving conditions.


2016 ◽  
Vol 124 ◽  
pp. 37-45 ◽  
Author(s):  
Jens Gallus ◽  
Ulf Kirchner ◽  
Rainer Vogt ◽  
Christoph Börensen ◽  
Thorsten Benter

2015 ◽  
Vol 15 (11) ◽  
pp. 15355-15396 ◽  
Author(s):  
I. Ježek ◽  
T. Katrašnik ◽  
D. Westerdahl ◽  
G. Močnik

Abstract. The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years, decreased by 60 and 47% from those in use for 5–10 years, respectively, the median NOx and PN EFs, of goods vehicles that were in use for less than five years, decreased from those in use for 5–10 years by 52 and 67%, respectively. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25% of emitting diesel cars contributed 63, 47 and 61% of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements with sophisticated post processing individual vehicles EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving conditions.


2014 ◽  
Vol 694 ◽  
pp. 13-18 ◽  
Author(s):  
Qian Yu ◽  
Tie Zhu Li ◽  
Yan Ming Ren ◽  
Na Zhu ◽  
Fang Qian

The purpose of this paper is to analyze the influence of passenger load on diesel bus emissions based on the real-world on-road emission data collected by the Portable Emission Measurement System (PEMS). It is also analyzed whether passenger load affect the accuracy of emission models based on VSP. The results indicate that the influence of passenger load on emission rates of CO2, CO, NOX and HC is various with different speed and acceleration ranges. As for the distance-based emission factors of CO2, CO, NOX and HC, per-passenger emission factors decrease with the rise of passenger load. In addition, it is found that the influence of passenger load can be omitted properly in the emission models of low and middle speed bins. But that can lead to an error reaching up to 49% if the influence of passenger load is neglected in the models of high speed bins.


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