Chinese vehicle emissions characteristic testing with small sample size: Results and comparison

Abstract

Mobile emissions represent a main source of fine particulate matter (PM2.5) in China, however, few studies have tested the mobile source profiles of Chinese vehicles due to the high cost. In this study, the exhaust emissions of 21 Chinese vehicles, which were divided into five groups according to weight and fuel type, were sampled using the chassis dynamometerdilution tunnel method. PM2.5 mass, organic carbon (OC), elemental carbon (EC) and 190 compounds of organic matter were measured to compare emission characteristics with published mobile profiles. In this study, PM2.5 emission factors are higher for high mileage vehicles than new vehicles. (255 and 115 mg/km). Among all vehicle emissions, OC averaged 55.4±15.5% of PM2.5 mass while quantified organic carbon (QOC) averaged 4.5 ± 3.0% of PM2.5 mass. N-alkanes was the predominant species within QOC, averaging 57.0±22.1% of QOCby mass. Normal-aliphatic acids, which are products of catalysis, were observed in the highest concentrations in light-duty gasoline cars. Concentrations of polycyclic aromatic hydrocarbons with more than five rings (large PAHs) differed between gasoline and diesel vehicles, suggesting that large PAHs like benzo[ghi]perylene and coronene could be used to distinguish between fuel types. Hopanes and steranes made up a relatively small fraction of QOC compared with other species (1.1%-16.7% of the total QOC mass) but the relative concentrations of hopanes were similar among different vehicle types. The observed emission characteristics in this study are comparable with a US mobile source profiles published by Lough et al. (2007).

Source Apportionment of Fine Aerosol at an Urban Site of Beijing using a Chemical Mass Balance Model

“…species were in range of 0.8-1.2 in this study. The source profiles applied here were mostly from local studies in China to better represent the source characteristics, including straw burning (wheat, corn, rice straw burning) (Zhang et al, 2007b), wood burning (Wang et al, 2009), gasoline and diesel vehicles (including motorcycles, lightand heavy-duty gasoline and diesel vehicles) (Cai et al, 2017), industrial and residential coal combustion (including anthracite, sub-bituminite, bituminite, and brown coal) (Zhang et al, 2008), and cooking (Zhao et al, 2015), except vegetative detritus (Rogge et al, 1993;Wang et al, 2009). Fitting species should be stable during the transport from sources to receptor site and can represent the chemical characteristics of the sources (Wang et al, 2009 May to 24 th June 2017.…”

“…The source contributions to PM2.5 were calculated by multiplication of the fine OC source estimates from CMB by the ratios of fine OC to PM2.5 mass (Table S3), which were obtained from the same source profiles used for the OC apportionment by CMB (Zhang et al, 2007b;Wang et al, 2009;Cai et al, 2017;Zhang et al, 2008). For cooking, an OM/OC ratio of 1.4 was applied (Zhao et al, 2007).…”

“…CC BY 4.0 License. the CMB model are representative, we mainly selected those studies which had been based in China: straw burning (Zhang et al, 2007b), wood burning (Wang et al, 2009), gasoline and diesel vehicles (Cai et al, 2017), industrial and residential coal combustion (Zhang et al, 2008), and cooking (Zhao et al, 2015). Source contributions of organic carbon were examined and quantified applying the CMB model based on the source profiles mentioned above.…”

Source Apportionment of Carbonaceous Aerosols in Beijing with Radiocarbon and Organic Tracers: Insight into the Differences between Urban and Rural Sites

“…The CMB utilizes a linear least squares solution considering both uncertainties in source profiles and ambient measurements to ensure reliable fitting results. In order to better represent the source characteristics, the source profiles applied in this model were mostly from local studies in China (Cai et al, 2017;Wang et al, 2009;Zhang et al, 2007;Zhang et al, 2008b;Zhao et al, 2015), except vegetative detritus (Rogge et al, 1993;Wang et al, 2009). The detail of selecting organic marker species can be found in Yin et al (2010;.…”

Characteristics of the main primary source profiles of particulate matter across China: from 1987 to 2017

“…Vehicle emissions is appears to be the predominant source of ambient PM2.5 in urban areas in China (Cai et al, 2017b;Cui et al, 2016;Zhang et al, 2015). It is reported that the contribution of vehicle emissions to PM2.5 is in the range of 5% to 34% over China based on receptor models (Zhang et al, 2017b).…”