title: On-board measurements of gaseous pollutant emission characteristics under real driving conditions from light-duty diesel vehicles in Chinese cities.
abstract: A total of 15 light-duty diesel vehicles (LDDVs) were tested with the goal of understanding the emission factors of real-world vehicles by conducting on-board emission measurements. The emission characteristics of hydrocarbons (HC) and nitrogen oxides (NOx) at different speeds, chemical species profiles and ozone formation potential (OFP) of volatile organic compounds (VOCs) emitted from diesel vehicles with different emission standards were analyzed. The results demonstrated that emission reductions of HC and NOx had been achieved as the control technology became more rigorous from Stage I to Stage IV. It was also found that the HC and NOx emissions and percentage of O2 dropped with the increase of speed, while the percentage of CO2 increased. The abundance of alkanes was significantly higher in diesel vehicle emissions, approximately accounting for 41.1%-45.2%, followed by aromatics and alkenes. The most abundant species were propene, ethane, n-decane, n-undecane, and n-dodecane. The maximum incremental reactivity (MIR) method was adopted to evaluate the contributions of individual VOCs to OFP. The results indicated that the largest contributors to O3 production were alkenes and aromatics, which accounted for 87.7%-91.5%. Propene, ethene, 1,2,4-trimethylbenzene, 1-butene, and 1,2,3-trimethylbenzene were the top five VOC species based on their OFP, and accounted for 54.0%-64.8% of the total OFP. The threshold dilution factor was applied to analyze the possibility of VOC stench pollution. The majority of stench components emitted from vehicle exhaust were aromatics, especially p-diethylbenzene, propylbenzene, m-ethyltoluene, and p-ethyltoluene.
authors: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China. Electronic address: wanggang70@emails.bjut.edu.cn.
authors: Gang
authors: G
authors: Wang
authors: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China; Collaborative Innovation Center of Electric Vehicles, Beijing 100081, China. Electronic address: chengsy@bjut.edu.cn.
authors: Shuiyuan
authors: S
authors: Cheng
authors: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China.
authors: Jianlei
authors: J
authors: Lang
authors: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China.
authors: Song
authors: S
authors: Li
authors: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China.
authors: Liang
authors: L
authors: Tian
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000473:Alkanes / Q000032:analysis; D000475:Alkenes / Q000032:analysis; D001555:Benzene Derivatives / Q000032:analysis; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D006838:Hydrocarbons / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis; D014050:Toluene / Q000031:analogs & derivatives / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000393:Air Pollutants; D000473:Alkanes; D000475:Alkenes; D001555:Benzene Derivatives; D006838:Hydrocarbons; D009589:Nitrogen Oxides; D001335:Vehicle Emissions; D055549:Volatile Organic Compounds; C007548:n-dodecane; C010313:pseudocumene; D014050:Toluene; C108160:4-ethyltoluene; C022884:undecane; C058602:1-butene
keywords: Emission factor; Hydrocarbon; Light-duty diesel vehicles; Nitrogen oxide; Ozone formation potential; Volatile organic compounds