title: On-road pollutant emission and fuel consumption characteristics of buses in Beijing.
abstract: On-road emission and fuel consumption (FC) levels for Euro III and IV buses fueled on diesel and compressed natural gas (CNG) were compared, and emission and FC characteristics of buses were analyzed based on approximately 28,700 groups of instantaneous data obtained in Beijing using a portable emissions measurement system (PEMS). The experimental results revealed that NOx and PM emissions from CNG buses were decreased by 72.0% and 82.3% respectively, compared with Euro IV diesel buses. Similarly, these emissions were reduced by 75.2% and 96.3% respectively, compared with Euro III diesel buses. In addition, CO2, CO, HC, NOx, PM emissions and FC of Euro IV diesel buses were reduced by 26.4%, 75.2%, 73.6%, 11.4%, 79.1%, and 26.0%, respectively, relative to Euro III diesel buses. The CO2, CO, HC, NOx, PM emissions and FC factors all decreased with bus speed increased, while increased as bus acceleration increased. At the same time, the emission/FC rates as well as the emission/FC factors exhibited a strong positive correlation with the vehicle specific power (VSP). They all were the lowest when VSP < 0, and then rapidly increased as VSP increased. Furthermore, both the emission/FC rates and emission/FC factors were the highest at accelerations, higher at cruise speeds, and the lowest at decelerations for non-idling buses. These results can provide a base reference to further estimate bus emission and FC inventories in Beijing.
authors.affiliation: National Lab of Auto Performance & Emission Test, Beijing Institute of Technology, Beijing 100081, China. wangaijuan9192@163.com
authors.forename: Aijuan
authors.initials: A
authors.lastname: Wang
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Ge
authors.forename: Jianwei
authors.initials: J
authors.lastname: Tan
authors.forename: Mingliang
authors.initials: M
authors.lastname: Fu
authors.forename: Asad Naeem
authors.initials: AN
authors.lastname: Shah
authors.forename: Yan
authors.initials: Y
authors.lastname: Ding
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.forename: Bin
authors.initials: B
authors.lastname: Liang
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D002681:China; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D005579:Fossil Fuels; D005742:Gasoline; D006801:Humans; D018986:Motor Vehicles; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D005579:Fossil Fuels; D005742:Gasoline; D001335:Vehicle Emissions