Emission Inventory of Vehicular NMVOCs in Beijing-Tianjin-Hebei (BTH) Region, China

The vehicular non-methane volatile organic compounds (NMVOCs) emissions were estimated in 2010 for Beijing-Tianjin-Hebei (BTH) region, China. The NMVOCs emission factors of passenger cars (PC), light duty vehicle (LDV), buses (BUS), heavy duty trucks (HDT) and motorcycles (MC) were calculated by the COPERT IV model. The total NMVOCs emissions were 78.9x10(3) t, 41.9x10(3) t and 139.8x10(3) t for Beijing, Tianjin and Hebei, respectively. PC was the main source category and vehicles with gasoline were the dominant contributors for NMVOCs emissions. Inventory for detailed NMVOCs species was also developed. Results showed that ethylene, toluene, benzene, isopentane, propene, ethane, m,p-xylene, 1,2,4-trimethylbenzene, 2-methylpentane and 1-Butene were the main species. Because of the important influences on ozone formation, the ozone formation potentials (OFP) of NMVOCs were further calculated. Alkene and benzenes, such as ethylene, propene, m,p-xylene, 1,2,4-trimethylbenzene, toluene, 1-Butene, m-ethyltoluene, o-Xylene, 2-Methyl-2-butene and 1,3,5-Trimetylbenzene, were the key species for ozone formation. The results can provide scientific support for mitigating vehicular emissions and improving air quality.