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Abstract: This study made a field VOCs (volatile organic compounds) measurement for a petroleum refinery in Beijing by determining 56 PAMS VOCs, which are demanded for photochemical assessment in US, and obtained the characteristics of VOCs emitted from the whole refinery and from its inner main devices. During the monitoring period, this refinery brought about an average increase of 61 ppbv in the ambient TVOCs (sum of the PAMS VOCs) at the refinery surrounding area, while the background of TVOCs there was only 10–30 ppbv. In chemical profile, the VOCs emitted from the whole refinery was characteristic by isobutane (8.7%), n-butane (7.9%), isopentane (6.3%), n-pentane (4.9%%), n-hexane (7.6%), C6 branched alkanes (6.0%), propene (12.7%), 1-butene (4.1%), benzene (7.8%), and toluene (5.9%). On the other hand, the measurement for the inner 5 devices, catalytic cracking units (CCU2 and CCU3), catalytic reforming unit (CRU), tank farm (TF), and wastewater treatment(WT), revealed the higher level of VOCs pollutions (about several hundred ppbv of TVOCs), and the individual differences in VOCs chemical profiles. Based on the measured speciated VOCs data at the surrounding downwind area, PMF receptor model was applied to identify the VOCs sources in the refinery. Then, coupling with the VOCs chemical profiles measured at the device areas, we concluded that CCU1/3 contributes to 25.9% of the TVOCs at the surrounding downwind area by volume, followed by CCU2 (24.7%), CRU (18.9%), TF (18.3%) and WT (12.0%), which was accordant with the research of US EPA (2008). Finally, ozone formation potentials of the 5 devices were also calculated by MIR technique, which showed that catalytic cracking units, accounting for about 55.6% to photochemical ozone formation, should be given the consideration of VOCs control firstly. [Copyright &y& Elsevier]

In this study, a new approach combining the environment monitoring, model simulation and source apportionment methods was proposed to investigate the impact of vehicular emissions on the PM2.5 pollution. The method can identify the contributions of various emission sources to both the primary and secondary particles. A case application was conducted in Beijing, China. An intensive monitoring covering the period of December 2010 to January 2012 was conducted to obtain the detailed chemical components proportions in the total PM2.5. The vehicular emission contributions (VECs) to primary organic aerosols (POA), element carbon (EC), SO2, NO X , NH3, elements and VOC were estimated based on the MM5-CMAQ simulation, factor analysis and references investigation. The VECs to different components and to the total PM2.5 were then calculated. Results showed that there was no clear difference in the total VECs of different seasons. The annual average contribution ratio was approximately 22.5 ± 3.5%. Among all the chemical species, nitrate and SOA accounted for the highest contribution percentages. In addition, the influence of road dust on the PM2.5 pollution was also simulated using the MM5-CMAQ modeling system. It is indicated that the road dust contributed approximately 4.9 ± 1.3% of the total PM2.5 on an annual average. Considering both the contributions from motor vehicles and road dust emissions, the annual average direct contributions from road transport to the PM2.5 in Beijing was approximately 27.4 ± 4.8%. [ABSTRACT FROM AUTHOR]