Characterization identification and speciated emission inventory construction of anthropogenic volatile organic compounds (VOCs) in Beijing, China

Abstract

Volatile organic compounds (VOCs) significantly impact air quality and human health, garnering widespread attention. We conducted a comparative analysis of anthropogenic VOC emissions across different years, established a speciated VOC emission inventory for Beijing in 2020 and assessed the ozone formation potential (OFP). The VOC emissions showed a consistent downward trend, ranging from 10.19 × 10⁴ t to 28.36 × 10⁴ t in 2007–2020. The main sectors shifted from mobile sources (43.42%) and solvent utilization (26.35%) in 2007 to solvent utilization (55.99%) and mobile sources (24.00%) in 2020. The key contributing districts shifted from Fangshan (28.92%), Chaoyang (9.84%), and Daxing (7.33%) in 2013 to Chaoyang (14.29%), Haidian (11.42%), and Fangshan (10.33%) in 2020. The profile dataset encompasses 15 sectors and includes 117 VOC species, with an estimated total of 5.07 × 10⁴ t of VOC emissions in 2020, with alkanes, alkenes, alkyne, aromatics, halocarbons, and OVOCs accounting for 34.51%, 17.84%, 1.01%, 36.20%, 7.37%, and 3.07%, respectively. Significant differences were observed in the proportions of various VOC species across sectoral emissions. This dataset shows substantial deviations from the U.S. SPECIATE database, highlighting the significance of developing VOC source profiles. The uncertainties in VOC emission estimates primarily originate from variations in activity levels, emission factors and spatial distribution of emissions. Some sectors with high OFPs, like automobile manufacturing, barbecue and residential combustion are regarded as critical targets for emission control. Aromatics, alkenes, and OVOCs were identified as the major contributors to OFP, and controlling their emissions is essential for reducing ozone formation in Beijing.