Emissions of Oxygenated Volatile Organic Compounds and Their Roles in Ozone Formation in Beijing

Oxygenated volatile organic compound (OVOC) emissions play a critical role in tropospheric ozone (O3) formation. This paper aims to establish an emission inventory and source profile database for OVOCs in Beijing, utilizing revised and reconstructed data from field measurements and existing literature. The study also assesses their potential impact on the O3 base on the ozone formation potential (OFP). Results indicate that OVOC emissions in Beijing predominantly originate from natural and residential sources, encompassing commercial solvent usage, cooking, residential combustion, construction adhesives, and construction coatings. OVOCs contributed 5.6% to OFP, which is significantly less than their emission contribution of 20.1%. Major OFP contributors include plant sources (26.2%), commercial solvent use (21.0%), cooking (20.5%), and construction adhesives (8.4%). The primary OVOC species contributing to OFP for OVOCs are acetaldehyde, methanol, hexanal, ethanol, and acetone, collectively contributing 59.0% of the total OFP. Natural sources exhibit significant seasonal variability, particularly in summer when plant emissions peak, constituting 78.9% of annual emissions and significantly impacting summer ozone pollution (OFP of 13,954 t). Conversely, emissions from other OVOC sources remain relatively stable year-round. Thus, strategies to mitigate summer ozone pollution in Beijing should prioritize plant sources while comprehensively addressing residential sources in other seasons. District-specific annual OVOC emissions are from Fangshan (3967 t), Changping (3958 t), Daxing (3853 t), and Chaoyang (3616 t), which reflect year-round forested areas in these regions and high populations.