Fence Line Monitoring of Petroleum Refining Plants in Korea: UV-DOAS Analysis of SO2, NO2, and Benzene Emissions for Comprehensive Management

Increasing public interest in air pollutants driven by climate change and high concentrations of particulate matter (PM) has highlighted the importance of managing pollutants, such as SO₂, NO₂, and benzene. These compounds are known precursors of secondary PM that affect the climate and human health, with benzene being particularly carcinogenic. Benzene is a volatile organic compound (VOC) that can persist in the atmosphere for approximately 9.4 days, potentially traveling long distances and contributing to the generation of secondary organic aerosols (SOAs) through photochemical reactions, leading to elevated fine dust concentrations. To comprehensively manage emissions, leaks, and point sources, a fence line monitoring study was conducted at petroleum refining industrial complexes in Daesan-eup, Chungcheongnam-do, and Yeosu-si, Jeollanam-do in Korea. Ultraviolet Differential Optical Absorption Spectroscopy (UV-DOAS) technology was used to confirm measurement reliability and monitor emissions. High SO₂ concentrations emitted in a specific direction were identified at the Yeosu-si, and further investigation identified the flare stack of a suspected plant as the emission source. Fence line monitoring was effective in identifying and addressing unknown high-concentration emission sources and devising measures to manage fugitive emissions and leaks.