Ozone Formation Potential and Priority Species of VOCs in an Industrial Park

Abstract

Ground-level ozone (O3) pollution is a serious problem in major cities in China. The control of its precursors, volatile organic compounds (VOCs), is a key to limiting ozone production. The ozone formation potential of VOCs in an industrial park in Tianjin was studied by collecting gas samples at the factory boundaries of six representative enterprises. The PTR-TOF-MS was used to analyze VOCs quantitatively. The VOCs/NOx ratio was used to determine the control strategies. The priority VOCs were selected based on the entropy method. Our results indicated that, the ozone formation potential concentration of enterprise F was the highest with the concentration of 0.4233 mg·m-3 using the propylene-equivalent concentration (PEC) scale; the highest concentration was obtained at enterprise C with 1.5733 mg·m-3 using maximum incremental reactivity(MIR) scale. The result of PEC scale is closer to the O3 concentration, which is applicable to the study of ozone generation in this industrial park. Ozone production is sensitive to both VOCs and NOx in this industrial park, joint control should be considered. Alkanes contributed most to ozone formation, followed by alkenes & alkynes, alcohols, and aromatics. The prior VOC species that need to be controlled include n-heptane and its isomers, n-nonane, n-octane and its isomers, undecane, pentane, n-decane, and methanol.