||The emission of volatile organic compounds (VOCs) and odors from petrochemical industrial complex, including China Petroleum company (CPC),Renwu and Dazher petrochemical industrial parks, causes poor air quality of northern Kaohsiung. The removal efficiencies of elevated stacks and flares might play|
important roles on ambient air quality in metro Kaohsiung. Consequently, this study
applied a tethered balloon technology to measure the vertical profile of VOCs, and
ascertained their three dimensional dispersion in the atmosphere.
The vertical profile of VOCs in ambient atmosphere surrounding the
petrochemical industrial complex was measured during the intensive sampling periods
(September 17-18th and December 20-21st, 2009 and April 8-9th and July 7-8th, 2010).
Moreover, this study was designed to sample and analyze VOCs emitted from
elevated stacks and flares, and estimate their emission factors. Finally, the source
identification and ozone formation were further determined by principal component
analysis (PCA) and ozone formation potential (OFP).
This study found that some regions had relatively poorer air quality than other
regions surrounding the petrochemical industrial complex. Most sampling sites with
poor air quality were located at the downwind region of the petrochemical industrial
complex, particularly with the prevailing winds blown from the northwest. Moreover,
stratification phenomena were frequently observed at most sampling sites, indicating
that high-altitude VOCs pollution should be considered for ambient air quality.
This study revealed that the indicators of VOCs in northern Kaohsiung were
toluene, C2 (ethylene+acetylene+ethane), and acetone. Vertical sampling of VOCs
showed that the species of VOCs at the ground and high altitude were different,
suggesting that ambient air quality at high altitude might be affected by the emission
of VOCs from elevated stacks and flares at the petrochemical industrial complex.
Results obtained from PCA showed that the major sources of VOCs in the
ambient atmosphere of the petrochemical industrial complex were similar to the characteristics of VOCs emitted from the petrochemical industrial complex. The
characteristics of VOCs at high altitude had strong correlation with petrochemical
industry, indicating that the ambient air quality of northern Kaohsiung was highly
influenced by the emission of VOCs from high stacks and flares. In addition, major
VOCs for O3 formation potential at northern Kaohsiung were aromatics and vinyls,
with particular species of toluene and C2. Moreover, air pollution episodes resulting
from high O3 concentration was usually observed in early winter.
Flare sampling results indicated that major VOCs emitted from the ground flare
of CPC were alkanes and vinyls. The average removal efficiency of TVOCs was
98.2%. The average emission factor of VOCs was 0.0186 kg NMHC/kg flare gas. In
addition, stack sampling results indicated that the emission factors of crude oil
distillation process (P105), mixing process (P060), and rubber manufacturing process
(P408) were 0.105, 1.11, and 61.97 g/Kl, respectively. The emission factor of P105
was lower than AP-42, while that of P408 was higher than AP-42.