Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong
Vehicle emissions of volatile organic compounds (VOCs) were determined at the Shing Mun Tunnel, Hong Kong in summer and winter of 2003. One hundred and ten VOCs were quantified in this study. The average concentration of the total measured VOCs at the inlet and outlet of the tunnel were 81 250 pptv...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2009-10-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/9/7491/2009/acp-9-7491-2009.pdf |
| Summary: | Vehicle emissions of volatile organic compounds (VOCs) were determined at
the Shing Mun Tunnel, Hong Kong in summer and winter of 2003. One hundred
and ten VOCs were quantified in this study. The average concentration of the
total measured VOCs at the inlet and outlet of the tunnel were 81 250 pptv
and 117 850 pptv, respectively. Among the 110 compounds, ethene, ethyne and
toluene were the most abundant species in the tunnel. The total measured VOC
emission factors ranged from 67 mg veh<sup>−1</sup> km<sup>−1</sup> to
148 mg veh<sup>−1</sup> km<sup>−1</sup>,
with an average of 115 mg veh<sup>−1</sup> km<sup>−1</sup>. The five most
abundant VOCs observed in the tunnel were, in decreasing order, ethene,
toluene, <i>n</i>-butane, propane and <i>i</i>-pentane. These five most abundant species
contributed over 38% of the total measured VOCs emitted. The high propane
and <i>n</i>-butane emissions were found to be associated with liquefied petroleum
gas (LPG)-fueled taxis. Fair correlations were observed between marker
species (ethene, <i>i</i>-pentane, <i>n</i>-nonane, and benzene, toluene, ethylbenzene and
xylenes – BTEX) with fractions of gasoline-fueled or diesel-fueled vehicles.
Moreover, ethene, ethyne, and propene are the key species that were abundant
in the tunnel but not in gasoline vapors or LPG. The ozone formation
potential from the VOCs in Hong Kong was evaluated by the maximum increment
reactivity (MIR). It was found to be 568 mg of ozone per vehicle per
kilometer traveled. Among them, ethene, propene and toluene contribute most
to the ozone-formation reactivity. |
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| ISSN: | 1680-7316 1680-7324 |