 |
| Titel |
Atmospheric chemical mechanims of the photooxidation of vinyl and allyl acetate initiated by Cl reactions |
| VerfasserIn |
María B. Blanco, Iustinian Bejan, Ian Barnes, Peter Wiesen, Mariano Teruel |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046625
|
|
|
|
|
|
| Zusammenfassung |
| Acetates have been widely released for decades into the atmosphere during their use in
industrial activities. Moreover, they are also emitted from natural sources (vegetation and
biomass combustion).(1) An additional potential source of these compounds is emission from
automobiles; a number of acetates, including vinyl acetate (VA) and allyl acetate (AA), have
been detected as products in the combustion of rape methyl esters used as fuel alternatives or
additives. (2)
The gas-phase removal processes of unsaturated esters include OH, NO3, Cl reactions. In
recent years the oxidations of volatile organic compounds (VOCs) by the highly reactive
chlorine atom has gained much attention mainly in the marine troposphere where significant
chlorine atom concentration may be present. (3)
In this work we report a product study for the reactions of Cl atoms with vinyl acetate
(CH3C(O)OCH=CH2) and allyl acetate (CH3C(O)OCH2CH=CH2).
The experiments were conducted using a 1080 liters quartz-glass environmental chamber
at (298±2) K in one atmosphere of synthetic air using in situ FTIR spectroscopy to monitor
the organics.
Product identification and quantification under atmospheric conditions were performed
for the first time for the reactions cited above.
The major products observed in the vinyl acetate with Cl reaction are formic acetic
anhydride and acetic acid together with formyl chloride as co-product and for the reaction of
allyl acetate with Cl atoms we observed acetoxyacetaldehyde, formic acetic anhydride and
acetic acid.
The results are used to postulate atmospheric chemical mechanisms which can be
incorporated into chemistry transport models to obtain estimations of the contributions of
emissions of such compounds to ozone and other photooxidant formation in the
troposphere.
This work is a part of an ongoing plan in our laboratory to study the kinetics and product
distribution of the unsaturated esters degradations and their impact on air quality.
(4-6)
References
(1) Graedel, T. E.; Hawkins, D. T.; Claxton, L. D. Atmospheric Chemical compounds:
Sources, Occurrence, and Bioassay; Academic Press: Orlando, FL, 1986.
(2) Ferrari, C., Ph.D., Universite´ Joseph Fourier-Grenoble 1, 1995.
(3) Spicer, C.W., Chapman, E.G., Finlayson-Pitts, B.J., Plastridge, R.A., Hubbe, J.M., Fast,
J.D., Berkowitz, C.M. Nature 394 (1998) 353.
(4) Blanco, M.B., Bejan, I., Barnes, I., Wiesen, P., Teruel, M.A. Environ. Sci. Pollut. Res. 16
(2009) 641.
(5) Blanco, M.B., Bejan, I., Barnes, I., Wiesen, P., Teruel, M.A. J. Phys. Chem. A. 113 (2009)
5958.
(6) Blanco, M.B., Bejan, I., Barnes, I., Wiesen, P., Teruel, M.A. Env. Sci. Technol. 44 (2010)
7031. |
|
|
|
|
|
|