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Titel |
Kinetic investigation of the unsaturated nitriles degradation initiated by OH reaction in atmospheric conditions |
VerfasserIn |
Juan P. Colomer, María B. Blanco, Alicia B. Peñéñory, Ian Barnes, Peter Wiesen, Mariano A. Teruel |
Konferenz |
EGU General Assembly 2011
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 13 (2011) |
Datensatznummer |
250058201
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Zusammenfassung |
Unsaturated nitriles are usually released from industries and also widely used in the
production of plastics, nitrile rubbers, nitrile barrier resins, adiponitrile and acrylamide. Upon
its formation this nitrile may decompose and produce poisonous gases like hydrogen cyanide.
(1)
Other sources of unsaturated nitriles are minute traces in food packaging and accidental
chemical spills. There are believed to be no significant natural sources. (2)
The release of these volatile organic compounds (VOCs) into the atmosphere is likely to
contribute to the formation of ozone and other components of photochemical smog found in
urban areas through their reactions with OH and NO3 radicals as well as with O3 and Cl
atoms. In this work, we report rate coefficients for the reactions of OH radicals with
(E)-3-pentenenitrile (k1) and 4-pentenenitrile (k2).
OH + CH3CH=CHCH2CN - Products (k1)
OH + CH2=CHCH2CH2CN - Products (k2)
Relative rate constants were measured by comparing the OH radical reaction rate with
the pentenenitriles to that butyl acrylate, 1,3-butadiene and isobutene used as the
reference compounds. All the experiments were performed in synthetic air (296 ±
3 K and 1010 mbar) in 1080 L quartz-glass photoreactor equipped with a White
type multiple reflection mirror system operated at a total optical path length of
(484.7 ± 0.8) m coupled to an NEXUS FTIR spectrometer with a MCT detector.
(3)
To the best of our knowledge this is the first experimental determination of the rate constants
for these reactions.
Kinetics data are used to estimate the tropospheric lifetimes for the unsaturated nitriles
studied. Lifetimes of few hours were obtained for the OH-initiated degradation of the
pentenenitriles indicating that these compounds will be oxidized close their anthropogenic
sources indicating their importance in the photochemical smog production.
Referencces
(1) Anderson, R.A., Watson A.A, Harland, W.A. Medicine Science Law. 21(4) (1981)
288.
(2) http://www.environment-agency.gov.uk.
(3) Barnes, I., Becker, K.H., Mihalopoulos, N. J. Atmos. Chem. 18 (1994) 267. |
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