Atmospheric lifetime of CHF sub 2 Br, a proposed substitute for halons
Journal Article
·
· Science (Washington, D.C.); (United States)
- National Oceanic and Atmospheric Administration, Boulder, CO (United States) Univ. of Colorado, Boulder (United States)
The rate coefficients, k{sub 1}, for the reaction of OH with CHF{sub 2}Br have been measured using pulsed photolysis and discharge flow techniques at temperatures (T) between 233 and 432 K to be k{sub 1} = (7.4 {plus minus} 1.6) {times} 10{sup {minus}13} exp({minus}(1,300 {plus minus} 100)/T) cubic centimeters per molecule per second. The ultraviolet absorption cross sections, {sigma}, of this molecule between 190 and 280 nanometers were measured at 296 K. The k{sub 1} and {sigma} values were used in a one-dimensional model to obtain an atmospheric lifetime of approximately 7 years for CHF{sub 2}Br. This lifetime is shorter by approximately factors of 10 and 2 than those for CF{sub 3}Br and CF{sub 2}ClBr, respectively. The ozone depletion potentials of the three compounds will reflect these lifetimes.
- OSTI ID:
- 6102710
- Journal Information:
- Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 252:5006; ISSN SCIEA; ISSN 0036-8075
- Country of Publication:
- United States
- Language:
- English
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