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An assessment of potential impact of alternative fluorocarbons on tropospheric ozone
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Niki, Hiromi |
| Copyright Year | 1990 |
| Description | While the chlorofuorocarbons (CFCs) such as CFC-11 (CFCl3) and CFC-12 (CF2Cl2) are chemically inert in the troposphere, the hydrogen-containing halocarbons being considered as their replacements can, to a large extent, be removed in the troposphere by the HO radical. These alternative halocarbons include the hydrochlorofluorocarbons (HCFCs) 123 (CF3CHCl2), 141b (CFCl2CH3), 142b (CF2ClCH3), 22 (CHF2Cl), and 124 (CF3CHFCl) and the hydrofluorocarbons (HCFs) 134a (CF3CH2F), 152a (CHF2CH3) and 125 (CF3CHF2). Listed are the rate constants (k) for the HO radical reaction of these compounds and their estimated chemical lifetimes in the troposphere. In this table, values of the lifetimes of these selected HCFCs and HCFs are seen to vary by more than a factor of more than ten ranging from 1.6 years for HFC 152a and HCFC 125 to as long as 28 years for HFC 125. Clearly, from the standpoint of avoiding or minimizing impact on stratospheric O3, those halocarbons with short tropospheric lifetimes are the desirable alternates. However, potential environmental consequences of their degradation in the troposphere should be assessed and taken into account in the selection process. |
| File Size | 924799 |
| Page Count | 24 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19920006230 |
| Archival Resource Key | ark:/13960/t0gv0h96w |
| Language | English |
| Publisher Date | 1990-01-01 |
| Access Restriction | Open |
| Subject Keyword | Environment Pollution Chlorofluorocarbons Ozone Depletion Troposphere Stratosphere Constants Ozone Fluorocarbons Radicals Degradation Fluorohydrocarbons Rates Per Time Atmospheric Composition Reaction Kinetics Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
