The kinetics of the absorption of phosgene into water and aqueous solutions

Manogue, W.H.; Pigford, Robert L.

doi:10.1002/aic.690060329

Cited by 54 publications

(32 citation statements)

References 15 publications

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“…Kinetic and photochemical data suggest that COC12 is essentially unreactive in the troposphere; its reaction with OH is endothermic [DeMore et al, 1992], it is unreactive toward H20 vapor [Butler and Snelson, 1979] and its absorption cross section in the near UV and visible is quite small [Singh, 1976, Heydtmann, 1991. On the other hand, COC12 is known to dissolve in water and hydrolyze [Manogue and Pigford, 1960] and as a result is most likely removed from the troposphere by cloudwater and by deposition onto the ocean and other wet surfaces [Singh, 1976;Wine and Chameides, 1989]. Thus a simulation of the COC12 atmospheric cycle requires a quantitative treatment of its wet removal in clouds and to the ocean.…”

Section: Tropospheric Wet Removalmentioning

confidence: 99%

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃

Kindler¹,

Wine²,

Cunnold³

et al. 1995

J. Geophys. Res.

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A study of the tropospheric and stratospheric cycles of phosgene is carried out to determine its fate and ultimate role in controlling the ozone depletion potentials of its parent compounds (CCl4, C2Cl4, CH3CCl3, CHCl3, and C2HCl3). Tropospheric phosgene is produced from the OH‐initiated oxidation of C2Cl4, CH3CCl3, CHCl3, and C2HCl3. Simulations using a two‐dimensional model indicate that these processes produce about 90 pptv/yr of tropospheric phosgene with an average concentration of about 18 pptv, in reasonable agreement with observations. We estimate a residence time of about 70 days for tropospheric phosgene, with the vast majority being removed by hydrolysis in cloudwater. Only about 0.4% of the phosgene produced in the troposphere avoids wet removal and is transported to the stratosphere, where its chlorine can be released to participate in the catalytic destruction of ozone. Stratospheric phosgene is produced from the photochemical degradation of CCl4, C2Cl4, CHCl3, and CH3CCl3 and is removed by photolysis and downward transport to the troposphere. Model calculations, in good agreement with observations, indicate that these processes produce a peak stratospheric concentration of about 25–30 pptv at an altitude of about 25 km. In contrast to tropospheric phosgene, stratospheric phosgene is found to have a lifetime against photochemical removal of the order of years. As a result, we find that a significant portion of the phosgene that is produced in the stratosphere is ultimately returned to the troposphere, where it is rapidly removed by clouds. This phenomenon effectively decreases the amount of reactive chlorine injected into the stratosphere and available for ozone depletion from phosgene's parent compounds; we estimate approximate decreases of 14, 3, 15, and 25% for the stratospheric chlorine loadings of CCl4, CH3CCl3, C2Cl4, and CHCl3, respectively. A similar phenomenon due to the downward transport of stratospheric COFCl produced from CFC‐11 is estimated to cause a 7% decrease in the amount of reactive chlorine injected into the stratosphere from this compound. Our results are potentially sensitive to a variety of parameters, most notably the rate of reaction of phosgene with sulfate aerosols. However, on the basis of the observed vertical distribution of COCl2, we estimate that the reaction of COCl2 with sulfate aerosol most likely has a γ< 5×10−5 and, as a result, has a negligible impact on the stratospheric chlorine loadings of the phosgene parent compounds.

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Section: Tropospheric Wet Removalmentioning

confidence: 99%

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃

Kindler¹,

Wine²,

Cunnold³

et al. 1995

J. Geophys. Res.

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“…0 : pulse radiolysis. CCl,O; plus 1approach: A ; pulse radiolysis, 'CCI, plus 'OH approach; 0: laminar jet method [5].…”

mentioning

confidence: 99%

A Kinetic Study of the Hydrolysis of Phosgene in Aqueous Solution by Pulse Radiolysis

Mertens

Sonntag

Lind

et al. 1994

Angew. Chem. Int. Ed. Engl.

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COMMUNICATIONS i J 1 I I 10349 rellections]. wR2 = 0.141 ; Enraf-NoniusCAD4 four-circle diffractometer: 173 K : Cu,,, radiation: 11 =l.OOmm-'; 2.85 < 0 < 69 : empirical ahsorption correction (DIFABS [18]); structure solution with SHELX-86 [16], refinement with SHELXL-93 [17]: the torsion angles were refined for all the methyl groups. the remaining H atoms were calculated in ideal positions and treated iis "riding" in further refinements. 1 crystallizes with two formula units per unit cell in the triclinic space group PT. The asymmetric unit contains two cations. one anion. and one and a half molecules of benzene. Further details of thc ci-)\kil structiii-e investigation iimy be obtained from the Fachinformationszentrum Karlsruhe. D-76344 Eggenstein-Leopoldshafen (FRG) on quoting the depository number CSD-57976.

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“…The results from Mirabel's group are derived from an analysis of droplet train uptake data that is essentially the same as that used in the Aerodyne Research, Inc./Boston College effort. Additional literature values of k hyd and H for CC1 2 0 (which has not yet been studied by the Mirabel group) are also listea (9)(10)(11)(12). The uptake parameters derived from the experimental results of Mirabel and coworkers (3,4) are significanUy larger than those deduced from the Aerodyne Research/ Boston College data (6,7).…”

Section: Halocarbonyl Uptake Resultsmentioning

confidence: 85%

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Kolb

Worsnop

Zahniser

et al. 1997

ACS Symposium Series

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Alternative halocarbons designed to substitute for chlorofluorocarbons and halons banned by the Montreal Protocol are designed to undergo oxidative degradation in the troposphere.Intermediate partially oxygenated products from currently used alternatives include carbonyl halides, haloacetyl halides and haloacetic acids. These intermediates are expected to undergo heterogeneous reactions with aqueous cloud droplets and surface waters. The chemical and physical parameters which govern the heterogeneous uptake of a range of these species by liquid water have been measured in our laboratories using droplet train/flow tube and/or bubble column techniques. The results of these experiments will be presented and compared with available results from other laboratories. Their impact on our ability to predict the atmospheric fate of halocarbon oxidation intermediates will be discussed. Atmospheric Fate of Alternative Halocarbon Oxidation ProductsAlternative halocarbons planned as substitutes for chlorofluorocarbons and halons banned by the Montreal Protocol are designed to undergo oxidative degradation in the troposphere. Intermediate partially oxygenated products from currently used or proposed alternatives include carbonyl halides, haloacetyl halides and haloacetic acids. A wide variety of atmospheric processes could participate in the removal of relatively stable degradation intermediates, including: transport to the stratosphere followed by photolysis, uptake by both tropospheric and stratospheric aerosols, uptake by cloud droplets, rainout (wet deposition), and dry deposition to vegetation, soil and dew surfaces, and to the oceans. However, recent model analyses indicate that cloud droplet and ocean uptake are the most likely removal rate determining processes. The physicochemical processes which are important in determining the rate of trace atmospheric gas uptake by liquid surfaces include gas phase diffusion, mass accommodation, solvation (Henry's law solubility), liquid phase diffusion and liquid phase reaction. The most effective removal paths and their associated physicochemical parameters are displayed in Table I. Key parameters affecting atmospheric removal rates are the mass accommodation coefficient, a, the Henry's law constant, H, and the first order hydrolysis reaction rate coefficient, k hyd .

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The kinetics of the absorption of phosgene into water and aqueous solutions

Cited by 54 publications

References 15 publications

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃

A Kinetic Study of the Hydrolysis of Phosgene in Aqueous Solution by Pulse Radiolysis

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

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The kinetics of the absorption of phosgene into water and aqueous solutions

Cited by 54 publications

References 15 publications

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl4, C2Cl4, C2HCl3, CH3CCl3, and CHCl3

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl4, C2Cl4, C2HCl3, CH3CCl3, and CHCl3

A Kinetic Study of the Hydrolysis of Phosgene in Aqueous Solution by Pulse Radiolysis

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

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Product

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The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃

The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl₄, C₂Cl₄, C₂HCl₃, CH₃CCl₃, and CHCl₃