Generalized kinetic mechanism for photochemical smog

Hecht, T.; Seinfeld, John H.; Dodge, Marcia C.

doi:10.1021/es60089a004

Cited by 66 publications

(37 citation statements)

References 15 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the beginning, they were designed mainly to study the gas-phase reactions with ozone and the chemistry of NO x in the troposphere and the formation of aerosol from the gaseous pollutants [15][16][17]. Later research concentrated on the reactions of VOCs with OH radicals and their role in ozone formation and photochemical smog [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Rate Constants for the Reaction of OH Radicals with Hydrocarbons in a Smog Chamber at Low Atmospheric Temperatures

2018

View full text Add to dashboard Cite

Abstract:The photochemical reaction of OH radicals with the 17 hydrocarbons n-butane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, cyclooctane, 2,2-dimethylbutane, 2,2-dimethylpentane, 2,2-dimethylhexane, 2,2,4-trimethylpentane, 2,2,3,3-tetramethylbutane, benzene, toluene, ethylbenzene, p-xylene, and o-xylene was investigated at 288 and 248 K in a temperature controlled smog chamber. The rate constants were determined from relative rate calculations with toluene and n-pentane as reference compounds, respectively. The results from this work at 288 K show good agreement with previous literature data for the straight-chain hydrocarbons, as well as for cyclooctane, 2,2-dimethylbutane, 2,2,4-trimethylpentane, 2,2,3,3-tetramethylbutane, benzene, and toluene, indicating a convenient method to study the reaction of OH radicals with many hydrocarbons simultaneously. The data at 248 K (k in units of 10 −12 cm 3 s −1 ) for 2,2-dimethylpentane (2.97 ± 0.08), 2,2-dimethylhexane (4.30 ± 0.12), 2,2,4-trimethylpentane (3.20 ± 0.11), and ethylbenzene (7.51 ± 0.53) extend the available data range of experiments. Results from this work are useful to evaluate the atmospheric lifetime of the hydrocarbons and are essential for modeling the photochemical reactions of hydrocarbons in the real troposphere.

show abstract

Section: Introductionmentioning

confidence: 99%

Rate Constants for the Reaction of OH Radicals with Hydrocarbons in a Smog Chamber at Low Atmospheric Temperatures

2018

View full text Add to dashboard Cite

show abstract

“…Previous studies of PAN have related its occurrence to ~r imary pollutants such as nitrogen oxides and hydrocarbons (13)(14)(15). The formation of PAN in the polluted atmosphere is believed to be initiated by the photooxidation of hydrocarbons leading to aldehydes and, subsequently, peroxyacyl radicals.…”

Section: Introductionmentioning

confidence: 99%

The formation of ozone and peroxyacetyl nitrate (PAN) in the urban atmospheres of Alberta

Peake¹,

Sandhu²

1983

Can. J. Chem.

View full text Add to dashboard Cite

Atmospheric temperature inversions frequently trap pollutants in the urban atmospheres of Alberta leading to photochemical air pollution. Peroxyacetyl nitrate (PAN) was monitored, for the first time in Alberta, from November 1980 to August 1981 at the University of Calgary using electron capture gas chromatography. Measurements were made at one-half-hour intervals from July, 1981 to February, 1982 at a downtown location. Maximum PAN concentrations were recorded at the University and downtown sites on August 14 at 1400 h, 1981 and the values were 2.4 and 6.6 ppb, respectively. In each case the maximum PAN peak coincided with the afternoon peak in ozone concentrations, 79 ppb at the University and 59 ppb at the downtown site. Surprisingly, a high value of 2.3 ppb PAN was recorded at the University during January of 1981 giving rise to questions regarding the influence of low temperatures and solar radiation on the photochemical formation of PAN. Calculations employing a simple photochemical model for PAN and ozone formation have been carried out and comparisons made between the observed and the computed values.

show abstract

“…The paper described several potential limitations The first model produced ozone isopleths created by the Hecht, Seinfeld, Dodge mechanism in 1974. [16] This mechanism was the first to predict this ozone behaviour as a function of precursor levels.…”

Section: Emergence Of Photochemical Reaction Mechanisms and Computer mentioning

confidence: 99%

“…The 1974 Hecht, Seinfeld and Dodge [16] mechanism was one example of formulating a generalised mechanism directly. The mechanism was formulated based on generalised principles of VOC reactions and was tested and fitted with 13 different indoor smog chamber runs.…”

Section: Emergence Of Photochemical Reaction Mechanisms and Computer mentioning

confidence: 99%

Early history and rationale for outdoor chamber work at the University of North Carolina

2013

View full text Add to dashboard Cite

Environmental context. Imagine in 1968 having to tell the largest cities in the US that they would have to spend billions of dollars to reduce human exposure to a gas in their air that no one emitted and that no one knew for sure how it came to be there. This history recalls how scientists and policy makers met this challenge so that by 1985 effective programs were in place.Abstract. The University of North Carolina (UNC) outdoor chamber facility was established in 1972. The chamber produces reliable and interpretable results using ambient sunlight, temperature and weather, providing an effective physical model system for learning about atmospheric chemistry. This article recounts the 40-year history of the chamber facility, from the early days in understanding ozone-precursor relationship to the latest in studying gas and particulate toxicities on human lung cells. PrefaceLike other models, histories are subject to generalisations, distortions and deletions depending upon who is creating the history. We are sure that this history suffers from these operations. Please forgive us in advance if our recollections and mental constructs are somewhat at odds with your own. Perhaps we can have a 'conversation' about this sometime.

show abstract

Generalized kinetic mechanism for photochemical smog

Cited by 66 publications

References 15 publications

Rate Constants for the Reaction of OH Radicals with Hydrocarbons in a Smog Chamber at Low Atmospheric Temperatures

Rate Constants for the Reaction of OH Radicals with Hydrocarbons in a Smog Chamber at Low Atmospheric Temperatures

The formation of ozone and peroxyacetyl nitrate (PAN) in the urban atmospheres of Alberta

Early history and rationale for outdoor chamber work at the University of North Carolina

Contact Info

Product

Resources

About