Ozone Formation in Photochemical Oxidation of Organic Substances

A. J. Haagen-Smit; C. E. Bradley; M. M. Fox

doi:10.5254/1.3543469

Ozone Formation in Photochemical Oxidation of Organic Substances

Rubber Chemistry and Technology ◽

10.5254/1.3543469 ◽

1954 ◽

Vol 27 (1) ◽

pp. 192-200

Author(s):

A. J. Haagen-Smit ◽

C. E. Bradley ◽

M. M. Fox

Keyword(s):

Los Angeles ◽

Nitrogen Oxides ◽

Photochemical Oxidation ◽

Ozone Production ◽

Ozone Formation ◽

Peroxide Radical ◽

Radical Chain ◽

Low Concentrations ◽

Oxidation Of Alcohols ◽

Combustion Processes

Abstract The formation of ozone through photochemical oxidation of alcohols, aldehydes, ketones, acids, and hydrocarbons, such as are present in gasoline, in the presence of small quantities of nitrogen oxides has been demonstrated. Ozone production without the addition of nitrogen oxides has been observed in the photochemical oxidation of biacetyl, bibutyryl, pyruvic acid, and butyl nitrite. The ozone produced in these reactions was identified by chemical and physical methods. The ozone formation is attributed to a peroxide radical chain reaction. The release of large quantities of hydrocarbons to the air and the simultaneous presence of nitrogen oxides from combustion processes explains the relatively high ozone content, and consequent severe rubber cracking, in the Los Angeles area. These findings should be considered in planning rubber storage facilities. In view of the irritating properties of the products formed by this photochemical oxidation, both hydrocarbons and nitrogen oxides should be considered as potential irritants when they occur simultaneously in the air at low concentrations.

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Research Progress on Photocatalytic/Photoelectrocatalytic Oxidation of Nitrogen Oxides

Transactions of Tianjin University ◽

10.1007/s12209-021-00293-9 ◽

2021 ◽

Author(s):

Shuangjun Li ◽

Linglong Chen ◽

Zhong Ma ◽

Guisheng Li ◽

Dieqing Zhang

Keyword(s):

Nitrogen Oxides ◽

Photocatalytic Oxidation ◽

Research Progress ◽

Future Directions ◽

Inorganic Semiconductors ◽

Photoelectrocatalytic Oxidation ◽

Low Concentrations ◽

Photocatalytic System ◽

Metal Organic ◽

Oxidation Of No

AbstractThe emission of nitrogen oxides (NOx) increases year by year, causing serious problems to our livelihoods. The photocatalytic oxidation of NOx has attracted more attention recently because of its efficient removal of NOx, especially for low concentrations of NOx. In this review, the mechanism of the photocatalytic oxidation of NOx is described. Then, the recent progress on the development of photocatalysts is reviewed according to the categories of inorganic semiconductors, bismuth-based compounds, nitrogen carbide polymer, and metal organic frameworks (MOFs). In addition, the photoelectrocatalytic oxidation of NOx, a method involving the application of an external voltage on the photocatalytic system to further increase the removal efficiency of NOx, and its progress are summarized. Finally, we outline the remaining challenges and provide our perspectives on the future directions for the photocatalytic oxidation of NOx.

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Ozone formation from nitrogen oxides (NOx) in clean air. Comments

Environmental Science & Technology ◽

10.1021/es60120a017 ◽

1976 ◽

Vol 10 (9) ◽

pp. 934-936 ◽

Cited By ~ 4

Author(s):

B. Dimitriades ◽

M. C. Dodge ◽

J. J. Bufalini ◽

K. L. Demerjian ◽

A. P. Altshuller

Keyword(s):

Nitrogen Oxides ◽

Ozone Formation ◽

Clean Air

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Impact of a new condensed toluene mechanism on air quality model predictions in the US

Geoscientific Model Development Discussions ◽

10.5194/gmdd-3-2291-2010 ◽

2010 ◽

Vol 3 (4) ◽

pp. 2291-2314

Author(s):

G. Sarwar ◽

K. W. Appel ◽

A. G. Carlton ◽

R. Mathur ◽

K. Schere ◽

...

Keyword(s):

Air Quality ◽

Los Angeles ◽

Production Efficiency ◽

Sensitivity Study ◽

Chemical Mechanism ◽

Ozone Production ◽

Daily Maximum ◽

Air Quality Model ◽

Quality Model ◽

Mixing Ratios

Abstract. A new condensed toluene mechanism is incorporated into the Community Multiscale Air Quality Modeling system. Model simulations are performed using the CB05 chemical mechanism containing the existing (base) and the new toluene mechanism for the western and eastern US for a summer month. With current estimates of tropospheric emission burden, the new toluene mechanism increases monthly mean daily maximum 8-h ozone by 1.0–3.0 ppbv in Los Angeles, Portland, Seattle, Chicago, Cleveland, northeastern US, and Detroit compared to that with the base toluene chemistry. It reduces model mean bias for ozone at elevated observed ozone mixing ratios. While the new mechanism increases predicted ozone, it does not enhance ozone production efficiency. Sensitivity study suggests that it can further enhance ozone if elevated toluene emissions are present. While changes in total fine particulate mass are small, predictions of in-cloud SOA increase substantially.

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Improving spatial concentration estimates for nitrogen oxides using a hybrid meteorological dispersion/land use regression model in Los Angeles, CA and Seattle, WA

The Science of The Total Environment ◽

10.1016/j.scitotenv.2009.11.033 ◽

2010 ◽

Vol 408 (5) ◽

pp. 1120-1130 ◽

Cited By ~ 43

Author(s):

Darren Wilton ◽

Adam Szpiro ◽

Timothy Gould ◽

Timothy Larson

Keyword(s):

Land Use ◽

Los Angeles ◽

Nitrogen Oxides ◽

Regression Model ◽

Spatial Concentration ◽

Land Use Regression

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Ozone Photochemistry in New York City and Baltimore based on Aircraft Observations

10.5194/egusphere-egu21-6953 ◽

2021 ◽

Author(s):

Xinrong Ren ◽

Phillip Stratton ◽

Hannah Daley ◽

Russell Dickerson

Keyword(s):

New York ◽

New York City ◽

York City ◽

Production Efficiency ◽

Control Strategies ◽

Scientific Information ◽

Photochemical Oxidation ◽

Ozone Production ◽

Source Regions ◽

Aircraft Observations

Aircraft observations of ozone, ozone precursors, and meteorological parameters were made over the New York City (NYC) and Baltimore areas during ozone exceedance events in summer 2018-2020.&#160; Despite the continued reduction in anthropogenic emissions, ozone exceedance events still frequently occurred in the NYC area.&#160; Ozone production efficiency, defined as the ratio of the ozone production rate to the NOx oxidation rate, calculated using these observations,&#160; was about 14 ppb ozone produced per ppb NOx oxidized. This high ozone production efficiency likely contributes to the persistent ozone exceedance problem over the Long Island Sound and Connecticut coastal area, downwind of NYC under prevailing southwesterly winds.&#160; There is some evidence for a decreasing trend although COVID-19 restrictions had an impact on 2020 emissions.&#160; A box model, constrained by observations, was used to examine atmospheric photochemical oxidation processes.&#160; Ozone production rates and their sensitivity to nitrogen oxides (NOx) and volatile organic compounds (VOCs) were calculated based on the model results. In general ozone production is VOC sensitive near emission sources and NOx sensitive away from source regions. While the Baltimore area is predominantly in the NOx sensitive region, the NYC area is transitioning from VOC sensitive to NOx sensitive.&#160; Preliminary results show that controlling both NOx and VOCs reduces ozone production in the NYC area. Reducing VOCs can reduce ozone production in emission source regions and reducing NOx can reduce ozone production farther away from the source regions. The results from this work strengthen our understanding of ozone production and provide scientific information for emission control strategies to reduce air pollution in ozone non-attainment areas.

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Effect of isoprene emissions from major forests on ozone formation in the city of Shanghai, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-18527-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 18527-18556 ◽

Cited By ~ 1

Author(s):

F. Geng ◽

X. Tie ◽

A. Guenther ◽

G. Li ◽

J. Cao ◽

...

Keyword(s):

Ozone Production ◽

Ozone Formation ◽

Emission Model ◽

Peroxy Radicals ◽

Forest Regions ◽

High Concentrations ◽

The Impact ◽

The City ◽

Continuous Oxidation ◽

Ho2 Radical

Abstract. Ambient surface level concentrations of isoprene (C5H8) were measured in the major forest regions located south of Shanghai, China. Because there is a large coverage of broad-leaved trees in this region, high concentrations of isoprene were measured, ranging from 1 to 6 ppbv. A regional dynamical/chemical model (WRF-Chem) is applied for studying the effect of such high concentrations of isoprene on the ozone production in the city of Shanghai. The evaluation of the model shows that the calculated isoprene concentrations agree with the measured concentrations when the measured isoprene concentrations are lower than 3 ppb, but underestimate the measurements when the measured values are higher than 3 ppb. Isoprene was underestimated only at sampling sites near large bamboo plantations, a high isoprene source, indicating the need to include geospatially resolved bamboo distributions in the biogenic emission model. The assessment of the impact of isoprene on ozone formation suggests that the concentrations of peroxy radicals (RO2) are significantly enhanced due to the oxidation of isoprene, with a maximum of 30 ppt. However, the enhancement of RO2 is confined to the forested regions. Because the concentrations of NOx were low in the forest regions, the ozone production due to the oxidation of isoprene (C5H8 + OH →→ RO2 + NO →→ O3) is low (less than 2–3 ppb/h). The calculation further suggests that the oxidation of isoprene leads to the enhancement of carbonyls (such as formaldehyde and acetaldehyde) in the regions downwind of the forests, due to continuous oxidation of isoprene in the forest air. As a result, the concentrations of HO2 radical are enhanced, resulting from the photo-disassociation of formaldehyde and acetaldehyde. Because the enhancement of HO2 radical occurs in regions downwind of the forests, the enhancement of ozone production (6–8 ppb/h) is higher than in the forest region, causing by higher anthropogenic emissions of NOx. This study suggests that the biogenic emissions in the major forests to the south of Shanghai have important impacts on the levels of ozone in the city, mainly due to the carbonyls produced by the continuous oxidation of isoprene in the forest air.

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The Hydroxyl Radical and Its Role in Ozone Formation

The Mechanisms of Reactions Influencing Atmospheric Ozone ◽

10.1093/oso/9780190233020.003.0007 ◽

2015 ◽

Author(s):

Jack G. Calvert ◽

John J. Orlando ◽

William R. Stockwell ◽

Timothy J. Wallington

Keyword(s):

Water Molecule ◽

Organic Compounds ◽

Complex Mixture ◽

Peroxy Radical ◽

Molecular Formula ◽

Ozone Formation ◽

Alkoxy Radical ◽

Chain Reactions ◽

Low Concentrations ◽

Ho2 Radical

Although the HO radical is present in the sunlight-irradiated troposphere at very low concentrations, only about 106 molecules cm−3, it is the most important trace component in our atmosphere. It is a highly reactive transient species and is responsible for initiating the oxidation of the majority of organic compounds in the troposphere. It initiates the chain reactions that produce ozone. All the saturated, H-atom containing molecules react with HO through abstraction of an H atom. In the case of the simplest alkane, methane, reaction (1) leads to the formation of a water molecule and an alkyl (CH3) radical: . . . HO + CH4 → H2O + CH3 (1) . . . The CH3 radical released into the oxygen-rich atmosphere quickly adds O2 to give the methyl peroxy radical in reaction (2), which in NO-containing atmospheres can react to form NO2, and an alkoxy radical, CH3O, in reaction (3). In turn, this radical reacts with O2 to give an HO2 radical and a molecule of formaldehyde in (4). An HO radical can be regenerated as the HO2 molecule oxidizes NO to NO2 in (5), and the chain of events, reactions (1) through (5), leads to ozone generation through the photolysis of the NO2 molecule in reactions (6) and (7): . . . CH3 + O2 → CH3O2 (2) . . . . . . CH3O2 + NO → CH3O + NO2 (3) . . . . . . CH3O + O2 → HO2 + CH2O (4) . . . HO2 + NO → HO + NO2 (5) . . . . . . NO2 + hν → O + NO (6) . . . . . . O + O2 (+ M) → O3 (+ M) (7) . . . Methane is the least reactive of the alkanes with HO. Urban atmospheres contain a complex mixture of the more reactive larger alkanes (RH). The number of different possible geometric isomers and stereoisomers of the alkanes that can be formed by association of C and H atoms is astounding (Calvert et al., 2008). For example, there are more than a thousand structurally different molecules of molecular formula C12H26, more than a million C20H22, more than a billion of formula C25H52, and more than a trillion possible different isomers of molecular formula C31H64.

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Analysis of Nitrogen Oxides Formation in CH4/Air Laminar Premixed Flame

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1734 ◽

2013 ◽

Vol 750-752 ◽

pp. 1734-1737

Author(s):

Jun Xia Zhang ◽

Bing Biao Yang

Keyword(s):

Nitrogen Oxides ◽

Turbulent Diffusion ◽

Mass Fraction ◽

Burning Velocity ◽

Flame Temperature ◽

Premixed Flame ◽

Model Parameters ◽

Turbulent Diffusion Flame ◽

Chemical Reaction Kinetics ◽

Combustion Processes

Many combustion processes seriously pollute the environment because of producing nitrogen oxides emission, which abstracts wide attention from researchers. How to reduce nitrogen oxides emission is important to protect the environment. At the present work, a reduction mechanism based on a detailed chemical reaction kinetics mechanism, Gri_Mech3.0 was adopted to analyze nitrogen oxides formation in a CH4/air laminar premixed and turbulent diffusion flames, a two dimensional turbulent diffusion flame was simulated with the EDC model. Parameters were obtained, including flame temperature, burning velocity and mass fraction of nitrogen oxides. The results of laminar premixed flame show that nitrogen oxides emission mainly comes from the thermal and prompt NO mechanisms. A large amount of free radicals O, H and OH produced by combustion processes provide reactants for the reactions of nitrogen oxides formation. Mole fraction of nitrogen oxides increases with the increasing of both flame temperature and chemical equivalence ratios. By contrast, there is a lower mass fraction of nitrogen oxides formation for the fuel-lean flame.

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