Thermal Decomposition Of Peroxyacetyl Nitrate Research Articles

Underappreciated Emission Spikes From Power Plants During Heatwaves Observed From Space: Case Studies in India and China

AbstractThe frequency, intensity, and duration of extreme heatwaves are projected to increase in the global context of climate change. However, evidence of how anthropogenic emissions respond to heatwaves and further impact air quality remains elusive. Here, we use satellite remote sensing measurements alongside chemical transport model simulations to reveal abrupt variations in primary and secondary air pollutants introduced by extreme heatwaves. We highlight evidence from China and India, where satellite sulfur dioxide (SO2) and nitrogen dioxide (NO2) columns over thermal power plants enhance consistently responding to heatwaves. We attribute such spiked emissions to soaring electricity use and demonstrate that bottom‐up inventories underestimate the emissions from the power sector by 34.9% for the selected case. Elevated emissions facilitate fine particulate matter (PM2.5) and ozone (O3) formation over thermal power plants in an inhomogeneous manner, due to the combined effect of atmospheric oxidizing capacity, thermal decomposition of peroxyacetyl nitrate, planetary boundary layer rise, and air stagnation. Our results underscore the emerging challenge of pollution control attributable to the increasing climate penalty and the necessity of targeted control strategies and alternative energy sources during heatwaves.

Influence of thermal decomposition and regional transport on atmospheric peroxyacetyl nitrate (PAN) observed in a megacity in southern China

Peroxyacetyl nitrate (PAN) is a typical secondary product of photochemical smog and is widely considered an indicator when evaluating the severity of photochemical pollution, but there have been few quantitative studies on the thermal decomposition of ambient PAN in southern China. In this study, online sampling of PAN and ozone (O3) was conducted from August to November 2020, which is the most severe photochemical pollution period of the year, in Shenzhen, a megacity in southern China. During the sampling period, two photochemical pollution periods occurred in August (EP1) and October (EP2). The mean O3 concentrations during EP1 and EP2 were very close, 36.3 and 36.9 ppb, respectively, while PAN concentrations were very different (0.66 and 1.06 ppb, respectively). The diurnal variation showed that the PAN formation rate in the initial stage of photochemical reactions (9:00–11:00) during EP1 was significantly faster than that during EP2, while there was significant consumption at noon and almost complete decomposition at night in EP1. Calculating the thermal decomposition of PAN (TPAN), we found that the average concentration of TPAN in EP1 was 8.47 ppb, approximately 9 times that in EP2 (0.94 ppb), which significantly reduced the concentration of PAN in EP1. This indicates that when using PAN as an indicator of photochemical reaction activity, the consumption of PAN due to thermal decomposition must be considered. In addition, we found that regional transport may significantly contribute to the formation of PAN by increasing the concentration of precursor VOCs, although the lifetime of PAN was only a few hours due to a large amount of thermal decomposition.

Interferences in photolytic NO<sub>2</sub> measurements: explanation for an apparent missing oxidant?

Abstract. Measurement of NO2 at low concentrations (tens of ppts) is non-trivial. A variety of techniques exist, with the conversion of NO2 into NO followed by chemiluminescent detection of NO being prevalent. Historically this conversion has used a catalytic approach (molybdenum); however, this has been plagued with interferences. More recently, photolytic conversion based on UV-LED irradiation of a reaction cell has been used. Although this appears to be robust there have been a range of observations in low-NOx environments which have measured higher NO2 concentrations than might be expected from steady-state analysis of simultaneously measured NO, O3, jNO2, etc. A range of explanations exist in the literature, most of which focus on an unknown and unmeasured “compound X” that is able to convert NO to NO2 selectively. Here we explore in the laboratory the interference on the photolytic NO2 measurements from the thermal decomposition of peroxyacetyl nitrate (PAN) within the photolysis cell. We find that approximately 5 % of the PAN decomposes within the instrument, providing a potentially significant interference. We parameterize the decomposition in terms of the temperature of the light source, the ambient temperature, and a mixing timescale ( ∼ 0.4 s for our instrument) and expand the parametric analysis to other atmospheric compounds that decompose readily to NO2 (HO2NO2, N2O5, CH3O2NO2, IONO2, BrONO2, higher PANs). We apply these parameters to the output of a global atmospheric model (GEOS-Chem) to investigate the global impact of this interference on (1) the NO2 measurements and (2) the NO2 : NO ratio, i.e. the Leighton relationship. We find that there are significant interferences in cold regions with low NOx concentrations such as the Antarctic, the remote Southern Hemisphere, and the upper troposphere. Although this interference is likely instrument-specific, the thermal decomposition to NO2 within the instrument's photolysis cell could give an at least partial explanation for the anomalously high NO2 that has been reported in remote regions. The interference can be minimized by better instrument characterization, coupled to instrumental designs which reduce the heating within the cell, thus simplifying interpretation of data from remote locations.

ChemInform Abstract: Thermal Decomposition of Peroxyacetyl Nitrate and Reactions of Acetyl Peroxy Radicals with NO and NO2 Over the Temperature Range 283-313 K

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The seasonal cycle of peroxyacetyl nitrate (PAN) in the European Arctic

Measurements of peroxyacetyl nitrate (PAN) over a 3-yr period at the Zeppelin mountain near Ny-Ålesund, Svalbard show a distinct annual cycle with a spring maximum of about 400 pmol mol −1, and a summer minimum of 80 pmol mol −1. In this paper the measurement technique is shown together with a detailed error discussion. PAN at this high latitude location is co-transported with ozone. Thermal decomposition of PAN in the high Arctic troposphere may occur mostly during summer. During spring it is too small for PAN to have a sizeable local effect on the observed spring time ozone maximum.

Estimation of tropospheric ozone production using concentrations of hydrocarbons and NO x, and a comprehensive hydrocarbon reactivity parameter

We have developed a photochemical model for calculating the ozone concentration in a near-stationary air mass in the lower troposphere using data on chemical composition from August 1993, in the Village of Hastings, Ontario. The calculated concentration of ozone as afunction of time was in good agreement with experiment for these data sets, except during incursions of air masses of different origin. Consideration of the mechanism of ozone formation allowed the ozone-forming potential of all hydrocarbons to be considered as a group, rather than using empirical values of ozone molecules formed per substrate molecule destroyed for each individual hydrocarbon. Use of the model predictively indicated that changes in NO x concentration and light intensity had much greater impact upon the calculated ozone concentration than changes in relative humidity and hydrocarbon concentrations. The dependence of ozone concentration upon temperature was almost entirely due to thermal decomposition of peroxyacetyl nitrate (PAN), which adds to the reservoir of NO 2 on hot days.

Reactive nitrogen and its correlation with O3 and CO over the Pacific in winter and early spring

Measurements of NO, NOy, O3, and CO were made during NASA's Global Tropospheric Experiment/Pacific Exploratory Mission‐West B (GTE/PEM‐West B) carried out over the western Pacific in February and March 1994. NOx was calculated from NO using a photostationary state model ((NOx)mc). Correlations between these species are presented, and some insights into the sources of NOx and NOy are described. The boundaries between the lower, middle, and upper troposphere have been defined at potential temperatures of 311 K and 328 K, which correspond to the geometric altitudes of about 5 and 9 km at 30°N. Enhancements in the mixing ratios of NOy and CO were observed in the lower and middle troposphere. A positive correlation was found between these two species suggesting that the high NOy values were due to anthropogenic emissions over the continental surface. On the other hand, O3 increased little with increase in CO. As a result, NOy/O3 ratios were higher in air more influenced by pollution. NOy values in 55 and 28% of the air masses sampled in the lower and middle troposphere, respectively, were higher than the clean free tropospheric NOy‐O3 range when O3 values simultaneously observed were used. High (NOx)mc/NOy ratios between 0.15 and 0.3 were found in the boundary layer with relatively low mixing ratios of CO and NOy during the three flights. These air masses were transported from a higher altitude (∼5 km) and a higher latitude (∼50°N) within a few days. The peroxyacetyl nitrate (PAN)/NOy ratios were generally high (∼0.4) in these air masses, and the thermal decomposition of PAN was a probable source of NOx. In the middle troposphere the (NOx)mc mixing ratio did not generally increase with NOy or CO, suggesting that the transport of air masses affected by anthropogenic emissions did not increase the NOx level significantly. In the upper troposphere, very minor effects from the continental surface sources were seen in the CO mixing ratio. By contrast, NOy values in 33% of the air masses were higher than those expected when stratospheric air intrusion is assumed to be a single source of NOy based on NOy‐O3 correlation analyses. This result suggests significant free tropospheric NOy sources, namely exhaust from the aircraft and NO production by lightning activity. In fact, spikes in the (NOx)mc mixing ratios were observed near the aircraft corridor south of Tokyo at an altitude of 10 km. These two free tropospheric NOx sources were considered to be important in determining the levels of the upper tropospheric NOx and NOy during PEM‐West B.

The Effect of Temperature on Promotion of the Oxidation of Nitric Oxide and Propene by the Thermal Decomposition of Peroxyacetyl Nitrate (PAN) under Dark Conditions

The Effect of Temperature on Promotion of the Oxidation of Nitric Oxide and Propene by the Thermal Decomposition of Peroxyacetyl Nitrate (PAN) under Dark Conditions

Promotion of the Oxidation of Nitric Oxide and Hydrocarbon by the Thermal Decomposition of Peroxyacetyl Nitrate (PAN) at Night

Abstract The decomposition of PAN in the presence of nitric oxide and propene in the air was investigated at 30 °C under dark conditions. The number of nitric oxide molecules oxidized per each PAN molecule decomposed varied from 3.7 to above 5 with increase of the ratio of initial concentration of propene to that of nitric oxide.

Thermal decomposition of peroxyacetyl nitrate in the presence of O2, NO2 and NO

The thermal decomposition of purePAN in N2 as well as in the presence of added O2, NO2 and NO was studied at 1 atm pressure. In addition to methyl nitrate, NO2 was a significant N-product of purePAN in N2 thermal decomposition. In the presence of sufficiently large amounts of O2, no methyl nitrate was formed at 333 K, indicating that the homolyticPAN decay to methyl nitrate and carbon dioxide is not occurring. In the presence of NO (in contrast to former studies) methyl nitrite was found to be the major organo-nitrogen compound instead of methyl nitrate. The systemPAN-NO-N2 allowed the determination of the rate constant 3.1 · 10−4s−1 at 298 K for reaction (1):PAN → CH3COO2+NO2, in agreement with prior studies. Computer simulations based on the free radical mechanism starting with reaction (1) fitted very well the experimental results.

Thermal decomposition of peroxyacetyl nitrate and reactions of acetyl peroxy radicals with nitric oxide and nitrogen dioxide over the temperature range 283-313 K

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal decomposition of peroxyacetyl nitrate and reactions of acetyl peroxy radicals with nitric oxide and nitrogen dioxide over the temperature range 283-313 KErnesto C. Tuazon, William P. L. Carter, and Roger AtkinsonCite this: J. Phys. Chem. 1991, 95, 6, 2434–2437Publication Date (Print):March 1, 1991Publication History Published online1 May 2002Published inissue 1 March 1991https://doi.org/10.1021/j100159a059RIGHTS & PERMISSIONSArticle Views321Altmetric-Citations52LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (420 KB) Get e-Alerts

The effect of temperature on ozone formation in the propene/nitrogen dioxide/air system

Abstract A series of laboratory experiments were conducted to determine whether the positive correlation observed in the ambient atmosphere between ozone and temperature could, in part, be due to a temperature dependency of the photochemical smog reaction kinetics. The experiments were conducted using the propene/NO2/air system in General Motors Research Laboratories’ dynamic irradiation chamber. Over the range of temperatures investigated, 10°C to 50°C, the maximum observed ozone concentration increased with increasing temperature from 10°C to 40°C. Between 40°C and 50°C there was no further increase in ozone. In contrast, it was observed that the amount of peroxyacetylnitrate formed decreased with increasing temperature. These observations can be attributed to the temperature dependence of the thermal decomposition of peroxyacetylnitrate. At low temperatures, the increased stability of this compound makes it a sink for nitrogen dioxide; conversely, at higher temperatures, peroxyacetylnitrate is too unst...

Thermal decomposition of peroxyacetylnitrate in the presence of nitric oxide

The thermal reactions occurring in mixtures containing peroxyacetyl nitrate and nitric oxide at part-per-million concentrations in synthetic air are investigated. In the presence of NO, peroxyacetylnitrate decomposes at a measurable rate at room temperature, with accompanying oxidation of NO to NO/sub 2/. The results can be explained by a mechanism involving the following reactions: CH/sub 3/COO/sub 2/NO/sub 2/ = CH/sub 3/COO/sub 2/ + NO/sub 2/ (1), CH/sub 3/COO/sub 2/ + NO/sub 2/ = CH/sub 2/COO/sub 2/NO/sub 2/ (2), and CH/sub 3/COO/sub 2/ + NO = CH/sub 3/CO/sub 2/ + NO/sub 2/ (3). The effect of variation of the NO/NO/sub 2/ ratio and the temperature on the rate of oxidation of NO to NO/sub 2/ allows evaluation of the rate constant ratio K2/k3 = 0.54 + or - 0.17 and the Arrhenius expression k1 = 10+(14.90 + or - 0.60) exp (-104.0 + or - 3.2 kj/rt)/s. Thermochemical kinetic considerations give an approximate value for the heat of formation of peroxyacetyl nitrate, (=-241 + or - 40 kj/mol) and for the absolute value of the rate constant k2 = 1.4 x 10-12 cm/sup 3//molecule/s at 300 K. The implications of these results for the behavior of peroxyacetyl nitrate in the laboratorymore » and in the atmosphere are discussed.« less