Formation of NH 3 and N 2 O in a modern natural gas three-way catalyst designed for heavy-duty vehicles: the effects of simulated exhaust gas composition and ageing

Nevalainen, Pauliina; Kinnunen, Niko M.; Kirveslahti, Anna; Kallinen, Kauko; Maunula, Teuvo; Keenan, Matthew; Suvanto, Mika

doi:10.1016/j.apcata.2017.12.017

Cited by 61 publications

(26 citation statements)

References 46 publications

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“…For the urban sites (Figure S12), the calculated SQTBA values were lower than rural sites (lighter color) suggested that the transported NH 3 was less important at the urban sites due to the significant local emissions, such as vehicle emissions, stationary source SCRs, and from domestic waste processing (Nevalainen et al, ; Thiruvengadam et al, ). The midwestern region of the United States was a likely NH 3 source area for spring, summer, and autumn, and eastern Pennsylvania and Maryland were important to the spring and summer values.…”

Section: Factors Affecting the Ammonia Concentrationsmentioning

confidence: 99%

“…These agricultural emissions can impact urban air pollution through atmospheric transport (Gu et al, 2014;Reche et al, 2012). In urban areas, major NH 3 emissions are due to nitrogen oxide (NO x ) emission control equipment, such as three-way catalysts (TWC) on light-duty vehicles (Nevalainen et al, 2018;Thiruvengadam et al, 2016) and selective catalytic reduction (SCR) systems on both stationary sources (Forzatti, 2001) and new heavy-duty diesel engines (Thiruvengadam et al, 2016). In a TWC, NH 3 is formed as a byproduct of incomplete reduction and emitted by both gasoline and natural gas vehicles (Sun et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

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Ambient Ammonia Concentrations Across New York State

Zhou

Holsen

et al. 2019

JGR Atmospheres

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Ammonia (NH3) was monitored at four locations (two urban and two rural) across New York State from April 2016 to October 2017 using active and passive systems. The two rural sites were Pinnacle State Park (PIN) and the Village of Potsdam, and the two urban sites were the City of Rochester and Queens College in New York City. Active and passive concentrations were well correlated across all sites (r2 = 0.866), but the active systems measured 6.2% higher NH3 concentrations. The mean (±SD) NH3 concentrations measured using active systems in Queens College, City of Rochester, Village of Potsdam, and PIN were 3.22 ± 2.23, 2.84 ± 1.91, 1.29 ± 1.12, and 0.82 ± 0.64 ppb, respectively. Ambient NH3 concentrations varied with diel vehicular and seasonal agricultural activities. NH3 concentrations at the urban sites had lower seasonal variability than the rural sites. NH3 concentrations were generally related to regional and in‐state NH3 emissions although less regional influence was observed at the urban sites. Local NH3 source directions were identified using conditional bivariate probability function. The urban sites were affected by local NH3 sources such as vehicular emissions and urban population centers. Likely distant NH3 source locations affecting the four sites were identified using simplified quantitative transport bias analysis model. Rural sites were more highly affected by transported NH3. Midwestern and Atlantic were major NH3 source areas. NH3 emissions from the south of PIN were probably due to the use of diesel trucks and other diesel engines in the hydraulic fracturing industry in Pennsylvania near the New York State border.

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Section: Factors Affecting the Ammonia Concentrationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ambient Ammonia Concentrations Across New York State

Zhou

Holsen

et al. 2019

JGR Atmospheres

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“…Ageing of these catalytic systems has been linked, among other factors, to high temperatures to which automobile catalyst are exposed during driving (up to 1000 • C), leading to loss of activity and oxygen storage performance and, thus, the formation of NH 3 mainly at high operating temperatures [51].…”

Section: Resultsmentioning

confidence: 99%

NH3 and CO Emissions from Fifteen Euro 6d and Euro 6d-TEMP Gasoline-Fuelled Vehicles

et al. 2022

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Ammonia (NH3) plays a key role in atmospheric chemistry and largely contributes to the PM2.5 measured in urban areas around the globe. For that reason, the National Emission Ceilings directive, Gothenburg Protocol under the United Nations Convention on Long-Range Transboundary Air Pollution, and International Panel for Climate Change (IPCC) directive required a reduction of the emissions of NH3. Nonetheless, the European Environment Agency (EEA) indicated that road transport emissions of NH3 have increased. Moreover, recent studies reported that, not only vehicle NH3 emissions are greater than agricultural emissions in areas that gather > 40% of the U.S. population, but urban emissions of NH3 for passenger cars are underestimated by a factor of 17 in UK. In this study, fifteen gasoline-fuelled vehicles, meeting the most recent European emission standards, Euro 6d or Euro 6d-TEMP, were investigated in laboratory tests over the type-approval worldwide-harmonized light-duty vehicles test cycle (WLTC), at 23 °C and −7 °C, as well as over the motorway cycle Bundesautobahn (BAB). Results show that all the vehicles tested emitted NH3 over the different duty cycles, and presented emissions level that are comparable to those previously reported for Euro 4–Euro 6b vehicles. Finally, good agreement between the CO and the NH3 emissions was registered during the acceleration events, and, in general, a fair correlation, with R2 > 0.75, was obtained, when comparing the CO and NH3 emissions of the studied vehicles.

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“…Apart from the concentration of gases participating in the reactions (1) and (2) (NO, CO, and H 2 ), the mass of NH 3 emission will be determined by the kinetics of these reactions depending on the temperature at which the NO converts to NH 3 . According to [5], reaction (3) takes place at lower TWC temperatures (300-500 • C), whereas reaction (4) occurs at higher temperatures (>500 • C).…”

Section: Introductionmentioning

confidence: 99%

Ammonia Emissions in SI Engines Fueled with LPG

Żółtowski

Gis

2021

Energies

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Ammonia is a toxic exhaust component emitted from internal combustion engines. Both pure ammonia and the products of its reaction with nitrogen and sulfur compounds, being the source of particulate matter (PM) emissions, are dangerous for human health and life. The aim of the article was to demonstrate that NH3 can be produced in exhaust gas after-treatment systems of spark-ignition (SI) engines used in light-duty vehicles. In some cases, NH3 occurs in high enough concentrations that can be harmful and dangerous. It would be reasonable to collect research data regarding this problem and consider the advisability of limiting these pollutant emissions in future regulations. The article presents the results of the spark-ignition engine testing on an engine test bench and discusses the impact of the air–fuel ratio regulation and some engine operating parameters on the concentration of NH3. It has been proven that in certain engine operating conditions and a combination of circumstances like the three-way catalytic reactor (TWC) temperature and periodic enrichment of the air–fuel mixture may lead to excessive NH3 emissions resulting from the NO conversion in the catalytic reactor. This is a clear disadvantage due to the lack of limitation of these pollutant emissions by the relevant type-approval regulations. This article should be a contribution to discussion among emissions researchers whether future emission regulations (e.g., Euro 7 or Euro VII) should include a provision to reduce NH3 emissions from all vehicles.

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Formation of NH 3 and N 2 O in a modern natural gas three-way catalyst designed for heavy-duty vehicles: the effects of simulated exhaust gas composition and ageing

Cited by 61 publications

References 46 publications

Ambient Ammonia Concentrations Across New York State

Ambient Ammonia Concentrations Across New York State

NH3 and CO Emissions from Fifteen Euro 6d and Euro 6d-TEMP Gasoline-Fuelled Vehicles

Ammonia Emissions in SI Engines Fueled with LPG

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