Mechanisms of the NO2 Formation  in Diesel Engines

Rößler, Michael; Koch, Thomas; Janzer, Corina; Olzmann, Matthias

doi:10.1007/s38313-017-0057-2

Cited by 19 publications

(11 citation statements)

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“…As described earlier, diesel engine systems primarily emit fuel sulfur as SO 2 so that, in principle, particulate sulfate is not formed until the release of the exhaust into the atmosphere (Pirjola et al, 2014;Moldanová et al, 2009). Following the emission into ambient air, SO 2 is oxidised by OH radicals and finally partitions into the particle phase mainly as H 2 SO 4 (see Reactions R6 to R8; Lovejoy et al, 1996), which was concluded in previous studies from the absence of NH + 4 and a significant fraction of sulfate-bound water in the particle phase (Petzold et al, 2008;Pokhrel and Lee, 2015;Schneider et al, 2007).…”

Section: Atmospheric Processes During Transport Of Ship Emission Plumesmentioning

confidence: 80%

“…Another important parameter for combustion efficiency is the combustion temperature: with increasing combustion temperature, combustion is more efficient, but more nitrogen oxides are produced. Furthermore, reduced oxidation of NO to NO 2 in the oxygen-deficient exhaust gas, which occurs after efficient combustion in the propulsion system, results in an increase in the NO to NO 2 ratio with increasing combustion efficiency (Rößler et al, 2017). According to the literature, a higher vessel speed, engine load, or engine power causes a higher peak combustion temperature in the engine system and thus more efficient fuel combustion (Cappa et al, 2014;Sinha et al, 2003).…”

Section: Influences Of Ship Properties and The Combustion Process On Ship Emission Plumesmentioning

confidence: 99%

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Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: in situ measurements in the Mediterranean Sea and around the Arabian Peninsula

et al. 2020

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Abstract. A total of 252 emission plumes of ships operating in the Mediterranean Sea and around the Arabian Peninsula were investigated using a comprehensive dataset of gas- and submicron-particle-phase properties measured during the 2-month shipborne AQABA (Air Quality and Climate Change in the Arabian Basin) field campaign in summer 2017. The post-measurement identification of the corresponding ship emission events in the measured data included the determination of the plume sources (up to 38 km away) as well as the plume ages (up to 115 min) and was based on commercially available historical records of the Automatic Identification System. The dispersion lifetime of chemically inert CO2 in the ship emission plumes was determined as 70±15 min, resulting in levels indistinguishable from the marine background after 260±60 min. Emission factors (EFs) as quantities that are independent of plume dilution were calculated and used for the investigation of influences on ship emission plumes caused by ship characteristics and the combustion process as well as by atmospheric processes during the early stage of exhaust release and during plume ageing. Combustion efficiency and therefore emission factors of black carbon and NOx were identified to depend mostly on the vessel speed and gross tonnage. Moreover, larger ships, associated with higher engine power, were found to use fuel with higher sulfur content and have higher gas-phase SO2, particulate sulfate, particulate organics, and particulate matter EFs. Despite the independence of EFs of dilution, a significant influence of the ambient wind speed on the particle number and mass EFs was observed that can be traced back to enhanced particle coagulation in the case of slower dilution and suppressed vapour condensation on particles in the case of faster dilution of the emission plume. Atmospheric reactions and processes in ship emission plumes were investigated that include NOx and O3 chemistry, gas-to-particle conversion of NOx and SO2, and the neutralisation of acids in the particle phase through the uptake of ambient gas-phase ammonia, the latter two of which cause the inorganic particulate content to increase and the organic fraction to decrease with increasing plume age. The results allow for us to describe the influences on (or processes in) ship emission plumes quantitatively by parameterisations, which could be used for further refinement of atmospheric models, and to identify which of these processes are the most important ones.

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Section: Atmospheric Processes During Transport Of Ship Emission Plumesmentioning

confidence: 80%

Section: Influences Of Ship Properties and The Combustion Process On Ship Emission Plumesmentioning

confidence: 99%

Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: in situ measurements in the Mediterranean Sea and around the Arabian Peninsula

et al. 2020

View full text Add to dashboard Cite

show abstract

“…∆y 2 is the standard second order central difference on a regular grid defined by the points (x i , y j ) with i, j comprised between 1 and N x , N y respectively. By Taylor expansion it is easy to verify that the scheme is a first order in time approximation consistent with problem (28). The asymmetric treatment of the product terms between different species as ψ n 3 ψ n+1 4 in the fourth equation, reduces the problem to the solution at each time iteration of a linear system of equations for each species and allows to avoid too restrictive conditions on the step ∆t such as ∆t ∼ 1/(k r ψ l ) for a large concentration ψ l .…”

Section: Diffusion Of Chemical Species In Airmentioning

confidence: 99%

“…For vehicle's emissions, the maximum NO 2 concentration is recorded at medium engine load and low engine speed. At high speed, the NO 2 emissions are reduced to a minimum (in most cases less than 4%) [28]. According to a recent study using British data [7], the fraction of NO 2 in vehicle NO x emissions (all fuels) increased from around 5-7% in 1996 to 15-16% in 2009.…”

Section: Algorithm 2 Estimates Of Emissions From Traffic Quantitiesmentioning

confidence: 99%

A computational modular approach to evaluate $ {\mathrm{NO_{x}}} $ emissions and ozone production due to vehicular traffic

Balzotti

Briani

Filippo

et al. 2022

DCDS-B

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The societal impact of traffic is a long-standing and complex problem. We focus on the estimation of ground-level ozone production due to vehicular traffic. We propose a comprehensive computational approach combining four consecutive modules: a traffic simulation module, an emission module, a module for the main chemical reactions leading to ozone production, and a module for the diffusion of gases in the atmosphere. The traffic module is based on a second-order traffic flow model, obtained by choosing a special velocity function for the Collapsed Generalized Aw-Rascle-Zhang model. A general emission module is taken from literature, and tuned on NGSIM data together with the traffic module. Last two modules are based on reaction-diffusion partial differential equations. The system of partial differential equations describing the main chemical reactions of nitrogen oxides presents a source term given by the general emission module applied to the output of the traffic module. We use the proposed approach to analyze the ozone impact of various traffic scenarios and describe the effect of traffic light timing. The numerical tests show the negative effect of vehicles restarts on emissions, and the consequent increase in pollutants in the air, suggesting to increase the length of the green phase of traffic lights.

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“…Another important parameter for combustion efficiency is the combustion temperature: With increasing combustion temperature, combustion is more efficient, but more nitrogen oxides are produced. Furthermore, reduced oxidation of NO to NO2 in the oxygen-deficient exhaust gas, which occurs after efficient combustion in the propulsion system, results in an increase of the NO to NO2 ratio with increasing combustion efficiency (Rößler et al, 2017). According to the literature, a higher vessel speed, engine load, or engine power causes a higher peak combustion temperature in the engine system and thus more efficient fuel combustion (Cappa et al, 2014;Sinha et al, 2003).…”

Section: Influences Of Ship Properties and The Combustion Process On mentioning

confidence: 99%

Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: In-situ measurements in the Mediterranean Sea and around the Arabian Peninsula

Celik¹,

Drewnick²,

Fachinger³

et al. 2019

Preprint

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Abstract. 252 emission plumes of ships operating in the Mediterranean Sea and around the Arabian Peninsula were investigated using a comprehensive dataset of gas and submicron particle phase properties measured during the two-month shipborne AQABA field campaign in summer 2017. The post-measurement identification of the corresponding ship emission events in the measured data included the determination of the plume sources (up to 38&#8201;km away) as well as of the plume ages (up to 115&#8201;min) and was based on commercially available historical records of the Automatic Identification System. The dispersion lifetime of chemically inert CO2 in the ship emission plumes was determined as (70&#8201;&#177;&#8201;15)&#8201;min, resulting in levels indistinguishable from the marine background after (260&#8201;&#177;&#8201;60)&#8201;min. Emission factors (EFs) as quantities that are independent of plume dilution were calculated and used for the investigation of influences on ship emission plumes caused by ship characteristics and the combustion process as well as by atmospheric processes during the early stage of exhaust release and during plume aging. Combustion efficiency and therefore emission factors of black carbon and NOx were identified to depend mostly on the vessel speed and gross tonnage. Moreover, larger ships, associated with higher engine power were found to use fuel with higher sulfur content and have higher gas phase SO2, particulate sulfate, particulate organics and particulate matter EFs. Despite the independence of EFs on dilution, significant influence of the ambient wind speed on the particle number and mass EFs was observed that can be traced back to enhanced particle coagulation in case of slower dilution and suppressed vapor condensation on particles in case of faster dilution of the emission plume. Atmospheric reactions and processes in ship emission plumes were investigated that include NOx and O3 chemistry, gas-to-particle conversion of NOx and SO2 and the neutralization of acids in the particle phase through the uptake of ambient gas phase ammonia, the latter two of which cause the inorganic particulate content to increase and the organic fraction to decrease with increasing plume age. The results enable identification of the most important influences on (or processes in) ship emission plumes and to describe those quantitatively by parameterizations, which could be used for further refinement of atmospheric models.

show abstract

Mechanisms of the NO2 Formation in Diesel Engines

Cited by 19 publications

References 0 publications

Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: in situ measurements in the Mediterranean Sea and around the Arabian Peninsula

Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: in situ measurements in the Mediterranean Sea and around the Arabian Peninsula

A computational modular approach to evaluate $ {\mathrm{NO_{x}}} $ emissions and ozone production due to vehicular traffic

Influence of vessel characteristics and atmospheric processes on the gas and particle phase of ship emission plumes: In-situ measurements in the Mediterranean Sea and around the Arabian Peninsula

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