scholarly journals Chemical composition and radiative properties of nascent particulate matter emitted by an aircraft turbofan burning conventional and alternative fuels

2019 ◽  
Vol 19 (10) ◽  
pp. 6809-6820 ◽  
Author(s):  
Miriam Elser ◽  
Benjamin Tobias Brem ◽  
Lukas Durdina ◽  
David Schönenberger ◽  
Frithjof Siegerist ◽  
...  
Keyword(s):  
Optical Properties ◽  
Particulate Matter ◽  
Chemical Composition ◽  
Alternative Fuels ◽  
Radiative Properties ◽  
Total Carbon ◽  
Low Thrust ◽  
Scattering Coefficients ◽  
Fuel Blends ◽  
Wide Range

Abstract. Aircraft engines are a unique source of carbonaceous aerosols in the upper troposphere. There, these particles can more efficiently interact with solar radiation than at ground. Due to the lack of measurement data, the radiative forcing from aircraft exhaust aerosol remains uncertain. To better estimate the global radiative effects of aircraft exhaust aerosol, its optical properties need to be comprehensively characterized. In this work we present the link between the chemical composition and the optical properties of the particulate matter (PM) measured at the engine exit plane of a CFM56-7B turbofan. The measurements covered a wide range of power settings (thrust), ranging from ground idle to take-off, using four different fuel blends of conventional Jet A-1 and hydro-processed ester and fatty acids (HEFA) biofuel. At the two measurement wavelengths (532 and 870 nm) and for all tested fuels, the absorption and scattering coefficients increased with thrust, as did the PM mass. The analysis of elemental carbon (EC) and organic carbon (OC) revealed a significant mass fraction of OC (up to 90 %) at low thrust levels, while EC mass dominated at medium and high thrust. The use of HEFA blends induced a significant decrease in the PM mass and the optical coefficients at all thrust levels. The HEFA effect was highest at low thrust levels, where the EC mass was reduced by up to 50 %–60 %. The variability in the chemical composition of the particles was the main reason for the strong thrust dependency of the single scattering albedo (SSA), which followed the same trend as the fraction of OC to total carbon (TC). Mass absorption coefficients (MACs) were determined from the correlations between aerosol light absorption and EC mass concentration. The obtained MAC values (MAC532=7.5±0.3 m2 g−1 and MAC870=5.2±0.9 m2 g−1) are in excellent agreement with previous literature values of absorption cross section for freshly generated soot. While the MAC values were found to be independent of the thrust level and fuel type, the mass scattering coefficients (MSCs) significantly varied with thrust. For cruise conditions we obtained MSC532=4.5±0.4 m2 g−1 and MSC870=0.54±0.04 m2 g−1, which fall within the higher end of MSCs measured for fresh biomass smoke. However, the latter comparison is limited by the strong dependency of MSC on the particles' size, morphology and chemical composition. The use of the HEFA fuel blends significantly decreased PM emissions, but no changes were observed in terms of EC∕OC composition and radiative properties.

scholarly journals Chemical composition, optical properties and radiative forcing efficiency of nascent particulate matter emitted by an aircraft turbofan burning conventional and alternative fuels

2018 ◽  
Author(s):  
Miriam Elser ◽  
Benjamin T. Brem ◽  
Lukas Durdina ◽  
David Schönenberger ◽  
Frithjof Siegerist ◽  
...  
Keyword(s):  
Optical Properties ◽  
Particulate Matter ◽  
Chemical Composition ◽  
Radiative Forcing ◽  
Alternative Fuels ◽  
Measurement Data ◽  
Particulate Emissions ◽  
Low Thrust ◽  
Fuel Blends ◽  
Wide Range

Abstract. Aircraft engines are a unique source of carbonaceous aerosols in the upper troposphere. There, these particles can more efficiently interact with solar radiation than at ground. Due to the lack of measurement data, the radiative forcing from aircraft particulate emissions remains uncertain. To better estimate the global radiative effects of aircraft exhaust aerosol, its optical properties need to be comprehensively characterized. In this work we present the link between the chemical composition and the optical properties of the particulate matter (PM) measured at the engine exit plane of a CFM56-7B turbofan. The measurements covered a wide range of power settings (thrust), ranging from ground idle to take-off, using four different fuel blends of conventional Jet A-1 and Hydro-processed Ester and Fatty Acids (HEFA) biofuel. At the two measurement wavelengths (532 and 870 nm) and for all tested fuels, the absorption and scattering coefficients increased with thrust, as did the PM mass. The separation of elemental carbon (EC) and organic carbon (OC) revealed a significant mass fraction of OC (up to 90 %) at low thrust levels, while EC mass dominated at medium and high thrust. The use of HEFA blends induced a significant decrease in the PM mass and the optical coefficients at all thrust levels. The HEFA effect was highest at low thrust levels, where the EC mass was reduced by up to 50–60 %. The variability in the chemical composition of the particles was the main reason for the strong thrust dependency of the single scattering albedo (SSA), which followed the same trend as the OC fraction. Mass absorption coefficients (MAC) were determined from the correlations between aerosol light absorption and EC mass concentration. The obtained MAC values (MAC532 = 7.5 ± 0.3 m2 g−1 and MAC870 = 5.2 ± 0.9 m2 g−1) are in excellent agreement with previous literature values of absorption cross section for freshly generated soot. The Simple Forcing Efficiency (SFE) was used to evaluate the direct radiative effect of aircraft particulate emissions for various ground surfaces. The results indicate that aircraft PM emissions over highly reflective surfaces like snow or ice have a substantial warming effect. The use of the HEFA fuel blends decreased PM emissions, but no changes where observed in terms of EC/OC composition, optical properties and forcing per mass emitted.

Emission Distribution and Regulation of Local Heat Source

2012 ◽  
Vol 326-328 ◽  
pp. 330-334 ◽  
Author(s):  
Jan Valíček ◽  
Jana Müllerová ◽  
Vlastimil Kuběna ◽  
Pavel Koštial ◽  
Marta Harničárová ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Human Health ◽  
Fossil Fuels ◽  
Local Heating ◽  
Point Of View ◽  
Total Production ◽  
Economic Point ◽  
Automated Method ◽  
Wide Range

Pollutants can be classified according to their chemical composition, harmfulness, hazardousness, risk rate and toxicity. The most monitored pollutants are particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NOx), sulfur dioxide (SO2), organic substances which are in the form of gaseous phase in waste gases expressed as total organic carbon, dibenzodioxins and dibenzofurans [1-3]. Other pollutants are divided into several groups and subgroups, such as substances with carcinogenic effects (asbestos, Co, Cd, Be, Ni, As, Cr, dioxins, etc.), solid inorganic contaminants (He, Se, animony, and others) and inorganic pollutants in the form of gases (HCl, HF, ammonia, etc.), organic gases and vapours (phenol, toluene, acetone and many others) and gases causing the greenhouse effect (CO2, methane, N2O, hydrofluorocarbons, etc.). The term particulate matter, or suspended matter refers to the emissions of a wide range of wind drift solids and liquid particles of material in size from several nanometres up to 0.5 mm, which stay in the air for some time. This is a major component of atmospheric pollution, which contributes to harmful effects not only on human health but also on intensity of materials degradation. Into the atmosphere, where we can meet them, regardless of particle size and chemical composition, in the form of a complex heterogeneous mixture, they are released from burning fossil fuels and also from burning biomass-based fuels, while domestic heating accounts for about 16% of the total production of particulate matter [4,5,6]. This percentage represents a degree of imperfect combustion of fuels used in local heating. Emissions from incomplete combustion are undesirable from the point of view of human health as well as from the economic point of view, because this leads to the degradation of materials. Nevertheless, since fuel combustion is necessary for the society, emissions are still produced. This paper presents an automated method of perfect combustion control in local heating in order to minimize emissions being produced.

Characterization of Emissions From the Use of Alternative Aviation Fuels

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Tak W. Chan ◽  
Wajid A. Chishty ◽  
Pervez Canteenwalla ◽  
David Buote ◽  
Craig R. Davison
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Environmental Sustainability ◽  
Alternative Fuels ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Alternative Aviation Fuels ◽  
Significant Difference ◽  
Particulate Matter Emissions

Alternative fuels for aviation are now a reality. These fuels not only reduce reliance on conventional petroleum-based fuels as the primary propulsion source, but also offer promise for environmental sustainability. While these alternative fuels meet the aviation fuels standards and their overall properties resemble those of the conventional fuel, they are expected to demonstrate different exhaust emissions characteristics because of the inherent variations in their chemical composition resulting from the variations involved in the processing of these fuels. This paper presents the results of back-to-back comparison of emissions characterization tests that were performed using three alternative aviation fuels in a GE CF-700-2D-2 engine core. The fuels used were an unblended synthetic kerosene fuel with aromatics (SKA), an unblended Fischer–Tropsch (FT) synthetic paraffinic kerosene (SPK) and a semisynthetic 50–50 blend of Jet A-1 and hydroprocessed SPK. Results indicate that while there is little dissimilarity in the gaseous emissions profiles from these alternative fuels, there is however a significant difference in the particulate matter emissions from these fuels. These differences are primarily attributed to the variations in the aromatic and hydrogen contents in the fuels with some contributions from the hydrogen-to-carbon ratio of the fuels.

scholarly journals Characteristics of Aerosol during a Severe Haze-Fog Episode in the Yangtze River Delta: Particle Size Distribution, Chemical Composition, and Optical Properties

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 56 ◽  
Author(s):  
Ankang Liu ◽  
Honglei Wang ◽  
Yi Cui ◽  
Lijuan Shen ◽  
Yan Yin ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Chemical Composition ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Soluble ◽  
Air Masses ◽  
Soluble Ions ◽  
Wide Range ◽  
Water Soluble Ions

Particle size distribution, water soluble ions, and black carbon (BC) concentration in a long-term haze-fog episode were measured using a wide-range particle spectrometer (WPS), a monitor for aerosols and gases (MARGA), and an aethalometer (AE33) in Nanjing from 16 to 27 November, 2018. The observation included five processes of clean, mist, mix, haze, and fog. Combined with meteorological elements, the HYSPLIT model, and the IMPROVE model, we analyzed the particle size distribution, chemical composition, and optical properties of aerosols in different processes. The particle number size distribution (PNSD) in five processes differed: It was bimodal in mist and fog and unimodal in clean, mix, and haze. The particle surface area size distribution (PSSD) in different processes showed a bimodal distribution, and the second peak of the mix and fog processes shifted to a larger particle size at 480 nm. The dominant air masses in five processes differed and primarily originated in the northeast direction in the clean process and the southeast direction in the haze process. In the mist, mix, and fog processes local air masses dominated. NO3− was the primary component of water soluble ions, with the lowest proportion of 45.6% in the clean process and the highest proportion of 53.0% in the mix process. The ratio of NH4+ in the different processes was stable at approximately 23%. The ratio of SO42− in the clean process was 26.2%, and the ratio of other processes was approximately 20%. The average concentration of BC in the fog processes was 10,119 ng·m−3, which was 3.55, 1.80, 1.60, and 1.46 times that in the processes of clean, mist, mix, and haze, respectively. In the different processes, BC was primarily based on liquid fuel combustion. NO3−, SO42−, and BC were the main contributors to the atmospheric extinction coefficient and contributed more than 90% in different processes. NO3− contributed 398.43 Mm−1 in the mix process, and SO42− and BC contributed 167.90 Mm−1 and 101.19 Mm−1, respectively, during the fog process.

Characterization of Emissions From the Use of Alternative Aviation Fuels

2015 ◽  
Author(s):  
Tak W. Chan ◽  
Wajid A. Chishty ◽  
Pervez Canteenwalla ◽  
David Buote ◽  
Craig R. Davison
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Environmental Sustainability ◽  
Alternative Fuels ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Alternative Aviation Fuels ◽  
Significant Difference ◽  
Particulate Matter Emissions

Alternative fuels for aviation are now a reality. These fuels not only reduce reliance on conventional petroleum-based fuels as the primary propulsion source, but also offer promise for environmental sustainability. While these alternative fuels meet the aviation fuels standards and their overall properties resemble those of the conventional fuel, they are expected to demonstrate different exhaust emissions characteristics because of the inherent variations in their chemical composition resulting from the variations involved in the processing of these fuels. This paper presents the results of back-to-back comparison of emissions characterization tests that were performed using three alternative aviation fuels in a GE CF-700-2D-2 engine core. The fuels used were an unblended synthetic kerosene fuel with aromatics (SKA), an unblended Fischer Tropsch synthetic paraffinic kerosene (SPK) and a semi-synthetic 50-50 blend of Jet A-1 and hydroprocessed SPK. Results indicate that while there is little dissimilarity in the gaseous emissions profiles from these alternative fuels, there is however a significant difference in the particulate matter emissions from these fuels. These differences are primarily attributed to the variations in the aromatic and hydrogen contents in the fuels with some contributions from the hydrogen-to-carbon ratio of the fuels.

scholarly journals Optical Properties, Chemical Composition and the Toxicological Potential of Urban Particulate Matter

2017 ◽  
Vol 17 (6) ◽  
pp. 1515-1526 ◽  
Author(s):  
Máté Pintér ◽  
Zoltán Bozóki ◽  
László Manczinger ◽  
Csaba Vágvölgyi ◽  
Eszter Horváth ◽  
...  
Keyword(s):  
Optical Properties ◽  
Particulate Matter ◽  
Chemical Composition ◽  
Urban Particulate Matter

scholarly journals Chemical Characteristics of Fine Particulate Matter in Poland in Relation with Data from Selected Rural and Urban Background Stations in Europe

2018 ◽  
Vol 9 (1) ◽  
pp. 98 ◽  
Author(s):  
Barbara Błaszczak ◽  
Kamila Widziewicz-Rzońca ◽  
Natalia Zioła ◽  
Krzysztof Klejnowski ◽  
Katarzyna Juda-Rezler
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Western Europe ◽  
Chemical Constituents ◽  
Fine Particulate Matter ◽  
Total Carbon ◽  
Urban Background ◽  
Rural Background ◽  
Rural And Urban ◽  
Inorganic Aerosol

Air pollution by particulate matter (PM) is recognized as a one of the most important environmental issue. A particular attention is being paid to fine PM fraction (PM2.5, PM1.0) due to its detrimental impact on human health and long-term persistence in the air. Presented work is an in-depth bibliometric study on the concentrations and chemical composition of PM2.5 among 27 rural and 38 urban/urban background stations dispersed across the Europe. Obtained results indicate that the chemical composition of PM2.5, in terms of mass concentrations and percentage contribution of main chemical constituents, is relatively different in various parts of Europe. Urban and urban background stations are typically characterized by higher share of total carbon (TC) in PM2.5, compared to rural background sites, mostly pronounced during the heating periods. The share of the secondary inorganic aerosol (SIA) is typically higher at rural background stations, especially in North-Western Europe. In general, the relative contribution of SIA in PM2.5 mass, both at rural and urban background stations, showed more or less pronounced seasonal variation, opposite to Polish measurement sites. Moreover, Poland stands out from the majority of the European stations by strong dominance of total carbon over secondary inorganic aerosol.

scholarly journals Optical-chemical relationships for carbonaceous aerosols observed at Jeju Island, Korea with a 3-laser photoacoustic spectrometer

2010 ◽  
Vol 10 (4) ◽  
pp. 9369-9389 ◽  
Author(s):  
B. A. Flowers ◽  
M. K. Dubey ◽  
C. Mazzoleni ◽  
E. A. Stone ◽  
J. J.. Schauer ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Composition ◽  
Radiative Forcing ◽  
Optical Model ◽  
Index Of Refraction ◽  
Enhanced Absorption ◽  
Aerosol Absorption ◽  
Photoacoustic Spectrometer ◽  
Wide Range ◽  
Pollution Plumes

Abstract. Transport of aerosols in pollution plumes from the mainland Asian continent was observed in situ at Jeju, South Korea during the Cheju Asian Brown Cloud Plume-Asian Monsoon Experiment (CAPMEX) field campaign throughout August and September 2008 using a 3-laser photoacoustic spectrometer. Transport of mixed sulfate, carbonaceous, and nitrate aerosols from various Asian pollution plumes to Jeju accounted for 76% of the deployment days, showing large variations in their measured chemical and optical properties. Our analysis of eight distinct episodes, spanning a wide range of chemical composition, optical properties, and source regions, reveals that at episodes with higher OC/SO2−4 and NO−3/SO2−4 composition ratios exhibit lower single scatter albedo at shorter wavelengths (ω405); significantly lower [ω405meas = 0.79±0.06, ω405calc = 0.86±0.01] than predicted by an optical model that assumes constant complex index of refraction with wavelength (an optical model of soot). We attribute this discrepancy to enhanced absorption by organic material. Organic carbon absorption accounts for up to 50% of the measured aerosol absorption at 405 nm for the high OC/SO2−4 episode. Coatings of elemental carbon aerosol cores are hypothesized to increase absorption by factors up to 6 at visible wavelengths. Carbonaceous aerosol absorption can alter global radiative forcing estimates substantially, underscoring the need to understand and predict chemical composition effects on optical properties.

scholarly journals The influence of emission sources on particulate matter pollution in adjacent areas

2019 ◽  
pp. 253-258
Author(s):  
Valeriu Danciulescu ◽  
Luoana Florentina Pascu ◽  
Mihaela Petrescu ◽  
Andreea Cozea ◽  
Raluca Diodiu ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Anthropogenic Activities ◽  
Ambient Air ◽  
Industrial Plant ◽  
Emission Sources ◽  
Adjacent Area ◽  
Wide Range ◽  
Neighbouring Area ◽  
Particulate Matter Pollution

Particulates generated by anthropogenic activities are found in the ambient air in varying amounts, in a wide range of sizes and in a wide variety of chemical composition. The concentration of particulates at one site, as well as their composition, are influenced by their origin and dispersion factors. By chemical and dimensional analysis of particulates in an area, we can draw preliminary conclusions about the origin and level of pollution in that area. This paper presents the results obtained by concomitant monitoring of particulates emissions and the concentration of particulate matter in ambient air in the adjacent area of an industrial plant. The result of the measurements obtained and their correlation with the specific conditions during the monitoring period lead us to the conclusion that the concentration of particulate matter at the emission sources directly influences the concentrations of particulate matter in the neighbouring area.

Sign in / Sign up

Export Citation Format

Share Document