| 1. |
- Anderson, Maria, 1983, et al.
(författare)
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Characterization of particles from a marine engine operating at low loads
- 2015
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1873-2844 .- 1352-2310. ; 101, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Particle emissions from a marine diesel engine operating at low loads with four different fuels were characterized with respect to particle number (PN) and particle mass (PM), size distribution, volatility and chemical composition. The four different fuels used were Swedish Environmental class 1 (MK1) and class 3 diesel (MK3), heavy fuel oil (HFO, 0.12 wt% S) and marine diesel oil (MDO, 0.52 wt% S). The measurements were performed for a marine diesel engine in a test-bed engine lab and the particle emissions were measured with an Engine Exhaust Particle Sizer and a Dust Monitor, giving the number concentrations in the size range of 5.6-560 nm and 300 nm to 20 gm, respectively. To quantify the amount of solid particles a thermodenuder was used. Additionally, filter samples were taken for gravimetric, black carbon (BC) and elemental analysis. The particle emissions showed a bimodal size distribution by number and the number concentrations were dominated by nanoparticles (diameter (Dp) 50 nm generally were solid primary particles. Combustion of HFO resulted in the highest PN and PM concentrations. Emission factors (EFs) for PM and PN for both the total particle emissions and the fraction of primary, solid particles are presented for different fuels and loads. EFs for nitrogen oxides (NOx), BC and some elements (Ca, Fe, V, Ni, Zn) are presented as well. This study contributes to understanding particle emissions from potential future fuels as well as emissions in ports and coastal areas where lower engine loads are common.
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| 2. |
- Anderson, Maria, 1983, et al.
(författare)
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Particle- and Gaseous Emissions from an LNG Powered Ship
- 2015
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 49:20, s. 12568-12575
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of particle number and mass concentrations and number size distribution of particles from a ship running on liquefied natural gas (LNG) were made on-board a ship with dual-fuel engines installed. Today there is a large interest in LNG as a marine fuel, as a means to comply with sulfur and NOX regulations. Particles were studied in a wide size range together with measurements of other exhaust gases under different engine loads and different mixtures of LNG and marine gas oil. Results from these measurements show that emissions of particles, NOX, and CO2 are considerably lower for LNG compared to present marine fuel oils. Emitted particles were mainly of volatile character and mainly had diameters below 50 nm. Number size distribution for LNG showed a distinct peak at 9-10 nm and a part of a peak at diameter 6 nm and below. Emissions of total hydrocarbons and carbon monoxide are higher for LNG compared to present marine fuel oils, which points to the importance of considering the methane slip from combustion of LNG.
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| 3. |
- Beecken, Jörg, 1982, et al.
(författare)
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Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling
- 2015
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 15:9, s. 5229-5241
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Tidskriftsartikel (refereegranskat)abstract
- Emission factors of SO2, NOx and size-distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an Mi-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the Neva River in the urban area of Saint Petersburg. Most ships were running at reduced speed (10 kn), i.e., not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal, with averages of 4.6 and 18.2 gSO(2) kg(fuel)(-1) for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content Sulfur Emission Control Areas (SECA) limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal, with an average of 58 gNO(x) kg(fuel)(-1). The corresponding emission related to the generated power yields an average of 12.1 gNO(x) kWh(-1). The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 mu m size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm and the other for above 2 mu m. The average particle emission factors were found to be in the range from 0.7 to 2.7 x 10(16) particles kg(fuel)(-1) and 0.2 to 3.4 gPM kg(fuel)(-1), respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Regarding particulate mass, the values of the modeled data are about 2-3 times higher than the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the City of Saint Petersburg when carrying out atmospheric modeling, and using these measurements it was possible to better assess the impact of shipping on air quality.
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| 4. |
- Bilde, M., et al.
(författare)
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Saturation Vapor Pressures and Transition Enthalpies of Low-Volatility Organic Molecules of Atmospheric Relevance: From Dicarboxylic Acids to Complex Mixtures
- 2015
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 115:10, s. 4115-4156
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Forskningsöversikt (refereegranskat)abstract
- There are a number of techniques that can be used that differ in terms of whether they fundamentally probe the equilibrium and the temperature range over which they can be applied. The series of homologous, straight-chain dicarboxylic acids have received much attention over the past decade given their atmospheric relevance, commercial availability, and low saturation vapor pressures, thus making them ideal test compounds. Uncertainties in the solid-state saturation vapor pressures obtained from individual methodologies are typically on the order of 50-100%, but the differences between saturation vapor pressures obtained with different methods are approximately 1-4 orders of magnitude, with the spread tending to increase as the saturation vapor pressure decreases. Some of the dicarboxylic acids can exist with multiple solid-state structures that have distinct saturation vapor pressures. Furthermore, the samples on which measurements are performed may actually exist as amorphous subcooled liquids rather than solid crystalline compounds, again with consequences for the measured saturation vapor pressures, since the subcooled liquid phase will have a higher saturation vapor pressure than the crystalline solid phase. Compounds with equilibrium vapor pressures in this range will exhibit the greatest sensitivities in terms of their gas to particle partitioning to uncertainties in their saturation vapor pressures, with consequent impacts on the ability of explicit and semiexplicit chemical models to simulate secondary organic aerosol formation.
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| 5. |
- Fridell, Erik, 1963, et al.
(författare)
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Measurements of abatement of particles and exhaust gases in a marine gas scrubber
- 2016
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Ingår i: Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment. - : SAGE Publications. - 2041-3084 .- 1475-0902. ; 230:1, s. 154-162
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of exhaust gases from a marine engine equipped with an open-loop wet scrubber using seawater for sulphur dioxide (SO2) abatement are reported. The scrubber reduces the SO2 emissions effectively to levels corresponding to
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| 6. |
- Lindgren, Fredrik, 1979, et al.
(författare)
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The natural environment and human impacts
- 2016
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Ingår i: Shipping and the Environment: Improving Environmental Performance in Marine Transportation. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783662490457 ; , s. 29-74
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To comprehend the implications of the various environmental issues that man is inducing on the Earth (with a focus on the shipping industry), an understanding of the Earth's major systems is necessary. The natural environment, which consists of air, water, land and living organisms, is a dynamic system in which material and energy are exchanged within and between the individual components. The system is divided into four spheres (atmosphere, hydrosphere, geosphere, and biosphère), and fluxes of energy and material are exchanged amongst these spheres. The spheres also largely govern the fate of various environmental problems originating from the shipping industry. Therefore, background information related to these spheres is provided, and their major properties and implications are explained. Regarding the atmosphere, radiation and energy budgets are explained in conjunction with the weather and climate. Concerning the hydrosphere, oceanography is introduced together with marine ecology. Addressing the geosphere, the elements in the Earth's crust and mineral commodities are discussed. Regarding the biosphere, energy is transferred through food chains; the differences between life in water and life on land are examined. Energy flows through and is stored in these spheres; this stored energy is essential to the natural environment and human society. The different primary energy sources are described and divided into non-renewable and renewable sources. Finally, an introduction to human impacts on the natural environment and to major environmental issues is provided.
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| 7. |
- Salo, Kent, 1967, et al.
(författare)
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Emissions to the air
- 2016
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Ingår i: Shipping and the Environment: Improving Environmental Performance in Marine Transportation. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783662490457 ; , s. 169-227
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Seeing the black smoke coming out of the funnel of a manoeuvring ship makes it easy to understand that the ship's propulsion contributes to the emission of air pollutants. However, there is more than meets the eye going up in smoke. A vast majority of ships use fossil fuels, increasing a positive net contribution of carbon dioxide to the atmosphere when they are combusted. Because the fuels that are used are often of low quality and possess a high sulphur content, a number of other air pollutants are also emitted. Emissions to the air from ships include greenhouse gases (such as carbon dioxide, methane and nitrous oxide), sulphur and nitrogen oxides, with both acidifying and eutrophication effects, and different forms of particles, with impacts on health and climate. However, not all emissions to the atmosphere from ships originate from the combustion of fuels for propulsion and energy production. The handling of crude oil as cargo and compounds used in refrigeration systems cause emissions of volatile organic compounds and ozone-depleting substances. The sources of the most important emissions and relevant regulations are described in this chapter.
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| 8. |
- Sjöblom, Jonas, 1968, et al.
(författare)
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Particulate emissions from aromatic containing fuels
- 2016
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Ingår i: 20th ETH-Conference on Combustion Generated Nanoparticles.
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Konferensbidrag (refereegranskat)abstract
- PM emissions are increasingly important, especially for marine applications. As the legislations for fuel sulphur content is introduced in the SECA region, the focus was turned into the effects of aromatics. Aromatic fuel is known to increase PM emissions, but preliminary tests of drop-in aromatics in a marine diesel engine resulted in lower PM emissions. The objective in this presentation is to further investigate the interplay between fuel properties and the engine operations in order to try to explain the lowered PM emissions. By using ignition improver, the RoHR analysis showed very similar combustion (cylinder global phenomena) for the different fuels containing varying amounts of aromatics. oThis indicates that differences are due to local phenomena in the flame front, i.e. the difference is in the soot formation (rather than differences in soot oxidation)oThe PM emissions were lower for aromatic fuels in contrast to “common belief”. The reasons for better pre-mixing for aromatic fuels can be different and future investigation will try to pin-point the most plausible explanation, (see Figure 5). Possible explanations include:Lower molecular weight of aromatics (compared to diesel fuel) will make use of less oxygen in the air, hence lower equivalence ratio and less soot formation Physical properties such as density, viscosity and surface tension may also influence the spray break-up and contribute to a lower equivalence ratio. Furthermore, the influence of cavitation inside the nozzle may vary depending on fuel properties.•The trend of lower PM emissions for aromatic fuel could be “broken” by a different injection strategy (here: rail pressure):oWhen Pinj is sufficiently high, the effect of efficient pre-mixing (and hence shorter residence time at soot formation conditions) is dominating over increased soot formation due to presence of aromatic compounds (pre-cursors in soot formation).oWhen Pinj is lower (toward more traditional injection pressures found in older diesel engines), the increased soot formation due to aromatics dominates over increased pre-mixing.•By changing the operating conditions to exclude EGR, the comparison was improved and furthermore, the existence of nucleation mode particles could further help understand the fate of the soot formation
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| 9. |
- Wilewska-Bien, Magda, 1977, et al.
(författare)
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Measures to reduce discharges and emissions
- 2016
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Ingår i: Shipping and the Environment: Improving Environmental Performance in Marine Transportation. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783662490457 ; , s. 341-396
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Discharges and émissions from shipping can be reduced through different technical measures, many of which apply similar principies, e.g., filtration or absorption. Ballast water treatment systems can be used to limit the spread of invasive species. Selective catalytic reduction units and exhaust gas recirculation can be used to reduce nitrogen oxide emissions, and scrubbers and diesel particulate filters can be used to reduce sulphur dioxide and particle emissions. The restoration or remediation of natural environments may also be required after large oil spills. Possible remediation methods include booms, mechanical techniques and dispersant chemicals. These and several additional technical measures to reduce discharges and emissions are described in this chapter, including measures to reduce the impact of the infrastructure related to the shipping industry.
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| 10. |
- Zetterdahl, Maria, 1983, et al.
(författare)
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Impact of aromatic concentration in marine fuels on particle emissions
- 2017
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Ingår i: Journal of Marine Science and Application. - : Springer Science and Business Media LLC. - 1993-5048 .- 1671-9433. ; 16:3, s. 352-361
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Tidskriftsartikel (refereegranskat)abstract
- The fuel sulfur content in marine fuels has been regulated in Sulfur Emission Control Areas (SECAs) since January 2015. However, other fuel characteristics are also believed to have an impact on particle emissions, particularly on the number of particles emitted. This study investigates the impact of the content of aromatics in fuel. To achieve fuel blends with concentrations of aromatics similar to those found in marine fuel oils, i.e. 20%–30% by volume (%vol.), normal diesel oil (4%–5% vol. aromatics) is doped with a mixture of aromatics. Emission measurements are conducted in test-bed engine facilities and particle emissions over a wide size range are analyzed. Results show a decreased number of particles emitted (or not change) with an increase in the aromatic concentration in fuel. This is because there is a reduction in the cetane number of the fuel with an increased aromatic content, which effects the combustion process and results in decreased particle formation. However, when ignition improver is used to increase the cetane number, particle emissions remain at a lower level than for normal diesel oil; thereby emphasizing the presence of other factors in the formation of particles.
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