| 1. |
- Parsmo, Rasmus, et al.
(författare)
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BRAVE ECO – Benchmark for Reduction of Anchoring Vessels’ Emissions – Enabling Change of Operation
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This feasibility study aims to evaluate the possibilities to reduce air emissions from ships anchored in port areas and, then especially the Port of Gothenburg. For this purpose, the study uses two main approaches. Firstly, it analyses the reasons and legal/business aspects for anchoring. Secondly, this study develops a reproducible calculation model for anchored vessels' CO2 emissions. Regulation of anchoring sites are not entirely clear since international regulation partly applies, also it is not clear who is responsible for the anchoring sites. This implies that the port´s scope of action is limited mainly to the ships that are calling the port. However, also emission from other ships at in the port area has been evaluated in this study to get a broader perspective. This pre-study provides both qualitative and quantitative findings and it is produced using mixed methods, including workshops with relevant port stakeholders. It also involves different scientific disciplines and several authors from the Port of Gothenburg Authority, IVL Swedish Environmental Research Institute, Maritime Studies at Chalmers University of Technology and the School of Business, Economics and Law at the University of Gothenburg. Furthermore, in connection to this study, one bachelor's thesis and two master's theses have been carried out. The results show that it is mainly tanker ships that are anchoring in Gothenburg and that their main reasons for anchoring are related to awaiting Laycan or waiting for an available berth. The companies involved in the study generally combine time charter and voyage charter contracts to access vessel capacity. The inputs from the workshops, the interviews conducted with stakeholders and the international literature are “rather” consistent: combining just in time arrival with slow steaming has a great potential for making a business case and to reduce fuel consumption and thereby emissions. However, there are many barriers which needs to be addressed, such as: lack of trust, improving information sharing (actors now communicate via phone or email), loss of income (due to demurrage), attitudes in the industry, the “first come, first serve” concept, risk of missing estimated time of arrival and port infrastructure. Even if there are many barriers, several actors in the port already have experience of combining just in time arrival and slow steaming. In this study, we develop a reproducible emission calculation model that calculates CO2eq emissions. The emissions are partly calculated by using the ships’ positions (AIS-data) from 2019, to extract the time spent at anchor. The emission model calculates the anchored vessels' total CO2eq emissions, but the model also calculates the theoretical potential for avoiding emission by using the time at anchor to slow steam. The results show that all tanker ships that anchored outside the port in 2019, could theoretically have reduced their emissions with about 30 ktonnes CO2eq, if they would have been notified of delays 24 hours before arrival and then reduced their speed to 10 knots. The results also show that using time to slow steam have a much greater potential to reduce emissions than if the ships would only reduce the time at anchor (by using fewer ships to perform the same transport work). This is especially true for the initial speed reductions (10-14 knots). This study also evaluates the emission calculation methods and assesses the uncertainties, by comparing different sources and underlying assumptions with real world data. The study argues that it is problematic to just use default values proposed in the global emission inventory issued by the International Maritime Organization (IMO). Using default values for estimating emission makes it harder to estimate the real effect of a new policy, regulation, or incentive in the port. However, a better emission inventory requires that on-board visits are made or that data is obtained digitally. The largest calculation uncertainties now are for boiler fuel consumption and bunker ships fuel consumption at the anchorage areas.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Beecken, Jörg, 1982, et al.
(författare)
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Airborne emission measurements of SO2, NOx and particles from individual ships using a sniffer technique
- 2014
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 7:7, s. 1957-1968
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Tidskriftsartikel (refereegranskat)abstract
- A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircraft. The system has been adapted for fast response measurements at 1 Hz, and the use of several of the instruments is unique. The uncertainty of the given data is about 20% for SO2 and 24% for NOx emission factors. The mean values with one standard deviation for multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8+/-6.5 g kg(fuel)(-1), 66.6+/-23.4 g kg(fuel)(-1) and 1.8+/-1.3 1016 particles kg(fuel)(-1) for SO2, NOx and particle number, respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 45 and 54 nm dependent on the distance to the source, and the number size distribution is monomodal. Concerning the sulfur fuel content, around 85% of the monitored ships comply with the International Maritime Organization (IMO) limits. The reduction of the sulfur emission control area (SECA) limit from 1.5 to 1% in 2010 appears to have contributed to reduction of sulfur emissions that were measured in earlier studies from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring.
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| 5. |
- 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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| 6. |
- 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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| 7. |
- Donahue, N. M., et al.
(författare)
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Aging of biogenic secondary organic aerosol via gas-phase OH radical reactions
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:34, s. 13503-13508
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Tidskriftsartikel (refereegranskat)abstract
- The Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) tested the hypothesis that hydroxyl radical (OH) aging significantly increases the concentration of first-generation biogenic secondary organic aerosol (SOA). OH is the dominant atmospheric oxidant, and MUCHACHAS employed environmental chambers of very different designs, using multiple OH sources to explore a range of chemical conditions and potential sources of systematic error. We isolated the effect of OH aging, confirming our hypothesis while observing corresponding changes in SOA properties. The mass increases are consistent with an existing gap between global SOA sources and those predicted in models, and can be described by a mechanism suitable for implementation in those models.
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| 8. |
- Flagiello, Domenico, et al.
(författare)
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A Novel Approach to Reduce the Environmental Footprint of Maritime Shipping
- 2021
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Ingår i: Journal of Marine Science and Application. - : Springer Science and Business Media LLC. - 1993-5048 .- 1671-9433. ; 20:2, s. 229-247
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Tidskriftsartikel (refereegranskat)abstract
- Maritime shipping is a strategic sector with a strong international vocation and management. The need to define regulations valid for many different countries without generating disparities of treatment slowed down the formulation of environmental regulations, especially for atmospheric emissions. In particular, regulations pertaining to the reduction of sulphur compounds allowed two distinct approaches: the use of low-sulphur fuels or exhaust gas cleaning systems, the so-called Scrubbers. The actual implementation of these solutions presents specific concerns either related to the toxicity of atmospheric by-products and to the fuel cost or to the generation of polluting washwaters that may need treatment before discharge. In this paper we analyzed the potential environmental benefit deriving from the use of a distillate fuel, not compliant with current IMO Sulphur Regulations, together with a Scrubber. The pilot-scale experimental results indicated that a limited amount of water and/or scrubber volume is needed to reduce sulphur emissions below regulations on maritime shipping, especially with the addition of NaOH reaching a water-saving between 25%-33% compared to the use of pure seawater. Experiments indicated that scrubber washwater PAHs emissions are within the available water quality standards indicated by EU and USA guidelines. A bottom-up analysis on heavy metals concentration shed light on the prominent role of metal-parts corrosion on the washwater emissions. Taking into account for corrosion phenomena, the actual heavy metals concentration in the washwater deriving from scrubbing was normally below the water quality standards.
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| 9. |
- Flagiello, Domenico, et al.
(författare)
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Effect of seawater alkalinity on the performances of a marine diesel engine desulphurization scrubber
- 2021
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Ingår i: Chemical Engineering Transactions. - 2283-9216 .- 2283-9216. ; 86, s. 505-510
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Tidskriftsartikel (refereegranskat)abstract
- Since the last fifteen years, Flue Gas Desulphurization (FGD) plants based on seawater scrubbing found an interesting application in the maritime transportation, as an answer to the stringent regulations imposed by International Maritime Organization (IMO) on sulphur emissions. This work reports the experimental results on desulphurization in a pilot seawater scrubber (DN 400) from a marine Diesel engine (80 kW) operated under different loads (10, 25 and 50%). The pilot scrubber was fed with a gas velocity 0.15 m/s and a liquid to gas mass ratio 1-3 kg/kg. The scrubbing liquid was available at different alkalinity and salinity levels representing the ion speciation of marine water in different geographic areas. The experiments evaluate the SO2 removal efficiency of the scrubber as a function of seawater alkalinity and pH. Finally, the paper reports a correlation to assess the seawater flow rate required to comply with the current IMO restrictions. This correlation allows tuning the seawater flow rate during the ship navigation based on the registered marine alkalinities and to the operating conditions of the engine. The model can be integrated in the scrubber control system to identify optimal operating conditions and reduce pumping costs, helping to reduce the EEDI and the SEEMP ships energy indexes.
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| 10. |
- Fridell, Erik, 1963, et al.
(författare)
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Measurements of abatement of particles and exhaust gases in a marine gas scrubber
- 2016
-
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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| 11. |
- Fridell, Erik, 1963, et al.
(författare)
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Measurements of Emissions to Air from a Marine Engine Fueled by Methanol
- 2021
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Ingår i: Journal of Marine Science and Application. - : Springer Science and Business Media LLC. - 1993-5048 .- 1671-9433. ; 20:1, s. 38-143
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Tidskriftsartikel (refereegranskat)abstract
- Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation. The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit. The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines. The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm. About 93% of the particles are evaporated and absorbed when using a thermodenuder, and thus a large majority of the particles are volatile. Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.
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| 12. |
- García-Gómez, Elisa, et al.
(författare)
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Characterization of scrubber water discharges from ships using comprehensive suspect screening strategies based on GC-APCI-HRMS
- 2023
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Ingår i: Chemosphere. - 0045-6535 .- 1879-1298. ; 343
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Tidskriftsartikel (refereegranskat)abstract
- An extended suspect screening approach for the comprehensive chemical characterization of scrubber discharge waters from exhaust gas cleaning systems (EGCSs), used to reduce atmospheric shipping emissions of sulphur oxides, was developed. The suspect screening was based on gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) and focused on the identification of polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives (alkyl-PAHs), which are among the most frequent and potentially toxic organic contaminants detected in these matrices. Although alkyl-PAHs can be even more abundant than parent compounds, information regarding their occurrence in scrubber waters is scarce. For compound identification, an in-house compound database was built, with 26 suspect groups, including 25 parent PAHs and 23 alkyl-PAH homologues. With this approach, 7 PAHs and 12 clusters of alkyl-PAHs were tentatively identified, whose occurrence was finally confirmed by target analysis using GC coupled with tandem mass spectrometry (GC-MS/MS). Finally, a retrospective analysis was performed to identify other relevant (poly)cyclic aromatic compounds (PACs) of potential concern in scrubber waters. According to it, 18 suspect groups were tentatively identified, including biphenyls, dibenzofurans, dibenzothiophenes and oxygenated PAHs derivatives. All these compounds could be used as relevant markers of scrubber water contamination in heavy traffic marine areas and be considered as potential stressors when evaluating scrubber water toxicity.
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| 13. |
- Lennartson, Anders, 1980, et al.
(författare)
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(3-acetylpyridine-kappa N)chlorobis(triphenylphosphine-kappa P) copper(I): a suitable candidate for absolute asymmetric synthesis?
- 2006
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Ingår i: Acta Crystallographica Section E-Structure Reports Online. ; 62
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Tidskriftsartikel (refereegranskat)abstract
- It was found that 3-acetylpyridine is capable of displacing triphenylphosphine from [CuCl(PPh3)(3)], forming the title compound, [CuCl(C7H7NO)(C18H15P)(2)]. The two triphenylphosphine ligands possess the same sense of chirality, and the molecules are therefore conformationally chiral. The compound was found to crystallize as a racemate (centrosymmetric space group) under the crystallization conditions employed. The molecular structure shows that the carbonyl C atom is blocked at one side by a triphenylphosphine ligand, while the other face is open for nucleophilic attack. Obtaining chiral crystals of the title compound is thus a future objective. In the crystal structure, C-(HO)-O-...(=C)-bonded dimers are formed, which are further stabilized by pi-pi interactions. The dimers form infinite chains through weak C-H-...pi interactions.
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| 14. |
- Lennartson, Anders, 1980, et al.
(författare)
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catena-Poly[[(3-acetylpyridine)copper(I)]mu(3)-chloro]
- 2005
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Ingår i: Acta Crystallographica Section E-Structure Reports Online. ; 61
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Tidskriftsartikel (refereegranskat)abstract
- In the search for ketone complexes suitable for absolute asymmetric synthesis, that is, complexes crystallizing in Sohncke space groups, we have studied complexes between copper( I) halides and acetylpyridines. The structure of polymeric [CuCl(3-acpy)](n) (3-acpy is 3-acetylpyridine, C7H7NO), a compound which was found to form achiral chains crystallizing in a centrosymmetric space group, is reported here. The complex forms ladder-type chains, in which the Cu-I atom is coordinated by one N atom and three Cl atoms in a tetrahedral geometry. In the crystal structure, the chains are interconnected through C - H....Cl and C - H.....O intermolecular contacts.
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| 15. |
- 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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| 16. |
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| 17. |
- Pathak, Ravi K., et al.
(författare)
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Influence of Ozone and Radical Chemistry on Limonene Organic Aerosol Production and Thermal Characteristics
- 2012
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Ingår i: Environmental Science & Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 46:21, s. 11660-11669
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Tidskriftsartikel (refereegranskat)abstract
- Limonene has a strong tendency to form secondary organic aerosol (SOA) in the atmosphere and in indoor environments. Initial oxidation occurs mainly via ozone or OH radical chemistry. We studied the effect of O3 concentrations with or without a OH radical scavenger (2-butanol) on the SOA mass and thermal characteristics using the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures and a volatility tandem differential mobility analyzer. The SOA mass using 15 ppb limonene was strongly dependent on O3 concentrations and the presence of a scavenger. The SOA volatility in the presence of a scavenger decreased with increasing levels of O3, whereas without a scavenger, there was no significant change. A chemical kinetic model was developed to simulate the observations using vapor pressure estimates for compounds that potentially contributed to SOA. The model showed that the product distribution was affected by changes in both OH and ozone concentrations, which partly explained the observed changes in volatility, but was strongly dependent on accurate vapor pressure estimation methods. The model–experiment comparison indicated a need to consider organic peroxides as important SOA constituents. The experimental findings could be explained by secondary condensed-phase ozone chemistry, which competes with OH radicals for the oxidation of primary unsaturated products.
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| 18. |
- Salo, Kent, 1967, et al.
(författare)
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Aerosol volatility and enthalpy of sublimation of carboxylic acids.
- 2010
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Ingår i: The journal of physical chemistry. A. - : American Chemical Society (ACS). - 1520-5215 .- 1089-5639. ; 114:13, s. 4586-94
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Tidskriftsartikel (refereegranskat)abstract
- The enthalpy of sublimation has been determined for nine carboxylic acids, two cyclic (pinonic and pinic acid) and seven straight-chain dicarboxylic acids (C(4) to C(10)). The enthalpy of sublimation was determined from volatility measurements of nano aerosol particles using a volatility tandem differential mobility analyzer (VTDMA) set-up. Compared to the previous use of a VTDMA, this novel method gives enthalpy of sublimation determined over an extended temperature range (DeltaT approximately 40 K). The determined enthalpy of sublimation for the straight-chain dicarboxylic acids ranged from 96 to 161 kJ mol(-1), and the calculated vapor pressures at 298 K are in the range of 10(-6)-10(-3) Pa. These values indicate that dicarboxylic acids can take part in gas-to-particle partitioning at ambient conditions and may contribute to atmospheric nucleation, even though homogeneous nucleation is unlikely. To obtain consistent results, some experimental complications in producing nanosized crystalline aerosol particles were addressed. It was demonstrated that pinonic acid "used as received" needed a further purification step before being suspended as a nanoparticle aerosol. Furthermore, it was noted from distinct differences in thermal properties that aerosols generated from pimelic acid solutions gave two types of particles. These two types were attributed to crystalline and amorphous configurations, and based on measured thermal properties, the enthalpy of vaporization was 127 kJ mol(-1) and that of sublimation was 161 kJ mol(-1). This paper describes a new method that is complementary to other similar methods and provides an extension of existing experimental data on physical properties of atmospherically relevant compounds.
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| 19. |
- 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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| 20. |
- Salo, Kent, 1967
(författare)
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Physical properties and processes of secondary organic aerosol and its constituents
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Atmospheric aerosol particles are involved in several important processes including the formation of clouds and precipitation. A considerable fraction of the ambient aerosol mass consists of organic compounds of both primary and secondary origin. These organic compounds are often semi-volatile and susceptible to oxidation which makes the organic aerosol a dynamic system, both chemically and physically. Once an aerosol is formed or released into the atmosphere, several processes will begin to alter its chemical and physical properties. The focus of the work presented in this thesis has been to use experimental methods to characterise single aerosol components and more complex experimental systems, involving the formation and processing of secondary organic aerosol (SOA). The volatility of aerosol particles, e.g. the evaporation rate of the particles upon heating, can provide information of several important properties. From an aerosol consisting only of one pure compound it is possible to derive physical quantities like saturation vapour pressure and enthalpy of evaporation. In more complex systems like a secondary organic aerosol the volatility can give information about changes in composition, state of oxidation and degree of internal or external mixing. With the use of a volatility tandem differential mobility analyser (VTDMA), the saturation vapour pressures and enthalpies of evaporation have been determined for pure compounds that are known constituents of ambient aerosol samples i.e. nine carboxylic acids. Two of them were cyclic, pinic and pinonic acid and seven of them were straight chain dicarboxylic acids with number of carbons ranging from C4 to C10. These properties were in addition evaluated for the aminium nitrates of mono-, di-, and trimethylamine, ethyl- and monoethanolamine. The calculated saturation vapour pressures for the carboxylic acids were in the range of 10-6 to 10-3 Pa and the determined enthalpies of evaporation ranged from 83 to 161 kJ mol-1. The corresponding values for the aminium nitrates were for the calculated saturation vapour pressures approximately 10-4 Pa and for the enthalpies of evaporation 54 to 72 kJ mol-1. The VTDMA system has also been utilised to characterise SOA formed in the AIDA and SAPHIRE smog chambers from the ozonolysis of α-pinene and limonene and the change in the SOA thermal properties during OH radical induced ageing. Further, the effect of elevated ozone concentration and radical chemistry on SOA formed from limonene ozonolysis in the G-FROST laminar flow reactor was investigated. In addition, to compare with vapour pressures of aminium nitrates SOA generated from photooxodation of alkyl amines have been characterised in the EUPHORE smog chamber. The calculated vapour pressures of all the investigated pure compounds in this work characterise them to be in the semi-volatile organic compound (SVOC) category; hence they will be present both in the gaseous and condensed phase in the atmosphere. This implied that all these compounds will be susceptible for gas phase OH radical oxidation that was demonstrated to be an important process for the complex mixtures investigated in the smog chamber facilities. The OH chemistry was also influencing the volatility of aerosol produced in G-FROST by ozonlysis. Regarding photooxodation of amines the aerosols produced under high NOx conditions initially mimicked the pure salts but was efficiently transformed by oxidation into an aerosol with similar volatility properties as observed in the terpene oxidation experiments.
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| 21. |
- Salo, Kent, 1967, et al.
(författare)
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Thermal characterization of aminium nitrate nanoparticles.
- 2011
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Ingår i: The journal of physical chemistry. A. - : American Chemical Society (ACS). - 1520-5215 .- 1089-5639. ; 115:42, s. 11671-7
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Tidskriftsartikel (refereegranskat)abstract
- Amines are widely used and originate from both anthropogenic and natural sources. Recently, there is, in addition, a raised concern about emissions of small amines formed as degradation products of the more complex amines used in CO(2) capture and storage systems. Amines are bases and can readily contribute to aerosol mass and number concentration via acid-base reactions but are also subject to gas phase oxidation forming secondary organic aerosols. To provide more insight into the atmospheric fate of the amines, this paper addresses the volatility properties of aminium nitrates suggested to be produced in the atmosphere from acid-base reactions of amines with nitric acid. The enthalpy of vaporization has been determined for the aminium nitrates of mono-, di-, trimethylamine, ethylamine, and monoethanolamine. The enthalpy of vaporization was determined from volatility measurements of laboratory generated aerosol nanoparticles using a volatility tandem differential mobility analyzer set up. The determined enthalpy of vaporization for aminium nitrates range from 54 up to 74 kJ mol(-1), and the calculated vapor pressures at 298 K are around 10(-4) Pa. These values indicate that aminium nitrates can take part in gas-to-particle partitioning at ambient conditions and have the potential to nucleate under high NO(x) conditions, e.g., in combustion plumes.
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| 22. |
- Salo, Kent, 1967, et al.
(författare)
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Volatility of secondary organic aerosol during OH radical induced ageing
- 2011
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Ingår i: Atmos. Chem. Phys. - : Copernicus GmbH. ; 11, s. 11055-11067
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate oxidation of SOA formed from ozonolysis of α-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of α-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME) was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of α-pinene and limonene initially was rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the α-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA) were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise the importance of gas phase oxidation of semi- or intermediate-volatile organic compounds (SVOC and IVOC) for atmospheric aerosol ageing.
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| 23. |
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| 24. |
- Santos, Luis F.E.d., et al.
(författare)
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Changes in CCN activity of ship exhaust particles induced by fuel sulfur content reduction and wet scrubbing
- 2022
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Ingår i: Environmental Science: Atmospheres. - : Royal Society of Chemistry (RSC). - 2634-3606. ; 3:1, s. 182-195
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Tidskriftsartikel (refereegranskat)abstract
- Maritime transport remains a large source of airborne pollutants, including exhaust particles that can act as cloud condensation nuclei (CCN). While primary diesel engine exhaust particles are generally considered hydrophobic, international regulations targeting a reduction of particulate emissions from ships may have secondary effects, and therefore influence how exhaust interacts within the atmosphere. The effect of international fuel sulfur content (FSC) regulations on the cloud forming abilities of exhaust particles was investigated using a marine test engine operating on compliant low FSC fuels, non-compliant high FSC distillate fuels and in conjunction with a marine wet scrubber (fresh- and seawater). Particle sizing and liquid droplet activation measurements reveal that compliance measures can have opposing effects on the CCN activity of exhaust particles. For a non-compliant, high FSC fuel, wet scrubbing leads to an increase in CCN activity but not to significant increases in CCN emission factors. However, switching to low FSC fuels resulted in emissions of highly hydrophobic particles, causing a significant reduction in CCN activity resulting in smaller CCN emission factors by at least one order of magnitude. Our observations are supported by chemical analysis of exhaust particles using scanning transmission X-ray microscopy and near edge X-ray absorption fine structure (STXM/NEXAFS) spectra. Potential implications of effects on ship exhaust particles for cloud and climate interactions due to different compliance measures are discussed.
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| 25. |
- Santos, Luis F. E. D., et al.
(författare)
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Quantification and physical analysis of nanoparticle emissions from a marine engine using different fuels and a laboratory wet scrubber
- 2022
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Ingår i: Environmental Sciences: Processes and Impacts. - : Royal Society of Chemistry (RSC). - 2050-7895 .- 2050-7887. ; 24:10, s. 1769-1781
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Tidskriftsartikel (refereegranskat)abstract
- A marine test-bed diesel engine was used to study how international fuel sulfur content (FSC) regulations and wet scrubbing can affect physical properties of submicron exhaust particles. Particle size distributions, particle number and mass emission factors as well as effective densities of particulate emissions were measured for three distillate fuels of varying FSC and a laboratory wet scrubber. While particle number concentrations were reduced by up to 9% when switching to low FSC fuels, wet scrubbing led to increased ultrafine particulate emissions (<30 nm). Exhaust processed through the scrubber was also found to have particles with greater effective densities, a result that directly contradicts the particulate characteristics of low FSC fuel emissions. The results demonstrate that alternative pathways to comply with marine FSC regulations can have opposing effects and thus may have very different implications for important atmospheric processes. The relevance for air quality, and the potential implications for cloud and climate interactions are discussed.
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