| 1. |
- Baldi, Francesco, 1986, et al.
(author)
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The influence of propulsion system design on the carbon footprint of different marine fuels
- 2013
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In: Low Carbon Shipping Conference, London 2013.
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Conference paper (other academic/artistic)abstract
- Rising environmental awareness and stricter environmental regulations have increased the interest in new fuels and energy efficiency measures in the shipping industry. Different fuels have different physical and chemical properties that affect the performance of internal combustion engines, e.g. the efficiency, the exhaust gas emissions, and the potential for energy recovery. This has an impact on the potential propulsion efficiency as well as on the life cycle environmental performance. The aim of this study is therefore twofold. First, to assess the potential for optimising the energy use of the propulsion system dependent on fuel choice and second, to assess the overall life cycle global warming potential of the optimised systems. Three fuels are compared, heavy fuel oil (HFO), marine gas oil (MGO), and liquefied natural gas (LNG), in combination with two exhaust gas cleaning technologies, scrubbers and selective catalytic reduction (SCR) units. Data from one year of actual operation with a product tanker are used as a base for the optimization. The results show that the solution with the lowest fuel consumption and carbon footprint is a two-stroke engine with waste heat recovery (WHR) powered by LNG. The synthesis of an optimization procedure for the propulsion system and an LCA approach leads to very interesting results. The different carbon content of different fuels, together with methane slip, leads to a better estimation to the carbon footprint of different propulsion systems. On the other hand, a better insight of the differences between different propulsion arrangements allows performing a more accurate comparison between different fuels. The potential for WHR has a particularly relevant influence on the final result.
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| 2. |
- Bengtsson, Selma, 1984, et al.
(author)
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A comparative life cycle assessment of marine fuels: liquefied natural gas and three other fossil fuels
- 2011
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In: Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment. - : SAGE Publications. - 2041-3084 .- 1475-0902. ; 225:2, s. 97-110
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Journal article (peer-reviewed)abstract
- Air emissions from shipping have received attention in recent years and the shippingindustry is striving for solutions to reduce their emissions and to comply with stricter regulations.Strategies to reduce emissions can consist of a fuel switch, engine changes, or end-ofpipetechnologies, but they do not necessarily imply reduced life cycle emissions. The presentpaper assesses the environmental performance of marine fuels from well-to-propeller using lifecycle assessment (LCA). Four fossil fuels are compared: heavy fuel oil (HFO), marine gas oil,gas-to-liquid (GTL) fuel, and liquefied natural gas (LNG), combined with two exhaust abatementtechniques: open-loop scrubber and selective catalytic reduction. LNG and other alternativesthat comply with the SECA 2015 and Tier III NOx requirements give decreased acidification andeutrophication potentials with 78–90 per cent in a life cycle perspective compared with HFO. Incontrast, the use of LNG does not decrease the global warming potential by more than 8–20 percent, the amount depending mainly on the magnitude of the methane slip from the gas engine.None of the fossil fuels scrutinized here would decrease the greenhouse gas emissions significantlyfrom a life cycle perspective. The study supports the need for LCA when evaluating theenvironmental impact of a fuel change, e.g. it is found that the highest global warming potentialduring the whole life cycle is connected to the alternatives with GTL fuel.
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| 3. |
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| 4. |
- Bengtsson, Selma, 1984, et al.
(author)
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Environmental Assessment of Two Pathways Towards the Use of Biofuels in Shipping
- 2012
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In: Energy Policy. - : Elsevier BV. - 0301-4215. ; 44, s. 451-463
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Journal article (peer-reviewed)abstract
- The goal of this study is to evaluate the life cycle performance of two alternative pathways to biofuels in the shipping industry: the 'diesel route' and the 'gas route'. The diesel route comprises of a shift from heavy fuel oil to marine gas oil and then a gradual shift to biodiesel, whereas the gas route comprises of a shift to liquefied natural gas and then a gradual shift to liquefied biogas. The two routes are assessed in a case study for the ferry traffic between the Swedish mainland and the island Gotland. Life cycle assessment (LCA) is used to evaluate the environmental performance with the functional unit chosen to be one year of ro-pax ferry service, including both passenger and goods transportation. The gas route is indicated to have better overall environmental performance than the diesel route. Furthermore, use of biofuels is illustrated as one possible measure to decrease the global warming impact from shipping, but to the expense of greater environmental impact for some other impact categories. As an example, the global warming potential (GWP(100)) was shown to decrease with the use of biofuels in this study, while the eutrophication potential and the primary energy use increased.
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| 5. |
- Bengtsson, Selma, 1984, et al.
(author)
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Environmental feasibility of biogas and biodiesel as fuel for passenger ferries
- 2011
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In: SETAC Europe 17th LCA Case Study Symposium, 28 February -1March, Budapest. - 9789638667076 ; , s. 53-54
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Conference paper (other academic/artistic)abstract
- Mobility is important in our everyday life. Marine transportation has the potential to increase its level of sustainability, by implementing new cleaning technologies, increase its energy efficiency and/or by changing fuel. The ferry traffic between the Swedish mainland and the island Gotland has a unique opportunity to be a first mover with environmentally sustainable shipping solutions, as it is procured by the Swedish authority Rikstrafiken. The present contract expires in January 2015 and Rikstrafiken has therefore made an investigation regarding the future ferry traffic [1]. This investigation stresses long term economical, social and environmental sustainability as conditions for the future ferry traffic. One possible solution to come closer to environmental sustainability could be to use biogas as fuel. Biogas has shown good life cycle environmental performance as vehicle fuel (e.g.[2]), but the use of liquefied biogas on ships has not been tested or evaluated. Liquefaction is needed in order to have acceptable energy content per unit volume of the fuel, but the liquefaction process is energy intensive and costly [3]. Biodiesel is another possible solution to consider. Both biogas and biodiesel can be blended with fossil fuels (natural gas and diesel, respectively) [4]. Here the environmental performance of liquefied biogas and biodiesel are compared with marine gas oil and liquefied natural gas.
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| 6. |
- Bengtsson, Selma, 1984, et al.
(author)
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Fuels for short sea shipping: A comparative assessment with focus on environmental impact
- 2014
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In: Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment. - : SAGE Publications. - 2041-3084 .- 1475-0902. ; 228:1, s. 44-54
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Journal article (peer-reviewed)abstract
- Short sea shipping is facing harder requirements on exhaust emissions in the coming years as stricter regulations are enforced in some regions of the world. In addition, shortage of conventional fuels as well as restrictions on greenhouse gas emissions makes the search for new fuels of interest. The objective of this article is to assess important characteristics to evaluate when selecting fuels for short sea shipping. The following four criteria are considered: (1) local and regional environmental impacts, (2) overall environmental impact, (3) infrastructure and (4) fuel cost and competition with other transport modes. Special focus is put on environmental impact, and life cycle assessment is used for the environmental assessment. The fuels compared in this study are heavy fuel oil, marine gas oil, biomass-to-liquid fuel, rapeseed methyl ester, liquefied natural gas and liquefied biogas. This study shows that liquefied natural gas will reduce the local and regional environmental impacts more relative to the other fuels investigated here. Furthermore, liquefied biogas is found to be the most preferable if all envirtsonmental impact categories are considered. This study also highlights the importance to consider other impact categories for short sea shipping compared to deep sea shipping and shows that NOX emission is the dominant contributor to all assessed environmental impact categories with local and regional impac
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| 7. |
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| 8. |
- Bengtsson, Selma, 1984, et al.
(author)
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Life cycle assessment of marine fuels - A comparative study of four fossil fuels for marine propulsion
- 2011
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Reports (other academic/artistic)abstract
- Maritime transportation is facing harder requirements on fuel quality and exhaust emissions in the coming decades, especially in the Emission Control Areas (ECAs). To address these requirements the shipping industry will either need to use alternative fuels or implement exhaust abatement techniques. Consequently, the maritime sector within ECAs is on the verge of a fuel and/or technology shift in the near future. At the same time, there is limited information regarding marine fuels’ overall environmental impact during their life cycle.The overall aim of this report is therefore to investigate the environmental performance of maritime fuels from a life cycle perspective. This has been done through a life cycle assessment (LCA) of four possible fossil marine fuels combined with two exhaust gas cleaning techniques. The geographical location is set to the North Sea and the Baltic Sea and the time perspective is 2015 to 2020.The following fuel alternatives are assessed:• Heavy fuel oil with a sulphur content of 1% (base scenario)• Heavy fuel oil with a sulphur content of 1% with a scrubber (fulfils the regulation within the sulphur ECAs 2015)• Marine gas oil with a sulphur content of 0.1% (fulfils the regulation within the sulphur ECAs 2015)• Marine gas oil with a sulphur content of 0.1 % with a selective catalytic reduction unit (fulfils the regulation within the sulphur ECAs 2015 and the Tier III regulation for nitrogen oxide emissions)• Liquefied natural gas (fulfils the regulation within the sulphur ECAs 2015 and the Tier III regulation for nitrogen oxide emissions)• Gas-to-liquid produced by the Fischer-Tropsch process (fulfils the regulation within the sulphur ECAs 2015)• Gas-to-liquid diesel produced by the Fischer-Tropsch process with a selective catalytic reduction unit (fulfils the regulation within the sulphur ECAs 2015 and the Tier III regulation for nitrogen oxide emissions)It is shown that the “use phase”, i.e. the combustion of marine fuels, is the dominant contributor to the overall environmental impact. Two main results are robust during all the modelled scenarios. Firstly, the global warming potential of the compared fuels are of the same order of magnitude. Maritime transportation with LNG as fuel can be attributed to comparable or a somewhat lower global warming potential than the other fuels depending on modelling choices. Secondly, the potential contribution to acidification and eutrophication is significantly lower for fuel alternatives that fulfil the Tier III requirement regarding nitrogen oxide emissions, i.e. the LNG fuel alternatives and the fuel alternatives with selective catalytic reduction units.A problematic issue related to LCA is how to allocate the impact from crude oil refining into marine fuels. This is problematic since there is a wide diversity of refineries and since the choice of allocation method could change the result. The problem is specific for marine fuels since they only contribute to a small part of a refinery’s overall impact. It is therefore suggested to perform a separate study with focus on how future changes in refinery production and different allocation methods will change the environmental impact of crude oil based fuels. It is also recommended that a study with a longer time perspective is carried out, in order to evaluate what fuels that are desirable in the future and what fuel properties that are important.
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| 9. |
- Bengtsson, Selma, 1984
(author)
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Life Cycle Assessment of Present and Future Marine Fuels
- 2011
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Licentiate thesis (other academic/artistic)abstract
- Interest in new fuels for marine propulsion is growing, mainly as a result of stricter environmental regulations but also due to increased attention to air pollution, greenhouse gas emissions and the uncertainty of future oil supply. Several different fuels and exhaust abatement technologies are proposed for marine transportation, all of which have different advantages and disadvantages in relation to the environment and human health. It is interesting to assess the upstream environmental impact of a fuel change in order to avoid problem shifting from one phase in the life cycle to another.Life Cycle Assessment (LCA) is a common tool for environmental assessments of products and services and it addresses the potential environmental impact of a product or service from a cradle-to-grave perspective. LCA is already well established for evaluating alternative fuels for road transportation. It is therefore considered an appropriate tool for assessing the environmental performance of marine fuels. Here, LCA has been used in two different studies for assessing the environmental impact of marine fuels.In the first study, Paper I, the life cycle environmental impact of changing fuel and/or installing abatement techniques in order to comply with upcoming environmental regulations is explored. The alternatives investigated were heavy fuel oil with and without scrubber, marine gas oil with and without selective catalytic reduction, liquefied natural gas and synthetic diesel with and without selective catalytic reduction. This study thus only involved fossil fuels and indicated that the global warming potential of the investigated fuels are of the same order of magnitude. The best overall environmental performance was reached, not surprisingly, for the fuels that fulfil the most stringent upcoming environmental regulations: liquefied natural gas and marine gas oil with SCR. Synthetic diesel was ruled out as being too energy intensive.In the second study, Paper II, two routes, a diesel route and a gas route, towards the use of renewable fuels in the shipping industry were investigated. The study started from the traditional fuel used today: heavy fuel oil. For 2015, two possible paths were assessed: marine gas oil and liquefied natural gas. For 2020, these fuels were blended with a small proportion of a first-generation biofuel of the same type, and for 2025 they were fully replaced with a second-generation biofuel. This study indicated that the gas route has better overall environmental performance than the diesel route. The study also illustrated that biofuels are one possible measure to decrease the global warming impact from shipping but that it can be at the expense of greater environmental impact from other impact categories.
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| 10. |
- Grahn, Maria, 1963, et al.
(author)
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Cost-effective choices of marine fuels under stringent carbon dioxide targets
- 2013
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In: Proceedings of 3rd International conference on technologies, operations, logistics and modelling in Low Carbon Shipping, University College London..
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Conference paper (other academic/artistic)abstract
- In order to investigate cost-effective choices of future marine fuels in a carbon constrained world, the linear optimisation model of the global energy system, GET-RC 6.1, has been modified to GET-RC 6.2, including a more detailed representation of the shipping sector. In this study the GET-RC 6.2 model was used to assess what fuel/fuels and propulsion technology options for shipping are cost-effective to switch to when achieving global stabilisation of atmospheric CO2 concentrations at 400 ppm. The aim is to investigate (i) when is it cost-effective to start to phase out the oil from the shipping sector and what determines the speed of the phase out, (ii) under what circumstances are LNG or methanol cost-effective replacers and (iii) the role of bioenergy as a marine fuel. In our base analysis we analyse results from assuming that CCS will be large-scale available in future as well as if it will not. In the sensitivity analysis different parameters have been varied in order to investigate which impact for example different supply of primary energy sources and different costs for different transportation technologies will have on the choice of fuels in the shipping sector. Three main conclusions are presented (i) it seems to be cost-effective to start to phase out the oil from the shipping sector nearest decades, (ii) natural gas based fuels, i.e. fossil methanol and LNG are the two most probable replacers, of which methanol has been shown to dominate in the case with CCS (methanol or LNG depends on the availability of natural gas, on the methane slip and on infrastructure costs) and (iii) limited supply and competition for bioenergy among other end use sectors makes the contribution of bioenergy small, in the shipping sector.
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