| 1. |
- Kanchiralla, Fayas Malik, 1989, et al.
(författare)
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How do variations in ship operation impact the techno-economic feasibility and environmental performance of fossil-free fuels? A life cycle study
- 2023
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Ingår i: Applied Energy. - : Elsevier Ltd. - 1872-9118 .- 0306-2619. ; 350
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Tidskriftsartikel (refereegranskat)abstract
- Identifying an obvious non-fossil fuel solution for all ship types for meeting the greenhouse gas reduction target in shipping is challenging. This paper evaluates the technical viability, environmental impacts, and economic feasibility of different energy carriers for three case vessels of different ship types: a RoPax ferry, a tanker, and a service vessel. The energy carriers examined include battery-electric and three electro-fuels (hydrogen, methanol, and ammonia) which are used in combination with engines and fuel cells. Three methods are used: preliminary ship design feasibility, life cycle assessment, and life cycle costing. The results showed that battery-electric and compressed hydrogen options are not viable for some ships due to insufficient available onboard space for energy storage needed for the vessel's operational range. The global warming reduction potential is shown to depend on the ship type. This reduction potential of assessed options changes also with changes in the carbon intensity of the electricity mix. Life cycle costing results shows that the use of ammonia and methanol in engines has the lowest life cycle cost for all studied case vessels. However, the higher energy conversion losses of these systems make them more vulnerable to fluctuations in the price of electricity. Also, these options have higher environmental impacts on categories like human toxicity, resource use (minerals and metals), and water use. Fuel cells and batteries are not as cost-competitive for the case vessels because of their higher upfront costs and shorter lifetimes. However, these alternatives are less expensive than alternatives with internal combustion engines in the case of higher utilization rates and fuel costs.
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| 2. |
- Kanchiralla, Fayas Malik, 1989, et al.
(författare)
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Life-Cycle Assessment and Costing of Fuels and Propulsion Systems in Future Fossil-Free Shipping
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:17, s. 12517-12531
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Tidskriftsartikel (refereegranskat)abstract
- Future ships need to operate with low or possibly zero greenhouse gas (GHG) emissions while ensuring low influence on other environmental impacts and that the operation is economically feasible.This study conducts a life-cycle evaluation of potential decarbonization solutions involving selected energy carriers (electrolytic hydrogen, electro-ammonia, electro-methanol, and electricity) in different propulsion system setups (engines, fuel cells, and carbon capture technologies) in terms of environmental impact and costs.The results of the study show that the assessed decarbonization options are promising measures to reduce maritime GHG emissions with low-carbon-intensive electricity.The same order of GHG reduction is shown to be possible independent of the propulsion system and energy carrier used onboard.However, the carbon abatement cost ranges from 300 to 550 €/tCO2eq, and there is a trade-off with environmental impacts such as human toxicity (cancer and non-cancer effects) and freshwater ecotoxicity mainly linked with the wind infrastructure used for electricity production.Electro-ammonia in fuel cells is indicated to be effective in terms of the carbon abatement cost followed by the so-called HyMethShip concept.The higher abatement cost of all options compared to current options indicates that major incentives and policy measures are required to promote the introduction of alternative fuel and propulsion systems.
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| 3. |
- Kanchiralla, Fayas Malik, 1989
(författare)
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Life cycle navigation through future energy carriers and propulsion options for the energy transition in shipping
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The shipping industry's heavy reliance on fossil fuels has a detrimental effect on the global climate, human health, and the natural environment. The shipping sector now relies on the use of cheap and energy-dense heavy fuel oil and is perceived as ‘difficult-to-decarbonize’. Presently the shipping sector is adopting incremental emission reduction measures related to operational and technological energy efficiency solutions. However, to meet the global climate target, the transition from fossil-based marine fuels to renewable energy carriers is needed. Electro-fuels, which are produced from low-carbon electricity, or direct use of electricity with battery storage, are two pathways for energy transition included in this thesis. This thesis aims to assess the possible influence of the above two decarbonization paths based on energy demand, environmental performance, and economic performance across the whole life cycle of ships. The assessment is performed for hydrogen, ammonia, methanol, and battery-electric on three case study vessels using prospective life cycle assessment (pLCA) and life cycle costing (LCC). The pLCA is based on systems thinking used for the environmental assessment of emerging technologies that are in an early stage of development, and the LCC is used for the economic assessment of technologies over the life cycle based on the same systems thinking. To understand the environmental and economic tradeoffs for decision making an integrated assessment of pLCA and LCC is employed in the thesis. Considering the complexity and challenges of integration, a framework termed ‘integrated life cycle framework’ is developed for this thesis, allowing for consistent assessment to understand tradeoffs. This framework can be useful for other transport sectors. The study shows that there is a substantial potential for reducing the environmental impact of shipping through the studied pathways; however, this depends on the carbon intensity of the electricity used in fuel production. Technically, not all fuels are suitable for all vessels. Their suitability is primarily determined by the amount of fuel required for bunkering and the amount of space available onboard. Reduced climate impact comes at the expense of several other impact categories, such as human toxicity, water use, and resource use (minerals and metals). For the same type of fuel, fuel cells have greater impact reduction potential than engine options; however, engines are more cost competitive. Fuel price and utilization rate also influence cost competitiveness. The total life cycle cost of all the studied options is significantly higher than the conventional diesel option, and the critical parameter is the cost of the fuel. The cost of fuel is sensitive to the price of electricity. The carbon abatement cost estimated in this study shows that policies should be designed to imply at least a cost of 250–300 €/tCO2eq for emitting greenhouse gases to make the assessed fuel options cost competitive.
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| 4. |
- Thaler, Bernhard, et al.
(författare)
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Optimal design and operation of maritime energy systems based on renewable methanol and closed carbon cycles
- 2022
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- The phasing out of fossil fuels in the shipping sector is of key importance for reducing greenhouse gas emissions. Synthetic fuels based on renewable energy are a promising option for a sustainable maritime sector, with renewable methanol being one of the most widely considered energy carriers. However, the availability of renewable methanol is still limited and the costs associated with it are significantly higher than for conventional fuels, also because fuel synthesis must rely on carbon dioxide as a resource. Through the use of onboard carbon capture, the release of carbon dioxide during combustion can be avoided, and this closed cycle reduces the need for carbon sources. This paper investigates such a scenario by analyzing overall ship energy systems that use internal combustion engines with connected pre-combustion and post-combustion carbon capture technologies. The effect of these technologies on the techno-economic performance of a fully renewable energy system is investigated by setting up a mixed-integer optimization framework for the optimal design and operation of ship propulsion systems. The propulsion demand for the chosen case study consists of a typical operational profile of a ferry operating in the Baltic Sea. Comparison of the capture cases to a system solely based on renewable methanol reveals significant cost advantages of the closed carbon cycle systems. The baseline scenario has nearly 20% lower annual costs, with total capture rates of 90% in the post-combustion case and around 40% in the pre-combustion case. An extensive sensitivity analysis shows that these cost advantages are robust against various technological and economic boundary conditions. In the pre-combustion case, process heat demand reduction in combination with increased engine heat supply might enable higher capture rates beyond 90%. The results indicate that combining renewable fuels with onboard carbon capture creates opportunities for cost-effective, sustainable shipping.
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| 5. |
- Thollander, Patrik, 1976-, et al.
(författare)
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Energinyckeltal och växthusgasutsläpp baserade på industrins energianvändande processer
- 2021
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Rapport (refereegranskat)abstract
- Svensk industri bör strategiskt arbeta mot ökad energi- och resurseffektivitet på en global marknad med knappare resurser. I detta sammanhang spelar beslutsunderlag och nyckeltal en central roll för att nå ökad effektivitet. Även för tillsynsmyndigheter är rättvisande nyckeltal avseende slutenergianvändning av mycket stor vikt för att kunna bedriva ett rättvist förebyggande och proaktivt arbete med svenska företag. De nyckeltal som finns på internationell och nationell nivå är baserade på tillförd energi och ofta relaterade till en ekonomisk output, till exempel förädlingsvärde. Det saknas emellertid nyckeltal kring slutenergianvändningen inom svensk industri fördelat på energibärare såsom el och olja och fördelat på slutenergiprocesser såsom ugnar, tryckluftskompressorer, etc. De siffror som ibland anges är baserade på grova uppskattningar. Projektets mål har därför varit att generera ett processträd avseende flera av de största, till slutenergianvändning räknat, svenska industribranscherna avseende hur slutenergianvändningen är fördelad på processnivå och olika energibärare, samt att allokera växthusgasutsläpp på dessa olika processer. Resultaten indikerar att nyckeltal baserade på energianvändning och indirekta växthusgasutsläpp på processnivå kan bidra till bättre kunskap om i vilka industriella energianvändande processer den största potentialen för energieffektivisering och minskning av växthusgasutsläpp finns. För att upprätthålla kunskap om var den största potentialen för förbättring finns krävs att energidata regelbundet samlas in efter en standardiserad kategorisering av energianvändande processer. Även om projektet har avgränsats till svensk industri kan resultatet vara till nytta också för andra medlemsstater inom EU liksom globalt.
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