LEE- Deniz Ulaştırma Mühendisliği Lisansüstü Programı

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http://hdl.handle.net/11527/19250

Gözat

Konu "Alternative fuels" ile LEE- Deniz Ulaştırma Mühendisliği Lisansüstü Programı'a göz atma
  • Öge
    Decarbonization pathways in maritime transportation: A techno-economic analysis of alternative marine fuels
    (Graduate School, 2024-10-11) Ejder, Emir ; Arslanoğlu, Yasin ; 512202006 ; Maritime Transportation Engineering
    The doctoral thesis addresses the decarbonization challenge that the maritime transport sector, a key player in global trade, is confronting in the context of climate change, one of the most pressing environmental challenges of the 21st century. By thoroughly examining the potential of alternative fuels and emission reduction technologies in their technical, economic and environmental dimensions, the study provides a comprehensive and robust analytical framework for the sector's transition to a sustainable future. The research's theoretical foundation is based on sustainable transition theory, a socio-technical systems approach, and technological innovation systems literature. This theoretical framework allows us to conceptualize the decarbonization of the maritime transport sector not only as a technological issue but also as a system transformation involving complex socio-economic and political dynamics. From a methodological perspective, the study adopts a mixed research design involving a sophisticated combination of qualitative and quantitative methods. The approach allows us to address the research topic's multidimensional nature comprehensively. The study examines different aspects of the decarbonization process of the maritime transport sector through three interrelated original papers. The first paper deals with the use of ammonia-fueled engines on bulk carriers. In this study, a techno-economic analysis method supported by Monte Carlo simulation is used. The analysis also takes into account regulatory frameworks such as the recently introduced Energy Efficiency Existing Ship Index (EEXI) and Carbon Intensity Indicator (CII) of the International Maritime Organization (IMO). This approach allowed us to assess the potential and limitations of ammonia within the current regulatory context. The second paper presents a comparative cost-benefit analysis of various emission reduction techniques for container ships. Nine different scenarios are analyzed, revealing the economic and environmental impacts of scrubber systems, LNG, ammonia, and other alternative fuels. The study contributes to the literature, especially examining the technological and economic trade-offs between retrofitting the existing fleet and new building ships. The third paper's empirical analysis of LNG and dual-fuel engines, based on real-world data from 11 sea voyages over a three-year period, provides valuable insights. The use of the decision tree method in this study not only reveals the potential of LNG in the context of IMO's 2050 emission targets but also highlights the practical limitations of this technology, thereby offering actionable guidance for industry professionals. The study's findings show that alternative fuels and emission reduction technologies have significant potential for decarbonizing the maritime transport sector. However, realizing this potential requires overcoming various technical, economic and operational challenges. For example, while using ammonia reduces total fuel consumption and effectively reduces NOX emissions compared to VLSFO and MGO, it also has disadvantages such as low energy density and high production costs. Similarly, while using LNG reduces about 30 per cent of CO2 emissions, it faces problems such as the problem of methane leakage and the inability to meet the IMO's 2050 targets fully. One of the study's most important conclusions is that there is no single universal solution for the sector's decarbonization. The effectiveness of emission reduction technologies varies depending on ship type, operational profile, economic factors, and even geographical region. This underscores the need for multifaceted and adaptive strategies, providing a sense of reassurance about the sector's flexibility and resilience in the face of decarbonization challenges. The research also illuminates the complex relationships at the intersection of technological innovation, economic feasibility, and regulatory frameworks. For example, IMO regulations such as EEXI and CII significantly influence the technology choices of ship owners and operators. It shows that the sector's decarbonization process is a technological issue and a complex socio-technical transition process with institutional, economic, and political dimensions. The thesis findings highlight that the sector's decarbonization should be gradual. In the short term, measures to improve the energy efficiency of the existing fleet (e.g. operational optimization, hull and propeller upgrades) will be important. In contrast, in the medium term, the role of transition fuels such as LNG will increase. In the long term, a transition to zero-emission fuels such as ammonia and hydrogen seems inevitable. The success of this transition process depends on the cooperation of all sector stakeholders and the development of holistic policies. The study also highlights the critical role of decarbonization of the maritime transport sector in the fight against global climate change. The target of the Initial GHG Strategy adopted by IMO in 2018 to eliminate the total annual GHG emissions of the sector by 2050 is very ambitious. The realization of this target requires not only technological innovations but also fundamental changes in the sector's business models, operational practices and regulatory framework. Another important finding of the research is the multidimensional nature of the barriers to the adoption of alternative fuels and emission-reduction technologies. Technical challenges (e.g. lack of fuel infrastructure, required changes in ship designs), economic barriers (high initial costs, uncertain return on investment), and institutional barriers (regulatory uncertainties, lack of industry standards) complicate this transition process. To overcome these barriers, it's crucial for public-private partnerships to be strengthened, making the audience feel involved in the sector's transition. The study also addresses the potential impacts of decarbonization of the maritime transport sector on global supply chains. The transition to alternative fuels will require restructuring fuel supply chains, which may affect global trade flows. For example, the widespread use of fuels such as LNG or ammonia will require new infrastructure investments for production, storage and distribution. It may increase the strategic importance of some ports and regions while reducing the competitiveness of others. Another significant contribution of the thesis is its analysis of the financing of the decarbonization of the maritime transport sector. The study reveals that more than traditional financing models may be needed to support the sector's long-term and costly transformation. In this context, the potential of innovative financing mechanisms such as green bonds, carbon credits and sustainability-linked loans is highlighted. In conclusion, this PhD thesis provides a comprehensive analytical framework for the transition of the maritime transport sector towards a sustainable future. The study emphasizes the need for a multifaceted approach to reducing the sector's carbon footprint while also highlighting the challenges and opportunities that may be encountered in this process. In this context, it is concluded that technological innovations, economic incentives, regulatory frameworks, and sectoral cooperation need to be addressed in an integrated manner. This research provides valuable insights for policymakers, industry leaders, and academics and a solid theoretical and empirical foundation for future research. However, the study also has some limitations. In particular, the limited number of vessel types and operation profiles examined may affect the generalizability of the findings. Moreover, the rapidly evolving technological and regulatory environment may necessitate updating the study's findings. For future research, it is important to extend and deepen the scope of this study. Examining a wider range of ship types and operational profiles will increase the generalizability of the findings. However, a more in-depth examination of the effects of global supply chains and geopolitical factors on alternative fuel adoption to understand the long-term impacts of alternative fuels and emission reduction technologies could enrich the body of knowledge in this field. Decarbonization of the maritime transport sector is critical not only for the sector itself but also for the global climate change response. This thesis aims to contribute to the sector's transition to a sustainable future by presenting the strategic approaches necessary to tackle this complex and multidimensional challenge. The successful transformation of the sector will be possible through coordinated efforts by all stakeholders, continuous innovation, and long-term, stable policy frameworks.