heal.abstract |
The Paris Agreement in 2015 and the subsequent commitments of the signatory states make it clear to the international community the necessity for the immediate implementation of actions to mitigate climate change and adapt to it. Achieving the goals set by the United Nations Framework Convention on Climate Change (UNFCCC) requires a major overhaul of energy, shipping, transport and energy consumption infrastructures, impacting much of human activity and changing consumer behavior worldwide.
The goal of achieving net-zero emissions by 2050, and keeping the average temperature increase below 2Co (Paris Agreement, 2015) or below 1.5Co (IPCC, 2018) relative to pre- -industrial period, has been enhanced by collective global efforts. The World Maritime Organization (IMO) which oversees international shipping, at the recent MEPC80, revised its strategy to reduce greenhouse gas emissions (GHGs), now aiming for net zero emissions from ships by 2050, significantly increasing the level ambition compared to the target of the pre-existing strategy of 2018 where it aimed for a 50% reduction by 2050. At the same time, the revised IMO strategy includes, among other things, intermediate targets of reducing GHG emissions by at least 30% by 2030 and 0% by in 2040, while adjusting the carbon limit per transport job as a global shipping average by at least 40% by 2030, relative to 2008 levels.
In order to achieve these goals, the International Maritime Organization (IMO) has set two technical requirements: the Existing Energy Efficiency Index (EEXI) for the active fleet currently in operation and the Energy Efficiency Design Index (EEDI) for newly built ships. The second piece of legislation focuses on the operational use of the global fleet, using a Carbon Intensity Index (CII) calculated on an annual basis. At the same time, the European Parliament recently approved the proposal to extend the EU Emissions Trading System to include shipping (EU ETS Maritime transport).
The increased pressure to decarbonize the shipping sector, driven by both institutional and market pressures, is creating increasing interest in alternatives, technologies and fuels with low or zero GHG emissions at the lifecycle (Well-to-Wake) level. To explore and establish supply and value chains for alternative marine fuels/technologies, many stakeholders have initiated assessment frameworks and life cycle assessment approaches. In this context, the viability of alternative fuels/technologies is assessed for the medium, micro- and macro-term future, based on various technical and sustainability parameters.
In this work, a multi-criteria decision-making (MCDM) framework is utilized as an effective technique for selecting the appropriate fuel/technology. Various scenarios are evaluated using the VIKOR method to determine the viability of alternative shipping fuels on a medium-long-term basis, using appropriate information to weight the criteria. This paper focuses on three main categories of marine fuels: (1) zero-carbon alternative fuels such as liquefied hydrogen and ammonia, (2) bio-derived fuels such as biodiesel, liquefied biogas/ and bio-methanol and (3 ) to carbon-based synthetic fuels such as methanol and methane. Based on the proposed method, in order to highlight a compromise solution or group of solutions, multi-factorial criteria should be considered, including economic, environmental, safety and social performance. |
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