WAFP - Energy Transition at Maritime and Ports

Adopting renewable fuels has a good potential to address the environmental impact and fossil fuel dependency of maritime transport. E-ammonia, bio-methanol, and bio-diesel are among the promising options. This study evaluates these fuels for dry bulk shipping using insights from expert interviews and multi-criteria decision analysis (MCDA), considering factors like environmental impact, economic viability, technical feasibility, and regulatory support. The findings suggest that bio-diesel emerges as the most viable short-term solution due to its technical maturity and cost-effectiveness. E-ammonia, despite its strong greenhouse gas reduction potential, faces significant technical and economic challenges, ranking lowest among the options. However, with advancements in technology and infrastructure, e-ammonia and bio-methanol may offer promising opportunities in the long term.

The shipping industry accounts for 2.89% of global greenhouse gas (GHG) emissions, prompting the International Maritime Organization (IMO) to establish ambitious decarbonization goals, including net-zero GHG emissions by around 2050. A key strategy to achieve this is the adoption of alternative marine fuels. This study evaluates ammonia, hydrogen, methanol, and biofuels, assessing their potential to meet IMO targets. Key factors such as energy density, scalability, cost, infrastructure requirements, environmental impact, and vessel type adaptability are analyzed. Ammonia, with carbon-free emissions and efficient storage, is suitable for large vessels like tankers and bulk carriers, but toxicity and combustion efficiency pose challenges. Hydrogen, with high energy content, is promising for short-sea shipping and ferries but requires significant infrastructure investments. Methanol, widely adopted, is suitable for retrofitted and newbuild ships, while biofuels, though versatile, face scalability and feedstock limitations. Among these, liquid hydrogen (LH2) emerges as a leading candidate for maritime decarbonization. However, overcoming its lower volumetric energy density necessitates advancements in vessel design and operational profiles to fully realize its potential as a sustainable energy source. This study highlights the need for tailored strategies to align fuel adoption with ship types and operational requirements.

The indispensable role of the maritime sector in facilitating global trade underscores the imperative for sustainable advancements. The future trajectory of decarbonization hinges upon the innovation of novel technologies and the adoption of alternative fuels, with hydrogen emerging as a promising solution. Despite the prevalent focus on hydrogen fuel cells (H2FC) in research, the potential of hydrogen internal combustion engines (H2ICE) remains relatively unexplored. This study endeavors to conduct a comparative life cycle assessment of the H2ICE, H2FC, and diesel engine of a passenger vessel. The findings demonstrate that both hydrogen-powered systems exhibit notable environmental superiority compared to diesel engines, yielding substantial reductions in Global Warming Potential (84-87%). Furthermore, H2ICE presents advantages over H2FC regarding Global Warming Potential and Abiotic Depletion Potential (elements and fossil). This study advocates for a broader exploration of ship hydrogen-powered systems and their potential applications in the shipping industry, recognizing the promise of the H2ICE.