A phased approach, together with a combination of alternative marine fuels, will be required in the decarbonisation of the global fleet, experts said on the sidelines of the Asia Pacific Maritime (APM) 2024 conference and exhibition in Singapore last week.
"There are quite a few options in the pipeline but each with challenges regarding storage, safety and propulsion technologies," said the director of classification society Bureau Veritas' Innovation Centre of Alternatives and Renewable Energy and its Future Shipping Team, South Asia and Pacific Mike Watt. "One shoe does not fit all and short-range shipping will require different fuels from longer haul journeys."
Fuel availability at ports and the technology that the vessel owners choose are likely to be the deciding factors, he said.
"As no singular alternative fuel can scale to substitute the current [fossil] fuels used, we need to look for synergies to mature the fuels in parallel and vessel operators will need to adopt more flexibility in the fuels' usage," said Denmark's Mærsk Mc-Kinney Moller Centre for Zero Carbon Shipping's chief technology officer (energy and fuels) Torben Norgaard.
Watt also noted that a phased approach is needed by the industry, in line with the approach that think-tanks and non-governmental organisations have taken to concentrate and research on one alternative fuel at a time.
While biofuels looks like the most immediate decarbonisation solution, and equipment manufacturers can provide advice on their use, the shipping industry will face competition from other industries for biofuels uptake, said the programme director of Singapore Nanyang Technological University's (NTU) Maritime Energy and Sustainable Development (MESD) Centre of Excellence Imran Halimi Bin Ibrahim.
Although conversations are still continuing about ammonia's feasibility and safety, Norgaard expects downstream investments around this fuel to pick up at the end of the next 2-3 years. He noted rapid development in ammonia supplies are mainly driven by thermal power plants in Japan, South Korea and Singapore to some degree, expecting supplies of 30mn t of low-emissions ammonia by 2030.
The technology and know-how available about handling ammonia in the chemical industries can then be adapted to a bunkering scenario, Imran said.
"Besides ammonia having no carbon atom, it doesn't have to be stored at such low temperatures compared to LNG or hydrogen." Imran and his team, led by the research lead at NTU's MESD Centre of Excellence Liu Ming, are currently researching on mitigation technologies and environmental impact from ammonia bunkering release when ammonia is used in larger volumes as a shipping fuel. "Currently we've only had ship-to-terminal ammonia transfers. We need to figure out land-to-ship, ship-to-ship, truck-to-ship transfers. The state of ammonia will also influence safety considerations."
Future fuels
Vessels fuelled by LNG could move towards using bio-LNG without extensive modifications, Watt said. Hydrogen fuel cells will be more suited for short voyages. While methanol still has a significant carbon footprint, the industry could eventually progress towards green methanol.
When asked about how the price gap between fossil fuels and transition fuels could be narrowed, Norgaard said that redistributing the risk of upstream investments — which are usually much bigger than those in downstream investments — across the value chain could be the way forward.
"At the investment level, we need to acknowledge a need to join forces on term deals and de-risk competition between the companies," he said.
The biggest thing to watch this year would be the EU's extended coverage of its Emissions Trading System to incorporate the maritime sector, as part of its aim to reach net zero carbon dioxide emissions by 2050, Watt said.
"It will be interesting to see how FuelEU Maritime will be implemented, as it will be the first time market-based measures are being imposed on the marine industry," Norgaard added.
