The adoption of hydrogen as marine fuel for deep sea-going vessels seems to be lagging behind its counterparts such as methanol and ammonia.
Hydrogen is an attractive fuel for internal combustion engines and its combustion produces no greenhouse gas emissions. However, hydrogen needs to be compressed (700 bar) or liquified (-253 °C), which requires substantial ingenuity from the engineering side so as to enable a vessel to store the chemical element safely at such low temperatures while keeping the structural integrity of the tanks and the entire vessel intact.
The key hurdles hindering a greater uptake are hydrogen’s low energy density and the corresponding space demands, heralding a limited hydrogen uptake in deep-sea ship segments where 2-stroke engines are a natural choice for propulsion, DNV said in its Maritime Forecast to 2050 report. The publication considers the comprehensive production, distribution, and bunkering infrastructures required to enable the maritime industry’s shift to carbon-neutral fuels. It also gives an outlook on regulations, drivers, future technologies, and costs for decarbonizing shipping.
On the other hand, hydrogen is expected to be a more viable option for the short-sea segment, as major engine manufacturers, such as MAN Energy Solutions and Wärtsilä, are experimenting with blend-in technologies mixing hydrogen with other fuels to improve the performance of 4-stroke engines.
“Short-sea shipping is expected to be instrumental for maturing hydrogen technology. Consequently, the development of fuel cells and 4-stroke engines is ahead of other hydrogen energy converters,” the report said. “The current technology readiness levels of methanol fuel technologies are higher than for ammonia and hydrogen.”
According to the report, ammonia and hydrogen onboard fuel technologies will be available in three to eight years. At the moment, LNG as a fuel is dominating the orderbook of larger ships and hybrid solutions featuring batteries are prevalent on smaller vessels.
Of the 1,046 ships on order with alternative fuels, 167 are LNG-fuelled LNG carriers; 367 are LNG-fuelled ships of other types; and 417 are using battery/hybrid propulsion.
Methanol had previously been a choice exclusively for tankers in the methanol trade, with 11 ships in operation and 14 new tankers on order. This year we also see uptake in the container segment, with 21 ships on order with methanol as fuel. 76 LPG carriers using LPG as fuel are either in operation or on order, data from DNV shows.
There have been some notable developments in the short-sea space with the first hydrogen-powered newbuilds being ordered. The world’s first hydrogen-powered cargo ship (With Orca) and the first hydrogen-powered tug (Hydrotug), using 4-stroke engines are scheduled to be put into operation within the next couple of years.
With Orca, a self-unloading bulk carrier will be powered by hydrogen, stored onboard in compressed form, and the hydrogen combustion engine will be optimised for increased efficiency. The vessel will also have a fuel cell system for energy production in low load conditions. A significant part of the energy required to operate the 88 m/5,500 tonne vessel will be harvested directly from the wind through two large rotor sails. The vessel also has the ability to store excess energy in batteries. The zero-emission ship is scheduled to enter operation in early 2024.
Scheduled to become operational in the first quarter of 2023, the Hydrotug is said to be an important step for the Port of Antwerp-Bruges in the transition to a sustainable, climate-neutral port by 2050. The tug consists of two BeHydro V12 dual fuel medium speed engines that can run on hydrogen or traditional fuel.
BeHydro, a joint venture between CMB.TECH and ABC, recently developed the technology for medium-speed engines with higher power output. The Hydrotug is the first vessel to be powered by these dual fuel medium speed engines – each providing 2 megawatts – with the latest EU Stage V emissions after treatment.
Finally, the world’s first liquid hydrogen-powered ferry MF Hydra was delivered to its owner Norwegian ferry operator Norled earlier this year. Ballard Power Systems delivered two fuel cell modules (total capacity 400 kW) to the ferry.
DNV warned that using new fuels and fuel technologies will require all maritime industry stakeholders to focus increasingly on safety, including the development and implementation of safety regulations. This in particular relates to addressing the toxicity of methanol and ammonia, and the extreme flammability of hydrogen.
“From a regulatory point of view methanol gained an advantage over ammonia and hydrogen in December 2020 when the IMO approved the interim guidelines for the Safety of Ships Using Methyl/Ethyl Alcohol as Fuel. If agreed with the Flag Administration, these guidelines can be used in lieu of the risk-based alternative design process for methanol-fuelled ships. No such international standard is currently in place for ammonia or hydrogen, but the development of guidelines for these fuels is included on the IMO’s already extensive work plan related to alternative fuels,” the report said. “Given the typical timeline for development of safety regulations in the IMO, it is likely that the first ships applying ammonia or hydrogen as fuels will be built without the support of existing detailed statutory regulations.”
Until alternative fuels become more readily and widely available, there is a renewed interest in using carbon capture and storage onboard ships with conventional fossil fuels.
More demonstration and pilot projects will be needed to enhance the technology readiness of onboard CCS, and there are several ongoing R&D projects that address barriers to implementation, the report indicates.
The industry is pushing forward with studies of CCS potential on board ships, and developing large liquified CO2 carriers as the key part of the CCS value chain. Some of the most recent developments will see Value Maritime’s CCS system tested on board Eastern Pacific Shipping’s (EPS) MR tankers