The use of hydrogen fuel in ships is an environmentally friendly and sustainable green solution. Unlike carbon-based fuels that emit air pollutants such as CO2, NOx, and SOx, hydrogen is an eco-friendly energy source that does not emit air pollutants.

In addition, hydrogen fuel also has high efficiency, therefore, it can be used as the most suitable energy source for electric propulsion. Also, it has high energy density, so it can be an alternative to the short-range problem of battery-driven ships.

However, hydrogen application for ships has several challenges. The biggest challenge is its production and storage. Since hydrogen is an extremely light gas, it requires very high pressure (700 bar) or very-low temperature (-253 °C) to store it.

Hydrogen can be classified into various colors depending on its production method such as green (renewable energy), blue (LNG reforming + carbon capture), and pink (nuclear energy) hydrogen. In order to realize the global de-carbonization target, the proportion of green hydrogen is expected to increase.

Hydrogen is liquefied at -253°C and 1 atm, and its volume is reduced to 1/845 of that of gaseous hydrogen. This liquid hydrogen is transparent, colorless, and non-corrosive. For the LH₂, the Ortho-Para hydrogen conversion has to be taken into account.

When room temperature hydrogen (Ortho hydrogen:Para hydrogen = 75%:25%) is converted into a liquid at -253℃ in a liquefaction facility and then stored in a tank, Ortho hydrogen is gradually converted to Para hydrogen and the LH₂ evaporates the conversion heat (527J/g) greater than the latent heat (445.6J/g). This conversion heat gradually evaporates the LH₂ in the storage tank and changes it to a gaseous state. Therefore, the Ortho hydrogen must be converted to Para hydrogen.

In 2020, Korea Shipbuilding & Marine Engineering and Hyundai Mipo Dockyard obtained the Approval in Principle (AiP) for the world's first commercial LH₂ carrier (20k class) from our KR, and are pursuing technology development for the goal of its commercialization in 2030. In addition, once the infrastructure such as the LH₂ import base and export terminal is established and the economic feasibility of LH₂ is secured, demands for LH₂ carriers are expected to increase.

At the MSC 94th in 2014, Japan and Australia pointed out that the IGC Code did not include the requirements for the safe transportation of liquefied hydrogen, and proposed discussion on hydrogen transportation regulations to strengthen safety requirements.

The review of regulations on hydrogen transportation, which began discussions at the CCC 2nd in 2015, was adopted at the MSC 7th in 2016, with the adoption of the 'Interim Recommendations for Carriage of Liquefied Hydrogen in Bulk (Resolution MSC.420(97)) – (adopted on 25 Nov. 2016).' And in 2021, it was applied to the ‘Suiso Frontier (the world's first liquefied hydrogen carrier)’ which is a test vessel for transporting LH₂ between Australia and Japan.

The LH₂ transportation regulations currently under development are as follows.

• ∙ CCC 8^th (2022)
  • Proposed a new concept of independent cargo hold in which insulation materials such as polyurethane foam and hydrogen gas are used for the inner insulation layer.
• ∙ CCC 9^th (2023, planned)
  • Draft guidelines for the transportation of liquefied hydrogen including a new concept of independent cargo hold are to be submitted.
• ∙ CCC 10^th (2024, planned)
  • Membrane-type liquefied hydrogen cargo hold will be discussed additionally at CCC 10th.

In line with the national policy of importing hydrogen from abroad, KR began developing LH₂ carrier technology for the first time in South Korea in 2016. Since then, we have been working together with domestic shipyards, research institutes, and ship design companies to develop related technologies for the goal of demonstration by 2030.

Since then, with the support of the Ministry of Trade, Industry and Energy, we are developing the core systems of liquid hydrogen carriers, such as the cargo hold, loading/unloading, and BOG handling systems. Also, with the support of the Ministry of Oceans and Fisheries, we are developing safety standards for liquid hydrogen carriers.

In addition, in order to commercialize liquid hydrogen carriers and secure domestic technology, we have established a technology roadmap for test demonstration vessels, land testbeds, and cryogenic equipment R&D.

Our KR develops standards or guidelines for liquid hydrogen carriers and fuel cell systems for ships.

For the development of technologies and regulations related to liquid hydrogen carriers, our KR is making great efforts to advance technologies through collaboration with domestic shipyards, equipment companies, and research institutes.