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  • Hydrogen
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  • Hydrogen, an Eco-friendly Alternative Energy Source

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.

 

Primary Fuel

Formula

Density [kg/m3]

Energy per mass [kJ/kg]

Energy per vol [GJ/m3]

H2 density [kgH2/m3]

Hydrogen

H2

0.09

141,890

0.013

0.09

LH2

H2

71

141,890

9.9

71

LNG (Methane)

CH4

423

55,530

~ 20.5

106

LPG (Propane)

C3H8

581

50,400

25.2

106

Methanol

CH3OH

793

22,700

18.0

99

MCH

C7H14

862

42,500

26.9

96

Ammonia

NH3

771

22,500

17.4

136

 

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.

 

  • Liquid Hydrogen, LH2

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.

Guide th Selection of Thermal Properties for Cryogenic Insulation Materials
Guide th Selection of Thermal Properties for Cryogenic Insulation Materials
Recently, the demand for cryogenic insulation systems has expanded beyond LNG to cover even lower temperature ranges. Although the IMO initially adopted a resolution aiming to reduce greenhouse gas emissions by 50% by 2050 compared to 2008 levels, with the ultimate goal of achieving zero carbon emissions in the oceans by the end of thecentury, a more ambitious plan targeting a 100% reduction in greenhouse gas emissions by 2050 was announced during the 80th session of the Marine Environment Protection Committee (2023.07.07). This document describes the insulation systems used in current ships for -163°C LNG and -253°C liquefied hydrogen, and analyzes environmental factors influencing the heat transfer mechanisms and other design elements. Through this analysis, the document serves as a technological guide for material selection during the design of insulation systems in cryogenic environments or the development of innovative insulation systems. Ultimately, it aims to offer informa
2024.05.02
Research Report of Material Compatibility for Liquid Hydrogen Storage on Marine Application
Research Report of Material Compatibility for Liquid Hydrogen Storage on Marine Application
Hydrogen is a carbon-free fuel in itself and is used as a raw material for the production of alternative fuels such as ammonia and methanol, which is expected to gradually expand international hydrogen transport and trade. Hydrogen should be treated in the form of liquid hydrogen for efficient storage in hydrogen fueled-ships and hydrogen carrier, but the industry's understanding of the materials used in the liquid hydrogen system and the related material test facility infrastructures are still insufficient. Accordingly, since 2019, the Korean Register has established a test evaluation and analysis infrastructure for eco-friendly alternative fuel ultra-low temperature materials and conducted hydrogen environment simulation tests(ultra-low temperature, hydrogen metal penetration). As a result of this study, this research report establishes an evaluation method for materials such as hydrogen pipes and tanks, and presents standards for materials.
2023.08.09
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