Hydrogen as a Maritime Fuel–Can Experiences with LNG Be Transferred to Hydrogen Systems?

Abstract

As the use of fossil fuels becomes more and more restricted there is a need for alternative fuels also at sea. For short sea distance travel purposes, batteries may be a solution. However, for longer distances, when there is no possibility of recharging at sea, batteries do not have sufficient capacity yet. Several projects have demonstrated the use of compressed hydrogen (CH2) as a fuel for road transport. The experience with hydrogen as a maritime fuel is very limited. In this paper, the similarities and differences between liquefied hydrogen (LH2) and liquefied natural gas (LNG) as a maritime fuel will be discussed based on literature data of their properties and our system knowledge. The advantages and disadvantages of the two fuels will be examined with respect to use as a maritime fuel. Our objective is to discuss if and how hydrogen could replace fossil fuels on long distance sea voyages. Due to the low temperature of LH2 and wide flammability range in air these systems have more challenges related to storage and processing onboard than LNG. These factors result in higher investment costs. All this may also imply challenges for the LH2 supply chain.

The decarbonisation of the maritime sector: Horizon 2050

“…At this point, it is necessary to compare methane with hydrogen to assess the viability of one versus the other [79]. Two elements are key: the flammability range of hydrogen is 4-74% by volume, well below that of methane, which is 5-15%, and hydrogen has a lower ignition energy of 0.02 MJ compared to 0.28 MJ for methane [80].…”

“…Thus, the temperature of liquefied hydrogen at atmospheric pressure is 90 °C lower than that of LNG [85]. This means that the fuel service system will be subject to strong thermal variations, even greater than those of an LNG system, reaching variations of around 270 ºC, when in an LNG system it is around 180ºC [79]. Likewise, the low storage temperatures of hydrogen in its liquefied state give rise to specific storage materials, with the consequent higher investment [86].…”

“…Another fact to take into account in the hydrogen storage chain is that hydrogen is only liquid between -240ºC and -253ºC, which will require highly advanced systems to avoid heating of the charge both through heat transfer during storage and during loading/unloading operations, if these have to be carried out, as well as for the type of molecule it is in (ortho or parahydrogen) [79], and during loading/unloading operations if these have to be carried out, as well as for the type of molecule in which it is found (ortho or parahydrogen) [79], which would cause problems in the management of the boil-off gas (BOG) generated during storage in the tanks.…”

Low carbon transportation fuels: deployment pathways, opportunities and challenges

“…22 Of these fuels, ammonia and methanol are often cited as leading contenders. [159][160][161][162][163] Ammonia offers several advantages over hydrogen, such as its higher volumetric energy density and avoiding the need for cryogenic fuel storage. However, ammonia is highly corrosive and toxic, making it more challenging to handle.…”

Superconductivity and Hydrogen Economy: A Roadmap to Synergy

“…In transportation, batteries as storage of electricity might be a proper option for a short distance, but they do not have enough capacity for long journeys. Due to higher energy density in hydrogen fuel cells, they can replace batteries in the storage of energy [19,29]. Norway projects that, in 2030, about 23% of total hydrogen in the country would be consumed in the transportation sector [4], where relevant industries can implement hydrogen fuel cells.…”