Risk Assessment of Liquid Hydrogen in Marine Transportation

This paper presents the major steps of the risk assessment methodology for liquid hydrogen bunkering and a preliminary assessment of safety distances. European and international shipping regulations are becoming increasingly strict to contribute to a neutral climate where Sulfur and Nitrogen Oxides, Carbon Dioxide, and greenhouse gas emissions will be considerably reduced (European Commission, 2019; ΙΜΟ, 2008). New technologies to adopt alternative low-flashpoint fuels have been already considered to reduce such hazardous emissions from ships, including low-carbon fuels such as Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG) and methanol. However, the use of such fuels can benefit in the mid-term applying the existing technologies and infrastructure. One long-term solution, among others, that would enable a zero-carbon shipping industry in the future is hydrogen. IMO, through the IGF code, allows the application of hydrogen as an alternative fuel for ships (IMO, 2015) and the vessels that use hydrogen as a fuel shall be designed with the specific requirements contained in the SOLAS alternative ship design regulation (IMO, 2009). In addition, some guides have already been developed by classification societies encouraging the use of LH2 (DNV, 2021a; IMO, 2021; ABS, 2021). In parallel, recommendations for ships carrying hydrogen as a cargo have been developed (IMO, 2016; ClassNK, 2017). Infrastructure for transport, storage and bunkering still needs to be built and new safety regulations should be developed and implemented for the use of hydrogen as a marine fuel.