NYK attains AiP for liquefied CO2 carrier design

KNUTSEN NYK Carbon Carriers AS (KNCC), a subsidiary of Japanese shipping line Nippon Yusen Kabushiki Kaisha, has obtained an Approval in Principle from ClassNK for the design of liquified CO2 carriers.

The carriers use the elevated pressure (EP) method to store and transport liquefied carbon dioxide (LCO2) at ambient temperature.

ClassNK reportedly carried out a design review of the ship in accordance with the rules for the survey and construction of steel ships, and has issued an AiP after confirming that the ship meets the prescribed requirements.

The LCO2-EP carrier uses technology developed by KNCC to transport LCO2 in a stable state. Since there is no need to cool LCO2 to cryogenic temperatures, NYK says it is easy to handle and potentially reduces energy and costs during liquefaction.

Moreover, NYK, KNCC, and ENEOS Xplora have developed a Floating Liquefied Storage Unit (FLSU) that combines the LCO2-EP Cargo Tank technology with the Isenthalpic Expansion Cooling & Liquefaction Process, a process which has been researched and developed in collaboration among the three companies.

The shipping line says this FLSU is a pioneering concept that liquefies and temporarily stores CO2 that has been collected and transported as gas in an onshore facility, making it ready for further transport by LCO2 carrier.

“By utilising the features of the EP method, which has the potential to reduce the energy required for liquefaction, and adopting the process, which is expected to be simpler and more compact than conventional cooling methods, it has become possible to install a liquefaction plant on a floating structure,” NYK said in an official release.

Carbon Capture, Utilization and Storage (CCUS) is expected to play a role in achieving a carbon-neutral society, however issues to be addressed include reducing overall costs and securing land for liquefaction and storage facilities.

By utilising this FLSU, NYK says the cost of CO2 liquefaction and the land area required onshore in the CCUS value chain can be reduced, expanding the possibilities for realising CCUS.