Knutsen NYK Carbon Carriers (KNCC), a subsidiary of Nippon Yusen Kabushiki Kaisha (NYK Line) and the Knutsen Group, has obtained approval in principle for the design of liquified CO2 carriers that use the elevated pressure method to store and transport liquefied carbon dioxide (LCO2) at ambient temperature.
The tanker will use technology developed by KNCC to transport LCO2 in a stable state. Since there is no need to cool LCO2 to cryogenic temperatures, it is easier to handle and potentially reduces energy and costs during liquefaction.
NYK, KNCC, and Eneos Xplora have also developed an FLSU that combines the above cargo tank technology with an "isenthalpic expansion cooling and liquefaction" (IECL) process.
This FLSU concept will liquefy and temporarily store 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 elevated pressure method, which has the potential to reduce the energy required for liquefaction, and adopting the IECL process, which the companies expect to be simpler and more compact than conventional cooling methods, NYK believes it is possible to install a liquefaction plant on a floating structure.
"By utilising this FLSU, the cost of CO2 liquefaction and the land area required onshore in the [carbon capture] value chain can be reduced, expanding the possibilities for realizing [carbon capture]," said NYK.