Classification societies ClassNK and the American Bureau of Shipping (ABS) have issued approvals in principle (AiPs) for the design concept of 23,000 cbm and 50,000 cbm large liquefied CO2 (LCO2) carriers.
As disclosed, the design was developed by Japanese companies Nippon Yusen Kabushiki Kaisha (NYK Line), Kawasaki Kisen Kaisha (K Line), Mitsui O.S.K. Lines (MOL), and Nihon Shipyard, a joint venture for ship design and sales between Imabari Shipbuilding and Japan Marine United Corporation. Compatriot companies Mitsui & Co., Mitsubishi Corporation and Mitsubishi Shipbuilding, a part of Mitsubishi Heavy Industries (MHI) Group, also worked on the design.
Approvals in principle, which were granted during Gastech 2024, indicate that the certification bodies have reviewed the basic design and approved it as satisfying the technical requirements and safety criteria. The assessment was conducted in accordance with the IGC Code and ABS and ClassNK classification rules applicable to vessels transporting liquefied gas in bulk.
The two LCO2 carriers that received AiP certifications are low-pressure type 50,000 cbm and 23,000 cbm vessels developed for long-distance ocean voyages.
The AiP certifications assume the use of appropriate cargo tank material as a replacement for the nickel steel previously considered. Additionally, post-welding heat treatment (PWHT), one of critical issues in establishing cargo tank manufacturing, may be omitted by the Engineering Critical Assessment (ECA) approach,
NYK believes that the establishment of CO2 transport technology by large vessels will greatly contribute to the realization of a carbon-neutral society.
Demand for LCO2 carriers is expected to grow in tandem with various carbon capture and storage (CCS) projects involving the transportation of C02 captured in Japan to storage sites located oversea.
Recently, Mitsubishi Shipbuilding, Nihon Shipyard, Mitsui & Co. and Mitsubishi Corporation have collaborated to achieve standardization of LCO2 carriers suited for use by multiple projects.
The partners want to establish a supply chain in order to build LCO2 carriers consistently within Japan, which would contribute towards the realization and improvement of the economic efficiency of CCS value chains.
These initiatives have led to the acquisitions of two AiPs in collaboration with three major Japanese shipping companies K Line, MOL and NYK Line.