ClassNK has issued an Approval in Principle (AiP) for an Onboard Carbon Capture and Storage (OCCS) system developed by Mitsubishi Shipbuilding on 10 April 2025, according to the company's release.
The certification confirms the system’s compliance with regulatory and safety requirements. The shipping industry is seeing increased interest in CO2 capture from exhaust gases as a method to reduce greenhouse gas (GHG) emissions, alongside efforts in fuel conversion. To address this, development of onboard CO2 capture and storage systems is advancing.
ClassNK has introduced the "Guidelines for Shipboard CO2 Capture and Storage Systems" under its Transition Support Services to facilitate the development and implementation of such technologies. These guidelines specify safety requirements for OCCS and its installation on vessels.
ClassNK conducted a review of Mitsubishi Shipbuilding’s OCCS design based on the "Guidelines for Shipboard CO2 Capture and Storage Systems". Following confirmation of compliance with the outlined requirements, the AiP was issued.
An Approval in Principle (AiP) is issued at the initial design stage or before a specific target ship is selected. The design is assessed against existing regulations, including international conventions and ship classification rules, to confirm conformity. The AiP reduces the need for regulatory rework later, shortens class registration examination time, and serves as a technical foundation for external validation of the design.
Founded in 1899, ClassNK is a Japanese classification society headquartered in Tokyo. It provides ship classification, certification, and technical services to ensure safety and environmental compliance in the maritime industry. ClassNK is one of the world’s leading classification societies, overseeing a significant portion of the global merchant fleet.
Mitsubishi Shipbuilding is a subsidiary of Mitsubishi Heavy Industries (MHI) Group, based in Yokohama, Japan. Established as part of MHI’s maritime division, it focuses on designing and constructing ships, including advanced vessels for commercial and environmental purposes.