MOL receives AiP for ammonia FSRU design from ClassNK

Japanese shipping company Mitsui O.S.K. Lines (MOL) has received approval in principle (AiP) from classification society ClassNK for the design of a floating storage and regasification unit (FSRU) for ammonia.

Illustration; Credit: MOL

As informed, the vessel design was jointly developed by MOL and Mitsubishi Shipbuilding Co., a subsidiary of Mitsubishi Heavy Industry (MHI) Group.

ClassNK carried out a review of a conceptual design of the Ammonia FSRU based on its Part N of Rules for the Survey and Construction of Steel Ships for ships carrying liquefied gases in bulk, “Guidelines for Floating Offshore Facilities for LNG/LPG Production, Storage, Offloading and Regasification” and the other relevant rules.

The classification society examined risk assessment taking into account the results of the gas dispersion study. Upon confirming it complies with the prescribed requirements, ClassNK issued the AiP.


Last February, MOL completed a concept study on ammonia FSRU. In applying for this AiP, MOL, along with ClassNK and Mitsubishi Shipbuilding, conducted a hazard identification study (HAZID), and identified hazards and their risks to be considered in the design of the ammonia FSRU.

Before the HAZID, MOL conducted a gas dispersion study. The result of the gas dispersion study was used in the HAZID, which allowed the HAZID team to evaluate risks more quantitatively and narrow down specific preventive measures and countermeasures against ammonia leaks. The company plas to use this knowledge to further pursue the business development of ammonia FSRUs.

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FSRU is a floating facility designed for liquified gases and equipped with storage tanks and a regasification facility that receives liquified gas at sea, vaporizes it and sends it ashore. It enables a large scale of storage and distribution of seaborn ammonia.

By introducing the ammonia FSRU concept, MOL expects to contribute to developing the ammonia value chain as an alternative carbon-neutral fuel.

Ammonia, which does not emit CO2 during combustion, is projected to be widely used as a source of clean energy for decarbonization, while the development of onshore facilities for storage and regasification is a challenge.

Recently, the shipping firm kicked off a feasibility study on establishing a clean hydrogen and ammonia value chain derived from renewable energy sources in Thailand. The project is being conducted in collaboration with Electricity Generation Authority of Thailand (EGAT), Mitsubishi Company, and Chiyoda Corporation.

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MOL Group has set a mid-to-long-term target of “achieving net zero greenhouse gas (GHG) emissions by 2050 with the concerted effort throughout the Group”