Japanese develop system to slash methane slip on LNG-fuelled vessels

In a potential big breakthrough on shipping’s path to decarbonisation, the Japanese look like they have minimised the issue of methane slip for ships using LNG as a fuel.

Hitachi Zosen, Mitsui OSK Lines (MOL) and Yanmar Power Technologies have received approval in principle from ClassNK for a methane oxidation catalyst system, which could cut methane slip from ships by more than 70%. The system reduces methane slip by placing a methane oxidation catalyst in an LNG fuel engine and oxidising the methane. This is the first time in the world that a methane oxidation catalyst system has received approval in principle.

Hitachi Zosen and Yanmar created the system design with MOL and Namura Shipbuilding set to build the actual demonstration vessel and design the system’s installation. The proposed system meets the requirements of the International Code of Safety for Ship Using Gases or Other Low-flashpoint Fuels (IGF Code) and other regulations.

This system is placed in the exhaust pipes of LNG fuel engines and generators that contain unburned methane, and methane is oxidised on the catalysts to reduce methane slip.

More than one third of all ships under construction today are for vessels that will use LNG as a fuel, something that has alarmed environmentalists over the methane slip issue.

Methane, according to the Intergovernmental Panel on Climate Change (IPCC), accounts for about a quarter of all the heat trapped in the atmosphere since the pre-industrial era.

In August last year the IPCC released a significant report in which for the first time it took aim at methane, something that is emitted from LNG-powered vessels and by energy majors in creating LNG.

According to the IPCC, around 0.3C of the 1.1C that the world has already warmed by comes from methane.

In April last year the World Bank issued a report on decarbonising maritime transport in which it specifically recommended countries pull back from investing in further LNG bunkering infrastructure.

Taking a swipe at LNG as a fuel, the bank recommended that countries should avoid new public policy that supports LNG as a bunker fuel, reconsider existing policy support, and continue to regulate methane emissions.

Sam Chambers

Starting out with the Informa Group in 2000 in Hong Kong, Sam Chambers became editor of Maritime Asia magazine as well as East Asia Editor for the world’s oldest newspaper, Lloyd’s List. In 2005 he pursued a freelance career and wrote for a variety of titles including taking on the role of Asia Editor at Seatrade magazine and China correspondent for Supply Chain Asia. His work has also appeared in The Economist, The New York Times, The Sunday Times and The International Herald Tribune.


  1. The drawing of the vessel looks as if it has experienced a catastrophic explosion in the superstructure. I hop this is not an unfortunate omen

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