NYK has reported an initial onboard methane oxidation rate exceeding 90% during a demonstration test of catalyst equipment for LNG-fuelled marine engines.

The trial is being carried out with Mitsubishi Heavy Industries Marine Machinery & Equipment Co., Ltd., Mitsubishi Shipbuilding Co., Ltd. and Daihatsu Infinearth MFG. Co., Ltd.

A full-scale prototype has been installed on Keys Azalea, an LNG bunkering vessel owned by Keys Bunkering West Japan Co., Ltd. and managed by Taiheiyo Enkai Kisen Co., Ltd., part of the NYK Group.

The bunker tanker supplies LNG fuel to LNG-fuelled ships and operates mainly in the Kyushu and Seto Inland Sea regions. Performance verification will continue under real operating conditions for one year.

NYK noted that methane has a higher global warming potential than carbon dioxide, making slip reduction an important technical issue for maritime decarbonisation.

The catalyst technology is designed to oxidise methane contained in exhaust gas. It combines Mitsubishi Heavy Industries Marine Machinery & Equipment’s catalyst design and manufacturing expertise with Mitsubishi Shipbuilding’s shipbuilding knowledge and Daihatsu Infinearth’s engine optimisation work.

Earlier land-based engine tests confirmed an initial methane oxidation rate of at least 70%. The first onboard measurement on Keys Azalea achieved more than 90% as a standalone exhaust treatment unit.

NYK stated that the demonstration will support the practical application of the technology as it continues work to reduce greenhouse gas emissions from ships and minimise environmental impact.