- Evaluation test to be conducted under actual operational conditions for one year from May
- Methane oxidation rate of 70% or higher was confirmed in the initial performance, contributing significantly to reductions in GHG emissions from marine vessels

TOKYO, May 20, 2025 - (JCN Newswire) - Mitsubishi Heavy Industries Marine Machinery & Equipment Co, Ltd. (MHI-MME) of Mitsubishi Heavy Industries (MHI) Group, have begun demonstration testing for a methane oxidation(Note1) catalyst system for LNG-fueled marine vessels, being jointly developed with Daihatsu Infinearth Mfg. Co., Ltd.

The demonstration test, which began in May this year in cooperation with KEYS Bunkering West Japan Ltd. (KEYS), involves installing the demonstration equipment on the LNG bunkering vessel(Note2) KEYS Azalea, owned and operated by that. KEYS Azalea was built by Mitsubishi Shipbuilding Co., Ltd.

The catalyst system for the demonstration test oxidizes slip methane (unburned methane) contained in the exhaust gas of marine engines. Methane has a high greenhouse effect among GHGs,(Note3) so the ability to suppress its emission is a significant advantage of this system.

The methane oxidation catalyst system was developed with MHI-MME's catalyst design and manufacturing technology at its core, combined with Mitsubishi Shipbuilding's shipboard installation technology, and Daihatsu Infinearth's engine optimization technology. Since an initial methane oxidation rate of 70% or higher has been verified in the onshore engine test, the demonstration testing will be conducted continuously for one year.

MHI Group is making strategic efforts to strengthen its energy transition business. MHI-MME and Mitsubishi Shipbuilding are a part of this strategy, and amid the increasing urgency for global decarbonization, will continue to work to reduce GHG emissions from marine vessels, and contribute to the improvement of the environmental performance of ships on a global scale.

(1) Methane oxidation is a chemical reaction in which methane (CH4) is converted into carbon dioxide (CO2) and water (H2O) through reaction with oxygen.
(2) LNG bunkering vessels are small ships that supply LNG fuel to LNG-fueled vessels.
(3) Greenhouse gases (GHGs) include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The catalyst system for this demonstration test will only target slip methane.

About MHI Group

Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit www.mhi.com or follow our insights and stories on spectra.mhi.com.

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