Tokyo, Japan | October 7, 2025 – In a landmark achievement for the maritime industry and global decarbonization efforts, Mitsui O.S.K. Lines, Ltd. (MOL), Kanadevia Corporation, and Yanmar Power Solutions Co., Ltd. have successfully achieved a methane slip reduction rate of 98% in onboard trials of LNG-fueled vessels. The results mark a major technological breakthrough, surpassing the initial target of 70% and signaling a transformative step toward sustainable shipping.
The trials are part of a six-year initiative under the Green Innovation Fund Project, titled “Development of Methane Slip Reduction Technology for LNG-Fueled Vessels through Catalyst and Engine Improvements”, funded by the New Energy and Industrial Technology Development Organization (NEDO).
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Unprecedented Methane Slip Reduction at Sea
Since May 2025, full-scale demonstration voyages have been underway aboard the LNG-powered large coal carrier REIMEI, operated by MOL. These voyages cover international shipping routes, including those between Japan and Australia. Operating under real-world maritime conditions—where variables such as sea states, load fluctuations, and environmental factors present unique challenges—the onboard methane slip reduction system delivered remarkable performance.
The system, which integrates a methane oxidation catalyst and an Exhaust Gas Recirculation (EGR) system, achieved a 98% methane slip reduction rate at 75% engine load—a typical operating condition for long-haul voyages. This outcome not only exceeded expectations but also surpassed results recorded during prior land-based trials, which reached a peak reduction of 93.8% at full engine load.
“Achieving a 98% reduction under real onboard conditions demonstrates the maturity of this technology and its readiness for real-world application,” shared Consortium. “This is a pivotal moment for the future of LNG as a viable low-emission marine fuel.”
A First in Maritime – Global Leadership in GHG Reduction
This project is the first of its kind globally to realize methane slip reduction at such scale onboard a vessel. While the issue of methane emissions from LNG-fueled engines remains a concern in both maritime and terrestrial applications, no commercial solution had previously achieved this level of effectiveness—particularly under the demanding conditions of sea operations.
Methane, a potent greenhouse gas with a global warming potential over 25 times greater than CO₂, is often emitted unburned from dual-fuel marine engines, a phenomenon known as methane slip. Addressing this challenge is critical to ensuring that LNG remains a credible transitional fuel on the path toward net-zero emissions in maritime transport.
Technological Backbone: Catalyst Innovation & Engine Optimization
The heart of the methane slip mitigation system lies in its innovative methane oxidation catalyst layer, integrated with a highly tuned EGR system. Together, these components significantly reduce unburned methane in the exhaust gases by enhancing combustion efficiency and facilitating post-combustion oxidation of methane.
Following the successful land-based validation—certified by Nippon Kaiji Kyokai (ClassNK)—the project team adapted and miniaturized the system for marine deployment, incorporating design enhancements to withstand the variable temperatures, vibrations, and humidity levels inherent to shipboard environments.
Next Steps: Continued Trials and Roadmap to Social Implementation
Onboard validation trials will continue through FY2026, with ongoing assessments focused on catalyst durability, long-term system reliability, and maintenance cycles. The goal is to establish a commercially viable system that can be widely implemented across LNG-fueled fleets from FY2027 onward.
This initiative is not only aimed at MOL’s own decarbonization strategy but is also intended to serve as a template for global adoption across the maritime industry, potentially setting a new international standard for methane emissions control.
Collaborative Effort Under Green Innovation Fund
The methane slip reduction project is being executed as part of the Green Innovation Fund initiative, a Japanese government-backed program to accelerate decarbonization across critical industrial sectors. The project is managed by Kanadevia Corporation, in joint execution with MOL and Yanmar Power Solutions.
Project Overview:
- Project Sponsor: New Energy and Industrial Technology Development Organization (NEDO)
- Project Name: Green Innovation Fund Project “Development of Next Generation Ships”
- Implementation Period: FY2021 – FY2026 (planned)
- Managing Company: Kanadevia Corporation (President & CEO: Michi Kuwahara)
- Joint Executors:
- Mitsui O.S.K. Lines, Ltd. (President: Takeshi Hashimoto)
- Yanmar Power Solutions Co., Ltd. (President & CEO: Masaru Hirose)
- Research Theme: Development of Methane Slip Reduction Technology from LNG-Fueled Vessels by Catalyst and Engine Modification
Industry Impact and Future Outlook
By proving the feasibility of ultra-low methane slip emissions from LNG-fueled vessels, this project could play a pivotal role in accelerating the maritime industry’s shift to cleaner fuels. The implications for global climate targets are significant, especially as regulatory pressure mounts from the IMO and other international bodies.
“We are proud to be leading this critical innovation,” shared Yanmar Power Solutions. “It aligns with our broader mission to engineer advanced, environmentally responsible propulsion systems for the ships of tomorrow.”
MOL, Kanadevia, and Yanmar Power Solutions reaffirm their commitment to continue leading decarbonization initiatives, enhancing the environmental performance of LNG as a marine fuel, and pioneering solutions that contribute meaningfully to global climate goals.
What is Methane Slip?
Methane slip refers to the unburned methane that escapes into the atmosphere during combustion in dual-fuel engines, particularly those running on LNG. Despite LNG’s significantly lower CO₂ emissions compared to conventional marine fuels, methane slip has emerged as a critical environmental issue due to methane’s high global warming potential.
What is EGR (Exhaust Gas Recirculation)?
EGR is a technology used to recirculate a portion of an engine’s exhaust gases back into the combustion chamber. In the context of LNG engines, it reduces both NOx emissions and methane slip by lowering combustion temperatures and enhancing the oxidation of unburned gases.
Kanadevia Corporation
Kanadevia Corporation (formerly Hitachi Zosen Corporation) is a major Japanese industrial and engineering company. Since its founding in 1881, Kanadevia has focused on providing solutions across several key segments, including Environmental Business (e.g., waste-to-energy plants), Machinery and Infrastructure, and the rapidly growing Decarbonization Business. In the marine sector, Kanadevia specializes in the manufacture of marine engines and denitrification catalysts, positioning it as a key technological provider for advancing clean energy and reducing the environmental impact of large-scale industrial operations.
Yanmar Power Solutions Co., Ltd.
Yanmar Power Solutions is a specialist company within the Yanmar Holdings Group, focusing on large marine propulsion and auxiliary engines as well as land-use power generation applications. Established in 2025 to enable more agile operations, the company leverages Yanmar’s century of expertise in diesel engine technology to advance multi-fuel and decarbonization technologies, including solutions for hydrogen and methanol. Yanmar Power Solutions is a driving force in providing high-efficiency, sustainable engine systems for the global marine and power generation industries.
About Mitsui O.S.K. Lines, Ltd. (MOL)
MOL is a global leader in shipping, operating over 800 ships worldwide. Its diverse fleet includes bulk carriers, liquefied natural gas carriers, Ro-Ro car carrier ships, and oil tankers, among others. Beyond traditional shipping, MOL also engages in social infrastructure businesses, including real estate, terminal and logistics, and offshore wind power. With one of the largest merchant fleets and 140 years of history, MOL aims to be a resilient corporate group that provides new value to all stakeholders.
Source Mitsui O.S.K. Lines