A consortium including technology group Wärtsilä has secured European Union funding to develop solutions minimising methane slip from marine engines, advancing the environmental and climate benefits of LNG as a ship fuel.

The Green Ray project, coordinated by the VTT Technical Research Centre of Finland, brings together several companies from across the shipping value chain: shipyard Chantiers de l’Atlantique, ship owner CMA CGA, classification society DNV GL, the Finnish Meteorological Institute, ship manager MSC Cruises Management, non-profit organisation Revolve Water and energy major Shell.
The project will develop on-engine technologies for low-pressure dual-fuel engines – both 2- and 4-stroke – as well as an after-treatment concept. Also included will be demonstrators installed on two newbuilds and one retrofitted to an existing vessel. All the technologies developed in Green Ray will also be fully capable to utilise bio or synthetic methane instead of fossil LNG.
Wärtsilä will develop technology specifically for low-pressure 4-stroke dual-fuel engines that enables methane slip reduction, increases efficiency and lower operational costs at all engine loads. This technology targets the largest four-stroke engines on the market as widely used by cruise ships, ferries and gas carriers.
Wärtsilä will also develop an on-engine technology for 2-stroke engines around a patented LNG injection system to reduce methane slip from tankers, container ships, etc. Both technologies will be demonstrated at sea in real application during the project in collaboration with the Green Ray partners.
The use of LNG as a marine fuel is accelerating, with a clear transition to cleaner fuels and a well-developed supply infrastructure. The issue of methane slip – unutilised and thus unburned fuel escaping into the atmosphere from engines and across the production and supply chain – is seen as one of the main challenges to wider uptake.
Kati Lehtoranta, Principal Scientist at VTT, commented: “Methane slip has become an important factor in ship owners’ decisions about whether to use LNG fuel. With these promising technologies, we aim to reduce the slip contributing directly to the reduction of the total greenhouse gas emissions, opening this pathway to an even wider segment of the maritime market.”
Shell has developed a proprietary methane abatement catalyst system that has been lab tested and scaled up to a field demonstration, where it was proven to be effective in reducing methane slip (over 90%) and also handling typical compounds that can degrade the catalyst, via the inclusion of a guard bed.
Alexander Boekhorst, VP of Gas Processing and Conversion Technology at Shell, stated: “Shell’s climate ambition to become a net-zero emissions energy business by 2050 will require us to explore a range of avenues that have the potential to help us, our partners, and customers to decarbonise the existing LNG value chain. We are continuously working to improve the value proposition of LNG through dedicated technology research, and we are keen to develop potential solutions to minimise methane slip at such a relevant project as Green Ray.”
Sebastiaan Bleuanus, General Manager of Research Coordination & Funding at Wärtsilä Marine Power, added: “This research will allow us to build on the continuous improvements made in reducing methane slip from engines over the past twenty years. Taking these solutions for newbuilds and retrofits to near commercial readiness will be an important step for the long-term viability of LNG as a marine fuel.”
The project has received funding of around €7 million from Horizon Europe and will run until 2027.










