LARGE BORE FOCUS IN METHANE SLIP REDUCTION PROJECT

New advanced combustion technology designed to reduce methane slip is being developed for Wärtsilä’s large bore engine platform after earlier success with smaller engines

The EU-funded Green Ray project is developing onengine technologies for low-pressure dual-fuel engines – both 2- and 4-stroke – as well as a novel aftertreatment concept. These solutions will be advanced to a high state of technology readiness, including demonstrators installed on two newbuildings and one retrofitted to an existing vessel.

As part of the project, Wärtsilä is developing technology specifically for low pressure 4-stroke dual fuel engines that enables methane slip reduction, increased efficiency and lower operational costs at all engine loads. The project is in line with Wärtsilä’s aim is to demonstrate slip rates of one gram per kWh, a significant reduction compared to existing performance.

“This research will allow us to build on the continuous improvements made in reducing methane slip from gas engines over the past 20 years,” said Sebastiaan Bleuanus, General Manager, Research Coordination & Funding, Wärtsilä Marine Power. “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 technology development for the project targets the largest four-stroke engines on the market as widely used by cruise ships, ferries and gas carriers. It follows and expands on the developments achieved as part of the EU-funded SeaTech project which began in 2019 and included also the development of sophisticated control and combustion systems for Wärtsilä dual-fuel 31 engines. The resulting optimisation could only be achieved by using the advanced engine concepts Wärtsilä already employs.

Another facet of the work undertaken by the Green Ray project will be to measure methane slip on existing modern engines, to update public domain data that can be as much as a decade behind current technology. “This is a key collaboration we are seeing in the Green Ray project,” says Bleuanus. “Industry and academia are pulling together not only to solve the problem of methane slip, but to also make insightful progress on current emission levels.”

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.

Additionally, 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 not only in significantly reducing methane slip (over 90%), but also in handling typical compounds that can degrade the catalyst, via the inclusion of a guard bed. It can be used as a stand-alone solution or combined with either the 2- or 4-stroke engine developments to further reduce methane slip.

The new technologies will be demonstrated at sea in real application during the project in collaboration with the Green Ray partners. Coordinated by VTT Technical Research Centre of Finland, these project partners include Chantiers de l’Atlantique, CMA CGM, DNV GL, Shell, the Finnish Meteorological Institute, MSC Cruises Management and non- profit organisation Revolve Water. The project will run until 2027, with commercialization of the technologies expected soon after.

The four-stroke combustion developments will be trialled on one of the Wärtsilä large bore engines to be installed on a dual-fuel cruise ship newbuilding currently being built at Chantiers de l’Atlantique for MSC. For Bleuanus, the approach involving collaboration between such partners accelerates the development process. “In collaborative projects where we have customers involved, we can actually achieve the technology demonstration quicker than what was possible, say, a decade ago. We really see that through these collaborative projects the pace of development is increasing.” He cites other projects that Wärtsilä has partnered in as further examples of this collaborative approach, including the Chek coordinated by the University of Vaasa and Wärtsilä’s Partner Campus.

He believes that the inclusion of shipping in the EU ETS is a positive move for the industry, as it will enable the revenue obtained to be fed back into more collaborative projects aimed at large-scale decarbonisation. “It’s not about one or two demo ships. It’s about 60,000 ships involved in international shipping, so we really need to get the scale up happening.”

The Green Ray project has received funding of around €7 million from Horizon Europe. It will run until 2027.