Wärtsilä introduces new version of its LNG dual-fuel engine that reduces methane slip

While operating on LNG, the upgraded version of its four-stroke dual-fuel engine reduces methane slip by 41% on average compared to its older version, Wärtsilä claims.

PHOTO: Wärtsilä’s four-stroke LNG dual-fuel engine. Wärtsilä

Methane slip occurs when unburned methane from ship engines escapes into the atmosphere. Since it is unplanned and therefore largely unmeasured, it poses a significant threat to the environment due to methane’s high global warming potential as a greenhouse gas (GHG). Methane emissions have up to 36 times higher global warming potential than carbon dioxide over a century, according to a World Bank study.

The new engine version can cut methane emissions on a 50 percent load point by up to 56% and nitrogen oxide (NOx) by up to 86%, the Finnish engine maker adds. The 50 percent load point in a ship refers to the point at which the ship's cargo or weight distribution is evenly balanced.

The new version of the engine is installed onboard Finnish ferry operator Wasaline’s RoPax (roll-on/roll-off passenger) ferry, Aurora Botnia, and has helped the ferry cut methane emissions by 10%, Wärtsilä further claims.

Compared to the older engine version, this new version “will enable operators to go even further in reducing methane emissions, helping to futureproof their vessels in the longer term against potentially tightening global requirements.”

According to the International Council on Clean Transportation (ICCT), methane slip is highest in low-pressure LNG dual-fuel engines and highest in high-pressure dual-fuel engines.

The company believes that “improving dual fuel technology to enable methane emissions reduction will have a major impact on the long-term viability of LNG as a marine fuel.”

Despite the issue of methane emissions, LNG has been gaining popularity among shipowners as an alternative fuel. The global LNG-fuelled fleet is currently made up of 448 vessels, with another 86 expected to join this year, classification society DNV data shows.

By Tuhin Roy

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