Methane Slip, Black Carbon and Greenhouse Gas Emissions from an LNG-Fuelled Cruise Ship: Insights from FuelEU and IMO Engine Load Monitoring Methodologies

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:This paper offers high-quality empirical emission factors for LNG marine engines, valuable for lifecycle analysts and climate modelers.

🏢実務担当者:Shipping companies can use the methane slip coefficients and operational profile insights to optimize engine operation and comply with FuelEU Maritime requirements.

🏛政策担当者:Regulators should note that default methane slip factors may overestimate actual emissions, and that engine load monitoring is essential for accurate GHG accounting.

Liquefied natural gas (LNG) is increasingly used in maritime propulsion systems to reduce atmospheric emissions. However, methane slip from dual-fuel engines remains a critical limitation due to the high global warming potential of methane. This study presents a comprehensive experimental assessment of greenhouse gas (GHG) emissions from a new-generation low-pressure four-stroke dual-fuel (LPDF 4-S) engine installed on a cruise vessel and operating on both LNG and marine gas oil (MGO). Measurements were carried out during full-scale sea trials under real navigation conditions. Results show that methane slip remains strongly dependent on engine load, with low and stable values at medium-to-high loads (1.95 g·kWh−1 average over the 60–90% range) and a value of 5.6 g·kWh−1 at 26% engine load. Compared with the previous engine generation (46DF), the 46TS-DF engine exhibits an approximate 18% reduction in methane slip above 60% load. On a well-to-wake basis, this results in an overall carbon dioxide CO2-equivalent emission reduction of about 6%, of which 42% is attributable to methane slip reduction and the remainder to improved energy efficiency. In contrast, switching from MGO to LNG operation leads to a 21% decrease in CO2-equivalent emissions. Black carbon (BC) emissions were measured and as expected despite the limited number of available studies, they were found to be significantly lower in LNG mode, with reductions exceeding 90% compared with MGO operation. Finally, an Engine Load Monitoring (ELM) analysis based on one year of operational data highlights the strong influence of vessel operating profiles on methane slip. The application of both International Maritime Organization (IMO) and FuelEU Maritime methodologies yields consistent methane slip coefficients (1.34% and 1.36%, respectively), significantly lower than current default values, noting that these estimates do not include crankcase emissions. These results demonstrate the importance of integrating real operational conditions into emission assessment frameworks for LNG-fuelled vessels.

• crossref https://doi.org/10.3390/jmse14141315first seen 2026-07-20 05:57:16