The 2nd Life Cycle GHG Emission Study on the use of Liquified Natural Gas (LNG) as a marine fuel has shown that greenhouse gas (GHG) reductions of up to 23 per cent are achievable now from LNG, compared with current oil-based marine fuels over the entire life cycle from Well-to-Wake.
The study, commissioned by industry organisations SEA-LNG and the Society for Gas as a Marine Fuel (SGMF), was conducted by Sphera and peer-reviewed by a panel of independent academic experts as an update of the first GHG study published by thinkstep in 2019.
The new study found that, in addition to the considerable air quality benefits it delivers, LNG could “beyond question” contribute significantly to the International Maritime Organisation’s (IMO) GHG reduction targets, setting out a 50 per cent cut in GHG emissions from international shipping by 2050 compared with 2008.
“Sphera conducted a milestone study on the GHG emissions associated with the use of LNG as a marine fuel in the Maritime Transport Sector,” commented Steve Esau, General Manager at SEA-LNG.
The study includes the latest data for the fuel supply consumption mixes, as well as the latest fuel consumption and emission data for the different ship engines. All data are based on information from key energy suppliers and all major marine engine manufacturers including Caterpillar MaK, Caterpillar Solar Turbines, GE, MAN Energy Solutions, Rolls Royce (MTU), Wärtsilä and Winterthur Gas & Diesel, as well as from ExxonMobil, Shell and Total on the supply side.
The study reveals that on an engine technology basis, the Well-to-Wake GHG emissions reduction benefits are between 14 to 23 per cent for 2-stroke slow-speed engines and between 6 to 14 per cent for 4-stroke medium-speed engines compared with oil-fueled engines.
The study forecasts that, by 2030, 2-stroke engines using LNG will offer GHG benefits of up to 24 per cent, 4-stroke engines of up to 22 per cent and technological improvements will significantly reduce and minimise methane emissions.
Methane emissions from the supply chains as well as methane released during the onboard combustion process (methane slip) have been included in the analysis.
The study is the first on a series of regular updates of greenhouse gas emissions to reflect ongoing technology developments in fuel supply and marine propulsion systems.