A lifecycle study by consultancy thinkstep, commissioned by SEA\LNG and SGMF, has found that greenhouse gas (GHG) reductions of up to 21% are achievable now from LNG as a marine fuel, compared with current oil-based marine fuels, over the entire life-cycle from Well-to-Wake (WtW).

The study also confirms that emissions of other local pollutants, such as sulfur oxides (SO_x), nitrogen oxides (NO_x) and particulate matter (PM), are close to zero when using LNG compared with current conventional oil-based marine fuels.

The Life Cycle GHG Emission Study is a long-awaited piece of the “LNG as a marine fuel“ puzzle. It not only confirms what we already knew in terms of LNG’s immediate impact on air quality, human health and its cleanliness, but clearly highlights the genuine, substantiated GHG benefits of using today’s marine engines capable of burning natural gas. Moving from current Heavy Fuel Oil (HFO) to LNG does reduce GHG emissions. LNG does contribute to the International Maritime Organisation (IMO) GHG reduction targets. And it is clear that LNG is the most environmentally-friendly marine fuel that is readily available and safe, both today and in the foreseeable future.

—SEA\LNG Chairman Peter Keller

On an engine technology basis, the absolute WtW emissions reduction benefits for LNG-fueled engines compared with HFO fueled ships today are between 14% to 21% for 2-stroke slow speed engines and between 7% to 15% for 4-stroke medium speed engines. 72% of the marine fuel consumed today is by 2-stroke engines with a further 18% used by 4-stroke medium speed engines.

Source: thinkstep.

The assessment of the carbon intensity of LNG was carried out on a full life cycle basis. This includes the following life cycle phases: production & processing; pipeline transport; liquefaction; LNG carrier transportation (for imports); LNG terminal operations (for imports); bunkering (dispensing); and the final combustion in the engine.

The report analyzes several LNG pathways, including LNG from Algeria, Australia, Qatar, Indonesia, Malaysia, Nigeria, Norway, Trinidad & Tobago and the USA. In addition to the life cycle GHG emissions, criteria pollutants, such as SO_x, NO_x, and PM, were considered for the use phase of the fuels.

The study uses the latest primary data to assess all major types of marine engines and global sources of supply, including:

• 2-stroke slow speed (most common for high-powered ocean-going ships which consume 72% of marine fuel);

• 4-stroke medium speed (18% of fuel usage, primarily in ferries and cruise ships);

• 4-stroke high speed (5% of fuel usage); and

• Others (5%).

Ongoing optimization in supply chain and engine technology developments can further enhance the benefits of LNG as a marine fuel. Additionally, bioLNG and Synthetic LNG—both fully interchangeable with LNG derived from fossil feedstock—offer the potential for significant additional GHG emissions reductions. For example, a blend of 20% bioLNG as a drop-in fuel can reduce GHG emissions by a further 13% when compared to 100% fossil fuel LNG.

The report uses the latest primary data to assess all major types of marine engines and global sources of supply with quality data provided by Original Equipment 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 from the supply side.

SEA\LNG is a UK-registered not-for-profit collaborative industry foundation serving the needs of its member organizations committed to furthering the use of LNG as a maritime fuel. The Society for Gas as a Marine Fuel (SGMF) is a non-governmental organisation (NGO) established to promote safety and industry best practice in the use of gas as a marine fuel.

SEA\LNG’s members include: ABS, Carnival Corporation & plc, Clean Marine Energy, DNV GL, Eagle LNG Partners, ÉNESTAS, Exeno Yamamizu, Fearnleys AS, Gasum, GE, GTT, JAX LNG, Keppel Gas Technology, “K” LINE Group, Lloyd’s Register, MAN Energy Solutions, Maritime and Port Authority of Singapore (MPA), Marubeni Corporation, Mitsubishi Corporation, Mitsui & Co., Ltd., Naturgy, Novatek Gas & Power, NYK Line, Petronet LNG, Port of Rotterdam, Qatargas, Shell, Société Générale, Sumitomo Corporation, Total, TOTE Inc., Toyota Tsusho, Uyeno Group of Companies, Port of Vancouver, Wärtsilä, and Yokohama-Kawasaki International Port Corporation (YKIP).