April 15, 2019
Independent Study: LNG Reduces Shipping GHG Emissions by up to 21%

A new Well-to-Wake study has confirmed LNG can be a major contributor in meeting IMO’s 2050 Greenhouse Gas (GHG) targets for shipping.

The independent study report has revealed that 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). It also confirms that emissions of other local pollutants, such as sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM), are close to zero when using LNG compared with current conventional oil-based marine fuels.

GHG Emissions from Current Marine Engines

The study, commissioned by SEA\LNG and the Society for Gas as a Marine Fuel (SGMF), was conducted by leading data and consultancy provider thinkstep according to ISO standards. The report, which has been reviewed by a panel of independent academic experts, is the definitive study into GHG emissions from current marine engines. 

Emission Reduction for 2- and 4-stroke Engines

On an engine technology basis, the absolute WtW emissions reduction benefits for LNG-fuelled engines compared with HFO fuelled 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.

Readily Available and Operational Protocols in Place

Study partner Chad Verret, SGMF Board Chairman, added: 'LNG is safe to use, fully compliant and readily available as a marine transport fuel. Standards, Guidelines and Operational Protocols are all in place to ensure that the safe way is the only way when using gas as a marine fuel. LNG meets and exceeds all current and 2020 marine fuel compliance requirements for content and emissions, local and GHG. With the world LNG bunker vessel fleet doubling in the next 18 months and those vessels being deployed at major bunkering hubs, LNG as a ship fuel is rapidly becoming readily available.'

Towards Bio- and Synthetic LNG

Ongoing optimisation in supply chain and engine technology developments will 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.  

Primary Data, ISO Standards and Objective Academics

Dr Oliver Schuller, Team Lead Energy & Mobility at thinkstep stated: 'The main goal of this study was to provide an accurate report of the life-cycle GHG emissions from LNG as a marine fuel compared with conventional marine fuels.'

'This is a comprehensive report using 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. It is quality assured in assessing the supply and use of LNG as a marine fuel according to ISO standards. And objective, having been peer-reviewed by leading academics from key institutions in France, Germany, Japan and the USA.'

The full Well-to-Wake GHG Emissions Lifecycle Study can be accessed on the Thinkstep website.

Picture by SEA\LNG.