Decarbonisation Technology – August 2021

FACTS

emissions can be problematic as the marine engine market consists of different engine technologies for different applications. This results in different engine characteristics, and hence a range of different GHG intensities. However, it is possible to make an indicative statement that the use of LNG as a marine fuel has a GHG benefit over the use of marine fuel oils in the range of 4-23%, depending on the engine technology. Taking into account the current global shipping fleet broken down by engine technology and corresponding fuel, the total GHG emissions could be reduced by 15% simply by switching from oil-based marine fuels to LNG. Technical developments and improvements in the LNG supply and LNG engines have the potential to significantly increase the benefits from the use of LNG as a marine fuel. Independent of the engine technology, the study shows that LNG provides a major advantage in improving air quality, which is particularly relevant in ports and coastal areas. Beyond the benefits associated with reducing air pollutants, LNG can play an important role in reducing GHG emissions of international shipping by at least 50% by 2050 (compared with 2008) and contribute to the IMO GHG reduction target. Finally, considering the entire life cycle from well-to-wake, including primary feedstock production, fuel processing, transport, bunkering and operational use, is essential for comparing conventional fuels with alternative ones. It avoids a shift of burdens between single supply chain steps, such as a shift of GHG emissions caused during engine operation, to the production of the fuel. It is also fundamental to establishing a level playing field for fuel comparisons with the ambition to develop a low- and zero-carbon shipping industry. A simple analysis of the tank-to-wake GHG emissions, as currently mandated by IMO, seems to be lacking the whole picture.

LNG is mostly methane, a potent GHG that can trap 30 times more heat than the same amount of CO 2 in the atmosphere over 100 years. LCA is a methodology for evaluating the potential environmental impacts throughout its entire life cycle, from raw material extraction to end of life. It quantifies the material, energy inputs and outputs of all unit processes that comprise the product system under study. It helps us better understand the full climate impacts of using LNG as a marine fuel.

14% reduction compared with the same engine running on VLSFO.

For these LNG-fuelled engines, the WtW GHG emissions of the supply chain contribute about 20-22% of the entire life cycle emissions (WtW). For oil-based fuels, the supply chain accounts for 15-16%. Conclusions The study is based on high-quality, reliable and up-to-date industry-provided life cycle data for oil-based fuels and the use of LNG as a marine fuel. It has been conducted per ISO 14040:2006 and ISO 14044:2006 standards for data quality and the completeness and consistency of the model. The Project Consortium has validated the study data. The study has been critically reviewed in accordance with ISO/TS 14071:2018 by an independent expert review panel. The study demonstrates the benefit from reduced GHG emissions from the use of LNG as a marine fuel compared with fuel oils. The lower carbon content and higher energy content of LNG compared with the other marine fuel oils led to a better overall GHG performance, which more than offsets the higher GHG profile in the LNG fuel supply chain. The study also shows that generic reports of the benefit of LNG concerning GHG

Bambi Majumdar Sphera Oliver Schuller Sphera