Steve Esau, Chief Operating Officer, SEA-LNG:

 The maritime energy transition is a complex topic so while we welcome analysis which generates meaningful insights this study is predicated on questionable assumptions.  First, it states that e-ammonia is the only viable and scalable solution for maritime decarbonisation.  Second, it discounts the decarbonisation pathways offered by methane and methanol, characterising them as “dead-ends”.

All synthetic, or e-fuels, face a common scaling challenge, namely access to large volumes of renewable, or green hydrogen feedstock, at low cost. Green hydrogen accounts for 70%-80% of the cost of all e-fuels.  A claim that a world exists in which e-ammonia is scalable while e-methane and e-methanol are not, despite drawing on the same feedstocks is difficult to justify.

The methane molecule offers a robust, incremental and scalable pathway for maritime, starting with LNG today via liquefied biomethane (LBM / bioLNG) in the short to medium term, with e-methane the long-term destination. This is a practical and realistic route that leads to net-zero maritime GHG emissions and ensures investments in LNG dual fuel assets are futureproof. The methane pathway is happening now, with volumes of LBM bunkers scaling rapidly in Europe.

LBM and e-methane can be dropped into established LNG infrastructure and used in the existing LNG dual fleet with no modification required. This means investments can be focused on scaling up the production of these green fuels rather than establishing or modifying infrastructure, equipment or vessels.

LBM and e-methane can be blended with LNG in any ratio. This fuel optionality allows shipowners and operators to reduce the emissions intensity of their fuels incrementally in line with supply, their voluntary decarbonisation ambitions, and compliance targets. E-methane project development continues in Europe, North America, South America, Australia and Asia driven by demand from utilities. Some 150kt pa of capacity is in FEED and a further 1 Mtpa at a pre-feasibility feasibility stage. Initial e-methane bunkering is expected to emerge in the next few years

LNG provides an up to 23% reduction in GHG emissions on a well-to-wake basis, including methane slip and upstream leakage, with exact reductions depending on the engine technology and supply chain used. [Source: Sphera’s 2nd Life Cycle GHG Emission Study on the Use of LNG as Marine Fuel].  Consequently, as the methane pathway starts with the immediate GHG reductions in its fossil (LNG) form, unlike other alternative fuel pathways such as ammonia and methanol whose fossil starting point is one of far higher emissions than traditional marine fuels, it offers the lowest cost solution for regulatory compliance.

Advantages continue on the revenue side.  Methane fuels have 1.6 times the volumetric energy density of methanol and twice the energy density of ammonia. A fuel with a lower energy density (calorific value) means either larger fuel tanks are required, leaving less space for revenue-generating cargo, or more frequent bunkering operations are needed. At the end of the day, ship operators want to minimise their fuel spend and carry cargo, not bunker fuel. Again, methane is optimal.

Seafarer welfare and safety are key concerns for the adoption of new marine fuels along with challenges of ensuring safe bunker operations in ports. LNG has been safely shipped around the world for 60 years with no major accidents, rigorous safety standards are in place, and crews have had thorough training on how to handle, store and bunker, as well as operate LNG dual fuel engines. Ammonia faces significant challenges in terms of its toxicity for humans and marine life, which need to be addressed before it can safely be adopted as a mainstream marine fuel.

At SEA-LNG we believe that maritime will always have a “basket of fuels” to support global operations, this study is predicated on the wrong assumption that green ammonia is the only scalable solution for maritime.  Given the challenges facing this and other potential alternative fuels, the methane runway is currently the most practical and realistic fuel choice for new builds for the maritime industry, a choice that is increasingly reflected in the order book.