Flexible fuel options and a focus on methanol and ammonia increase in the container ship sector
Fuel flexibility is a key theme when it comes to meeting future decarbonisation requirements; ammonia and methanol are gaining traction in the container sector and LNG is as strong as ever.
The need to be flexible with fuel can be seen in several products and moves in the industry. Germany-headquartered TGE Marine has developed storage solutions that enable vessels to transition between LNG, ammonia and potentially methanol. Its senior sales director Dieter Hilmes explains, “TGE Marine offers multi-fuel containment systems based on type-C tanks. These tanks are made of a fuel-resistant material that gives the shipping company maximum flexibility in terms of fuel choice. However, conversions to the engines and the fuel treatment system are necessary, which is associated with significant costs. It is therefore not possible to change the fuel without further modifications. It does give shipping companies the option of changing the fuel as part of a major conversion without having to replace the largest, heaviest and most expensive component, which is often not physically possible.”
TGE Marine has completed the first orders equipped with type-C stainless steel tanks. These tanks meet the fuel-ready class notations for methanol and ammonia and are also suitable for LNG. Mr Hilmes explains, “Many shipping companies use LNG as fuel in the first years of operation after delivery of the ships because it is readily available, inexpensive and enables a significant reduction in emissions. Later, when sufficient CO2-neutral fuel is available, the shipping company can then switch to ammonia fuel while retaining the tank, the bunker stations and some components from the fuel gas handling room.”
This multi-fuel solution is also possible for container ships. But Mr Hilmes warns, “However, due to the lower calorific value of ammonia and methanol, the tank volume must be larger from the outset or bunkered more frequently.”
Elsewhere, there has been an increasingly speedy uptake of methanol in the container ship sector. Wärtsilä Marine general manager of decarbonisation and co-creation for power supply, Figosta Zhou says, “Methanol is gaining traction in the liner segment due to its favourable storage and handling characteristics. Unlike LNG or ammonia, methanol remains in a liquid state at ambient temperatures, simplifying fuel containment and supply system design. Green methanol, produced from renewable sources such as biomass or electrolysis-based hydrogen, offers a scalable pathway to near-zero emissions, so that is a huge area of interest. Given its compatibility with modified compression-ignition engines and existing fuel transport infrastructure, we expect a strong uptake in the next decade.”
Moving to ammonia, he comments, “Ammonia, meanwhile, presents a compelling long-term solution as a zero-carbon fuel, but its implementation is more complex. The challenges lie in combustion characteristics, NOx emissions, and the toxicity of ammonia, which necessitate specialised safety measures in fuel handling and onboard storage. We see great potential here and Wärtsilä, alongside classification societies and industry stakeholders, is actively working on overcoming these technical hurdles to make ammonia a viable fuel option for deepsea shipping through the EU-funded initiative, the Ammonia 2-4 project.”
