Designing a future-proof solution – being prepared for the carbon-free marine fuel

Antti Yrjänäinen


Antti Yrjänäinen
M. Sc. (Naval Arch.)

One of the biggest races to cut greenhouse gas emissions is happening at sea. In light of the latest carbon dioxide emission regulations set by the International Maritime Organization (IMO), shipowners are actively seeking innovative ship concepts to transition to more eco-friendly fuels. Leading the way to zero emissions, Nippon Yusen Kabushiki Kaisha (NYK Line) and Elomatic have developed a concept that offers scalability for future deployments. When the post-LNG phase is properly considered in advance, conversion costs remain modest.

Japan’s NYK is a forerunner in the market when it comes to transforming their fleets to greener technologies. Nearly 15 years ago, NYK selected Elomatic to conduct a technology study for a large container vessel presented as a futuristic ship concept. This fruitful collaboration continued with another project aimed at designing a future-proof pure car carrier (PCC) for 2050.

Building on this success, NYK once again partnered with Elomatic approximately two years ago to develop a very specific future vessel concept – the Ammonia-Ready LNG-Fueled Vessel. NYK’s objective is to prepare for the post-fossil fuel era by exploring future fuel solutions now.

In search for a next-bridge solution

NYK tasked Elomatic to design two ship concepts closely resembling their current state-of-the-art vessels but operating on an alternative fuel source. This concept aimed at identifying the most viable green fuel as the industry makes concerted efforts to move away from hydrocarbon-based fuels.

The concept serves as a next-bridge solution to enable NYK to convert their existing LNG-powered vessels to ammonia at a minimum cost once green ammonia becomes commercially viable and ship engines are suitably engineered to utilize it. By considering the vessel’s next phase in advance with tank and other component arrangements, the conversion to ammonia can then be easily done when the time is right.

LNG is serving as an effective interim solution, enabling shipping companies like NYK to significantly reduce their greenhouse gas emissions – but is not enough to meet future environmental requirements. With the concept, NYK can seamlessly convert their hydrocarbon-based vessels to run on green fuel, achieving complete decarbonization and compliance with upcoming legislation.

Green ammonia – best for deep-sea shipping

Elomatic studied the different future fuel alternatives. Among green fuels derived from hydrogen, carbon-free green ammonia has been projected to have the lowest production expenses – even with the technology we have today. For local transportation, vessels can use direct electricity with battery packs.

Methanol is another green option, and engines are already available. Hydrogen containers, either liquid or pressurized, have very limited opportunities in shipping due to the vast hydrogen volume requirement. Ammonia takes advantage of hydrogen’s energy in a more convenient form. Therefore, ammonia is the optimal choice for deep-sea shipping.

Focus on climate change

Ammonia’s energy density is much less than that of hydrocarbon-based marine fuels, such as heavy fuel oil (HFO) or marine gas oil (MGO). Earlier, HFO was the source of choice. Then starting from the Paris Agreement adopted in 2015 by nearly every nation to fight climate change, maritime emission regulations came into force.

Environmental pollution was the driver to cut back initially on sulfur oxides, and later toxicity was the driver to minimize NOx emissions. More recently, lowering CO2 emissions has been the focus due to accelerating climate change.

A versatile concept for several vessel types

Elomatic began working with NYK and the Monohakobi Technology Institute (MTI), a member of the NYK Group, on two concurrent projects involving different vessel types. The teams worked in parallel to deliver two concepts first, followed by two more.

The Finnish design group at Elomatic participated in regularly scheduled meetings with the MTI group, which was responsible for the larger technology scope. Elomatic’s team members were involved in five different working groups with their Japanese counterparts.

To date, Elomatic has designed concepts for an ammonia-ready car carrier, a post-Panamax bulk carrier, a capesize bulk carrier and a very large crude carrier (VLCC). In the next project phase, Elomatic aims to work with shipyards and marine equipment manufacturers on the actual design based on the concept work. 

Studies show that if the post-LNG phase is properly considered in advance, conversion costs stay at a moderate level, making the concept a cost-efficient way to transition to the use of ammonia, regardless of the type of vessel.

Designing for as-yet-unknown technology

Elomatic used NYK’s existing state-of-the-art vessels of a similar size and type as a reference for future-proof ammonia-fueled vessels. But since the technology is not yet available, the teams needed to prepare for solutions that would be coming, perhaps even many years ahead. One issue was how to store the fuel; another was that there are no ammonia engines on the market yet.

Extensive discussions were held with engine manufacturers to get a better understanding of the potential changes needed or retrofitting requirements. Other key considerations included the fuel supply system, bunkering procedures and managing ammonia’s high toxicity.

Safety and reliability were paramount in every design decision. This encompassed engine modifications, safety systems, tank size and positioning, enclosed compartments, protective structures, the philosophy for containing toxic zones as well as compliance with emerging regulations. It was possible to implement certain rules and regulations with specific protocols regarding toxicity, although the actual rules are currently being defined by IMO and classification societies.

Tackling differences in current fuel usage

Ammonia and LNG have many similar technology considerations when it comes to rules and regulations. All fuel pipes are double-walled, and all spaces exposed to the gases must have proper ventilation. Ammonia is also very corrosive, which makes it essential to select the right materials for the tanks and fuel supply systems. Since ammonia has a lower energy density than conventional fuel, the ships also were designed with larger fuel tanks.

The concept solves the challenges of ammonia use, such as the fuel tank material and placement along with the hub durability and stability. All safety rules being developed for future-proof ships powered with ammonia have also been considered.

Innovative process to match outcome

Elomatic used its facilitated innovation process as part of ship concept development to gather ideas, explore opportunities and address design challenges for the concept. The entire project needed a new approach to developing future ship concepts that align with evolving industry needs. Repeating old ship designs no longer works.

In the first project with two distinct vessels, Elomatic proposed two unique solutions. For one vessel, the interior compartment was expanded, allowing for an increased deck area. The other vessel, a bulk carrier originally designed as an LNG vessel, was reconfigured to accommodate ammonia usage by cutting the vessel to create space for an additional tank compartment. These customized solutions allow the existing vessels to meet the upcoming regulation changes.

The future-proof ship concepts cover various operational specifications, including load capacity, voyage distance, ship speed and fuel capacity.

When to switch to ammonia?

The time to switch to green fuels will come gradually. First, vessel engines that can operate on these fuels are needed. Those will be coming only in a couple of years. The big engine manufacturers are currently testing and fine-tuning their engine concepts for the market.

The new fuels need to be commercially available in every port where carbon-free ships operate. These fuels also need to be priced competitively in the market. Legislation, too, is needed for this transformation to proceed. A European emission trading system (ETS) is coming that will benefit carbon-free vessels in European waters. Or companies may request to use only green supply chains in the future, creating a demand-based driver by end customers.

The decision to switch to future-proof ship concepts will ultimately depend on operational costs. It is also essential to consider the vessels’ operational profiles and optimize the tradeoff between range and energy density of low-density fuels, since these vessels have reduced payload due to larger tanks and limited space.

First-movers are ready for the future

One of the most satisfying parts of the project was the cooperation. The teams created new solutions together and were very involved in exchanging knowledge. Elomatic also provided visualization services and extensive technical support as part of the project scope.

Moreover, Elomatic brought a wealth of knowledge and experience of ammonia from land-based projects to the collaboration. Additionally, they could share experience from other new fuels, like methanol, for which engines are already available, and from retrofitting other LNG vessels. Still, the company predicts that ammonia will be more cost efficient in the long run. 

Elomatic has a long history with NYK, and the projects have always been very forward-looking. For a company focusing on engineering solutions, projects involving game-changing technology are always the most fascinating. As a major shipowner, NYK has hundreds of vessels. They are open to testing different solutions to prepare for carbon-free future fuels.

Check out our videos on the subject

Ammonia-Ready LNG-Fueled Vessel – Bulk Carrier

Ammonia-Ready LNG-Fueled Vessel – VLCC