“We are at the heart of implementing decarbonization in the marine sector,” he says. “The engine technology remains the same, but the fuels do not, so we are really in the thick of things – or rather the thin of things, because these new fuels lack the viscosity of previous fuels,” he jokes.
Adopting new fuels poses a series of challenges for engine makers and the ecosystem around them. New ships are expensive and thus expected to serve for decades. Yet, at the same time, their fuel systems will have to significantly evolve and transform during that period to meet IMO targets in 2030 and 2050, while avoiding significant downtime and re-engineering. Equally, the new fuels are currently in short supply, so immediate reliance upon them is not a sure path. This combination of factors is driving a requirement for dual-fuel engines that can take both traditional and new fuels. “Diesel currently has the lion’s share, but the industry wants to be ready for methanol and ammonia now,” says Marco.
Marco Coppo, CTO, OMT
A world away from diesel
The new fuels pose their own challenges. “The new fuels lack lubricity and operate as cleaning agents, removing protective oil films from steel-made engine parts, thus rendering them more prone to rust if they’re exposed to moisture and oxygen,” says Marco. “Additionally, new fuels have a much lower viscosity, which means that risks of cavitation damage increase. Leakages through gaps are also much higher, which reduces hydraulic efficiency, and the impact between moving parts is not softened by the squish effect. So, we must adapt the design accordingly to achieve the expected service lifetime.”
Human safety is the top consideration, with some new fuels being potentially explosive and poisonous: “Ammonia can be very dangerous if not handled properly: it is deadly in concentrations higher than 300 parts per million, if inhaled. So, on top of what is necessary to achieve good injection and engine performance, it is necessary to design gas-safe components and systems. Any potential leakage needs to be collected in a dedicated sealed environment provided with detection sensors. Additionally, it must be possible to securely flush the fuel system components, to remove the slightest trace of the chemical, especially before maintenance can be carried out.”
Space around the engine is another major constraint, says Marco: “The diesel system is still required as a backup, to provide the pilot injection needed to ignite the new fuel. On top of that, we have to find space for the injection equipment for the new fuel, in the same small area where the diesel injectors are located. In this respect, two stroke engines and medium-speed engines are two very different arenas. Two-stroke engines have a single exhaust valve in the center of the cylinder head, so it is possible to place the injectors all around its circumference. So, on top of the three that exist for diesel, another three can be added for injecting the alternative fuel. Medium-speed engines have four valves, which leave just one space for the injector in the cylinder head center. In this case, we have to package both diesel and alternative fuel injection stages inside a single injector body that cannot become much larger than the standard diesel injector. That can be very tight.”
Accelleron - OMT - New fuel injectors to cope with carbon-free fuels
Upending business as usual
These challenges may sound daunting, but Marco says, “There’s no better time to be an engineer in the marine engine field than now: plenty of challenges and opportunities to grow and understand more about the complex physics involved.” In traditional engines, many of the challenges were effectively ‘solved’, and new developments only offered fractional incremental benefits to shipowners. “Now we’re scratching our heads quite a lot, but also inventing a lot of new solutions, which is the fun part of it,” adds Marco.
“We’re working with new materials and new processes, bringing in additive manufacturing to create novel and very compact designs with curved channels. We’re experimenting with new stainless steels that can reach high hardness without the usual penalty of them becoming brittle. We’re looking at new shapes and concepts for the critical parts of the injector to achieve endurance levels comparable with those of injectors for conventional fuels.”
Marco says that while hydrogen-based synthetic fuels appear to be the most promising and accepted route to transition from their fossil-based forebears, “We need to keep our eyes open.” Other possibilities remain: “It could be the case that carbon capture becomes very efficient, so that synthetic hydrocarbons become cheaper to produce; in this case, only the fuel production plants would need to evolve, and no investment would be needed to adapt port and vessel fuel systems. Also, some companies are investigating nuclear reactors for commercial vessels, eliminating the need for fuel injectors. Clearly, there won’t be a ‘silver bullet’ for decarbonization for some time.”
So, flexibility is the key. “In the end, there will be a portfolio of solutions, at least in the medium term. We need to have the agility to move and adapt to unknown opportunities. For land-based applications, such as power plants, we should also look at fuel injection for hydrogen, for example. You lose energy by turning hydrogen into other chemicals, like ammonia or methanol. If there are no constraints around fuel storage, the raw gas provides the most efficient way to use it. And this could be a way for OMT to expand outside the marine sector.”
Fast and flexible
Joining the Accelleron family has enabled OMT to accelerate its progress. “Accelleron is encouraging us to move further and faster, to grasp every opportunity in this rapidly evolving market in order to establish our leadership in this space. The strong backing of Accelleron has enabled OMT to reinforce itself in all areas of the business, so that we have the strength to quickly grow our product portfolio and to serve the demands of this growing market” says Marco.
“The current moment presents an enormous opportunity. Engine manufacturers are working hard to enable all their portfolio to run with new fuels, so they need to engage specialist suppliers for the core engine systems in multiple projects. In the fuel injection space of medium-speed engines, the supplier is normally decided during the engine’s design process and not changed thereafter. So, there are high barriers to entry, but at the moment many opportunities are arising. If we demonstrate that we can deliver what the customer expects, then it’s quite a secure business for decades afterwards.”
“Accelleron has encouraged us to grow and obtain as high a market share as possible. This trust and expectation is very exciting and, at times, a little bit intimidating! Previously, we were sized for developing two new products per year, from a blank sheet. Now, we’re running eight projects in parallel and we want to go even faster.”
Marco concludes: “It’s exciting and rewarding to feel that we are making a difference for our company, but also for the planet’s decarbonization.”