Converting commercial ships on the high seas to CO2-neutral drive systems is a huge challenge. One important factor is the range requirement of the individual ship types. This must be as large as possible for cruise ships, tankers and container ships in order to be able to cover the long routes across the world’s oceans without stopping. Route flexibility and ranges of more than 5,000 nautical miles are basic requirements of the world’s maritime fleet.
Purely battery-electric solutions are often out of the question for these deep-sea applications due to their high weight and space requirements. Hydrogen as a direct energy storage medium is also ruled out for these ship types, as its low volumetric energy density would require it to be stored in huge hydrogen tanks in a cryogenic or highly compressed state. This is not a sustainable option for the maritime industry, Freudenberg says.
Nevertheless, fuel cells have tremendous advantages due to their high efficiency and low maintenance requirements. Therefore, it makes sense to bind regeneratively produced hydrogen chemically to achieve a significantly higher energy density. This will make fuel cells economically and practically viable for ocean-going shipping. The fuel cell system can be flexibly combined with a maritime battery systems to create particularly efficient hybrid solutions.
In this context, the use of climate-neutral methanol represents a turning point on the road to maritime sustainability and the achievement of IMO emission reduction targets, Freudenberg posits.
Freudenberg e-Power Systems has developed an approach to using methanol for marine applications that combines highly efficient fuel reforming technology with a long-life PEM fuel cell in a modular, scalable system unit.
It generates hydrogen via steam reforming, which then reacts with oxygen from the air in the fuel cell to produce the electrical energy needed for both propulsion and the ship’s electrical system. The heat required for the reformer can be obtained directly from the waste heat of the fuel cells. Fuel cell stack, reformer and control electronics as well as all components for media supply are located in a prefabricated, modular unit. This containment design facilitates easy installation on board.
The safety concept of this system architecture has now received Type Approval from the classification society RINA. This confirms the safety of the system and its conformity with maritime standards and regulations.
Already optimized for heavy loads at the cell level, the special material configuration of the bipolar plates (BPP) and the membrane electrode unit ensure the necessary high efficiency and durability required for heavy-duty applications.
Freudenberg’s safety concept was already tested for maritime conformity in an early phase of the “Pa-X-ell 2” research project. For this purpose, it received “Approval in Principle” from the classification society DNV GL. In addition to the focus on the safety concept, the topics of modularization and standardization were considered in order to take account of the aspects of large-scale industrialization from the very beginning.
In the future, system units with a respective nominal output of 500 kW are to be combined into total capacities in the double-digit megawatt range. In addition to Freudenberg, the project consortium focusing on passenger shipping includes the partners Carnival Maritime (AIDA Cruises), Meyer Werft as well as Lürssen Werft, besecke, DLR, EPEA and the classification society DNV GL.
The “HyFleet” research project launched in 2021 shows that the consistent design strategy with lifetime and efficiency as priorities is also well suited for other segments. Together with its project partners ZF Friedrichshafen and FlixBus, Freudenberg is working to replace conventional diesel drives in long-distance buses. Initial test results show that a service life of at least 35,000 hours can be achieved. This corresponds to a total service life of 1.2 million km for a truck.
Freudenberg e-Power Systems is part of the global Freudenberg Group, which has four business areas: Seals and Vibration Control Technology, Nonwovens and Filtration, Household Products as well as Specialties and Others. In 2021 the Group generated sales of more than €10 billion and employed more than 50,000 associates in around 60 countries.