The shipping industry is a significant contributor to greenhouse gas (GHG) emissions, primarily due to the combustion of fossil fuels in marine engines. The maritime fuel cell module is indeed pioneering in the maritime industry. It represents a cutting-edge technology that has the potential to revolutionize how ships and other marine vessels are powered. The maritime fuel cell module is designed to be adaptable and easily integrated into various types of vessels, including cargo ships, passenger ferries, yachts, and naval vessels. The introduction of maritime fuel cell modules requires collaboration among stakeholders, including shipbuilders, maritime companies, fuel cell manufacturers, and regulatory bodies. These collaborative efforts promote knowledge sharing, technology exchange, and the establishment of standards and guidelines, facilitating the widespread adoption of this pioneering technology in the maritime industry.

Fuel Cells Technologies for Ships

Fuel cells operate by converting chemical energy from fuels such as hydrogen or methanol into electricity through a chemical reaction, without combustion or emissions of harmful pollutants. The type of electrolyte used by fuel cells determines how they are categorised primarily. The type of electro-chemical reactions that occur in the cell, the type of catalysts needed, the temperature ranges in which the cell functions, the fuel needed, and other characteristics are all determined by this classification.

Fuel cells are currently being developed in a variety of forms, each with unique benefits, restrictions, and possible applications.

Proton exchange membrane fuel cells (PEMC), also known as polymer electrolyte membrane fuel cells, have the advantages of low weight and volume when compared to conventional fuel cells and produce high power densities. PEM fuel cells use porous carbon electrodes with platinum or platinum alloy catalysts and a solid polymer as an electrolyte. To function, they just require water, oxygen from the air, and hydrogen. Usually, storage tanks or reformers supply them with pure hydrogen for fuel. Around 80°C (176°F) is the operating temperature of PEM fuel cells. They can start faster (with less warm-up time) and have less system component wear and tear when operating at low temperatures, which increases their durability.

Direct methanol fuel cells (DMFCs) are powered by pure methanol, which is usually mixed with water and fed directly to the fuel cell anode. Direct methanol fuel cells do not have many of the fuel storage problems typical of some fuel cell systems because methanol has a higher energy density than hydrogen though less than gasoline or diesel fuel.

Alkaline fuel cells (AFCs) have an aqueous solution of sodium hydroxide or potassium hydroxide as the electrolyte. These fuel cells are closely related to conventional PEM fuel cells, except that they use an alkaline membrane instead of an acid membrane. The rapidity of electro-chemical reactions in AFCs that gives them their great performance. Depending on the fuel and oxidizer used as well as the methodology used to calculate them, overall efficiency can range from 30 to 80 percent.

Phosphoric acid fuel cells (PAFCs) use porous carbon electrodes with platinum catalysts and liquid phosphoric acid as the electrolyte. The acid is contained in a Teflon-bonded silicon carbide matrix. When compared to other fuel cells of the same weight and volume, PAFCs are also less powerful. These fuel cells are often big and hefty as a result. The cost of PAFCs is likewise high. They are more expensive than other types of fuel cells because they need significantly higher loadings of pricy platinum catalyst.

MCFCs (molten carbonate fuel cells) The electrolyte used in MCFCs, high-temperature fuel cells, is a molten salt and carbonate solution floating in a porous, chemically inert ceramic lithium aluminium oxide matrix. When connected to a turbine, molten carbonate fuel cells can achieve efficiencies of up to 65%, which is far greater than the 37%–42% efficiencies of a phosphoric acid fuel cell operation. Overall fuel efficiency can reach over 85% when waste heat is recovered and utilised

The electrolyte in solid oxide fuel cells (SOFCs) is a dense, impermeable ceramic composition. The efficiency of SOFCs in turning fuel into electricity is about 60%. Cogeneration applications, which are meant to capture and use the system’s waste heat, might achieve overall fuel consumption efficiencies of over 85%.

Comparative study on type of Fuel cells:

PEMFC is commercially available and has the potential for zero emissions, but is limited by expensive materials and hydrogen storage and transport issues. SOFC, on the other hand, are fuel-flexible and can use ammonia, hydrogen, LNG, and other fuels, making it potentially more cost-effective at high volumes. Additionally, SOFC has a high temperature operation of 800C and can achieve efficiencies of >80%, resulting in less ammonia or hydrogen consumption per mile.

However, SOFC technology and green ammonia as fuel are not readily available and currently limited by few suppliers and high costs. The most promising fuel cell options for maritime applications are PEMFC, MCFC, and SOFC. Optimized system design and operating strategies, including hybrid systems coupling fuel cells with batteries, solar PV, or diesel generators, and co- and tri-generation systems coupling fuel cells with GT and HVAC, are important considerations.

Technical feasibility has been verified, but more real-world data is needed for convincing results. Large-scale applications in transport sectors in the future are expected to reduce costs to an acceptable level, and regulatory requirements, infrastructure investment, and development of design rules and operational guidelines should accompany technology development.

Guidelines and Risk Assessment

At its 105th session from 20 to 29 April 2022 IMO’s Maritime Safety Committee (MSC) approved the Interim guidelines for the safety of ships using fuel cell power installations, The International Maritime Organization (IMO) has developed guidelines for the safe use of fuel cells in the marine industry. These guidelines, known as the Guidelines for the Safe Operation of Ships Using Low-flashpoint Fuels (resolution MSC.391(95). The Interim Guidelines provide criteria for the arrangement and installation of fuel cell power installations with at least the same level of safety and reliability as new and comparable conventional oil-fuelled main and auxiliary machinery installations, regardless of the specific fuel cell type and fuel. An extensive range of risk assessments must be carried out to be granted the “fuel cell” additional service feature, including:

• HAZID study of fuel cell spaces
• HAZOP study of fuel cell power system
• FMECA analysis of fuel cell power installation (if used for essential services)

These evaluations intend to distinguish and alleviate dangers to Crew members, the climate and the underlying respectability of vessels. Fuel cell systems and ship configuration should restrict the risk of explosions, the spread of poisonous chemical substances and fire flare-ups, guaranteeing that the wellbeing of the ship is kept up with.

Benefits in fuel cells application:

• Fuel cells can convert up to 60% of the energy in the fuel into electricity, compared to around 25-40% efficiency for diesel engines. This increased efficiency translates to longer operating ranges for vessels and reduced fuel consumption, further contributing to environmental benefits.
• Fuel cells run quietly, with noise levels similar to those of electric motors. This feature reduces noise pollution in marine environments, which is beneficial to marine life and enhances the comfort of passengers and crew.
• Fuel cells can operate using a range of fuels, including hydrogen, methanol, and natural gas. This versatility makes them a promising option for different marine applications, from small leisure boats to large cargo ships.
• Fuel cells have a longer lifespan compared to internal combustion engines, thanks to their simpler design and lack of moving parts. This longevity translates into reduced maintenance and replacement costs for vessel owners.

Challenges in fuel cells application :

• It is important to Develop and scale-up technologies for fuels other than hydrogen in fuel cells.
• Fuel cells are expensive to develop, manufacture, and install.
• Fuel cells require specific storage and delivery infrastructure, such as hydrogen refuelling stations or methanol tanks, which may not be widely available or accessible in all regions.
• Fuel cells currently have lower power density compared to internal combustion engines, limiting their use in some high-power marine applications, such as propulsion for large commercial vessels. Research and development efforts need to focus on improving the performance and efficiency of fuel cell systems to enable wider adoption.
• Fuel cells are complex systems, requiring specialized knowledge and expertise for their operation, installation, and maintenance. This complexity may pose challenges for vessel owners and operators who are unfamiliar with fuel cell technology. Building up a knowledge bank from feedback gathered during on-board operations, which can only be achieved over time
• Fuel cells operate with flammable fuels such as hydrogen or methanol, which can pose safety risks if not handled properly.

Current Scenario of fuel cells application:

Inland and short-sea vessels are particularly suitable for the integration of hydrogen fuel cells on board. They require limited installed power within the range currently available for fuel cells. The technology for fuel cell integration on large ships such as cruise ships and container ships is rapidly being developed and adapted to their needs. For the time being, fuel cells are primarily intended to supply auxiliary systems on large ships with electricity and offer an emission-free

solution for ships that are in port or using auxiliary power. The next big leap in technology will require scaling to fully power ships’ main propulsion systems

Fuel Cells Pilot projects and Demonstrations:

• Ballard’s Marine Centre of Excellence’s FCwave™ marine fuel cell module in house-developed had received the world’s first DNV Type Approval certification.
• The HYDRA project: This project, funded by the European Union, aimed to develop a fuel cell power system for inland waterway vessels. The project demonstrated the feasibility and effectiveness of using fuel cells for propulsion and auxiliary power on board ships.
• The EMBARK project: This project, led by Sandia National Laboratories in the United States, aims to develop a fuel cell power system for an offshore supply vessel. The project aims to demonstrate the feasibility of using fuel cells to power offshore vessels, which are typically powered by diesel engines.
• The Zero-Emission Vessels (ZEVs) project: This project, led by the Norwegian research institute SINTEF, aims to develop fuel cell-powered vessels for use in the aquaculture industry. The project aims to reduce emissions from the industry, which is a significant contributor to global greenhouse gas emissions.
• The launch of the world’s first hydrogen fuel cell-powered cruise ship, the AIDAnova, in 2018. The ship is equipped with a 1 MW fuel cell system that provides electricity for the ship’s propulsion and hotel functions.
• The development of a fuel cell system for a container ship by researchers at the Fraunhofer Institute for Marine Technology and Maritime Systems in Germany. The system uses methanol as a fuel source and can generate up to 2 MW of power.
• The development of a hydrogen fuel cell system for a fishing vessel by researchers at the Technical University of Denmark. The system uses hydrogen stored in metal hydride tanks and can generate up to 30 kW of power.
• According to China Classification Society China’s first hydrogen fuel cell powered boat, Three Gorges Hydrogen Boat No. 1, was successfully launched in Guangdong in mid-March 2023.

Conclusion:
The International Maritime Organization has set a target to reduce greenhouse gas emissions from shipping by at least 50% by 2050, which is likely to drive the adoption of cleaner technologies like fuel cells. The use of fuel cells in boats and ships is a rapidly evolving field with immense potential to transform the maritime industry towards sustainability. Despite the challenges associated with the high cost of fuel cells, the need for specific fuel infrastructure, and the safety concerns related to handling and storing flammable fuels, there can be rapid growth in the adoption of fuel cells in the maritime industry in the coming years.

Government policies, incentives, and regulations are expected to play a crucial role in promoting the deployment of fuel cell technology in the marine sector. Fuel cell technology has the potential to revolutionize the maritime industry by reducing emissions, increasing efficiency, and promoting sustainability. The future of fuel cells in boats and ships looks promising, and continued investments, collaborations, and innovations are critical to driving the growth and adoption of this transformative technology in the years to come.

– Riya Yadav