Did you know that the Apollo spacecraft used fuel cells back in the 1970s? Despite the huge potential of fuel cells, they have not become a mainstream technology since then. At Royal IHC, we are confident that this is about to change.

And why is that? Combined with renewable alternative fuels, fuel cells offer a very clean alternative needed for the transition to sustainable maritime energy. Fuel cells are easy to integrate into dredging vessels because they are modular systems, allowing for optimisation of the drive system for each specific application. Another important advantage is the increased efficiency of the fuel cell compared to an internal combustion engine.

Schematic of different fuel cell types
Schematic of different fuel cell types - van Biert & Visser, 2022

How does a fuel cell work?

A fuel cell transforms the fuel into electrical energy through an electrochemical process. There are many different types of fuel cell. However, they are all based on the same principle. 

Most promising types of fuel cell

There are three types of fuel cell that appear to be the most promising for working vessels. Let's take a closer look at how these fuel cells are working: 

  1. LT-PEMFC -  Low Temperature Proton Exchange Membrane Fuel Cell,
  2. HT-PEMFC - High Temperature Proton Exchange Membrane Fuel Cell, 
  3. SOFC - Solid Oxide Fuel Cell.

1. Fuel cell with high purity hydrogen: LT-PEMFC  

The Low Temperature Proton Exchange Membrane Fuel Cell (LT-PEMFC) has an efficiency of about 45 to 55%. With negligible emissions, this type of fuel cell is a very clean option. The Toyota Mirai car and the Alstom Coradia iLint train are well-known applications of this type of fuel cell.

However, this fuel cell is limited to the use of pure hydrogen as a fuel. This requires either the storage of pure hydrogen on board or combining another fuel with a large fuel-processing plant. 

Frequent bunkering

Hydrogen storage on-board a dredger is a challenge because of the relatively low energy density of hydrogen compared to diesel. Using hydrogen as a fuel combined with fuel cells is therefore particularly suitable for working vessels with the possibility of frequent bunkering (for example when operating in coastal areas).

Hydrogen hopper dredger - H2-Hopper

Suitable application: zero-emission maintenance of coastal areas

The LT-PEMFC has been selected for the first hydrogen-fuelled trailing suction hopper dredger design. This dredger has been developed using Royal IHC’s LEAF philosophy (based on two key principles: Low Energy and Adaptive Fuel). It is specifically designed for zero-emission coastal maintenance.

2. Fuel cell for methanol: HT-PEMFC

The High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFC) has an efficiency of 40-50% and can tolerate up to 5% carbon monoxide (CO) in the fuel stream (Das, Reis & Berry, 2009*). As the fuel cell can run on methanol reformate, it is a good option for methanol-fuelled vessels. The technology is currently relatively immature (compared to LT-PEMFC) and there are few applications.

*Das S.K., Reis A., & Berry K.J. (2009). Experimental evaluation of CO poisoning on the performance of a high temperature proton exchange membrane fuel cell. Journal of Power Sources, 193(2), 691-698.

3. Fuel cell suitable for most renewable marine fuels: SOFC

For vessels requiring greater autonomy, the Solid Oxide Fuel Cell (SOFC) has a higher potential. This is a high-temperature fuel cell operating at 600-1000°C. The SOFC efficiency is around 50 to 60%. With energy recovery technologies, this efficiency can be further increased to 70%. A much slower response of this type of fuel cell to load variations is the disadvantage of the high temperature. To ensure the operation of the SOFC, this slow response requires a larger energy storage system. 


Read the CEDA Dredging Days 2024 paper 
In this paper it is discussed which types of fuel cells are most suitable for the dredging application in combination with the expected fuels of the future. 

Evaluating the potential of fuel cells for the dredging industry (of Mestemaker & van Biert 2024)
 

Runs on a wider range of fuels

The SOFC is less sensitive to fuel impurities and can operate on a wider range of fuels than the LT-PEMFC. The high operating temperature allows reformation and/or cracking of the fuel within the cell. This makes the SOFC suitable for the most promising renewable marine fuels of the future, such as e-methane, e-methanol, e-ammonia and green hydrogen. 

E-methane or LNG powered vessels with SOFCs will have no methane slip (a problem with current dual fuel engines) and will have negligible emissions of NOX, SOX and PM. There is a high concentration of COin the exhaust gas from an SOFC. This makes CO2 capture (in the case of carbon-based fuels) efficient and economically viable.

SOFC feasibility study in HELENUS project

SOFC's are currently too expensive and too large. However, within 5 to 10 years, this type of fuel cell is expected to become a viable energy generation system for ships. It is for this reason, Royal IHC is leading the development of concepts for SOFC-powered dredging and offshore vessels as part of the HELENUS project. This project aims to gain knowledge and demonstrate the feasibility of SOFCs in the maritime sector and is part of a consortium funded by the EU’s Horizon Europe programme. The project is also investigating the fuel flexibility of SOFC's for operation with different types of carbon-neutral fuels. 

No single solution for cleaner vessels

Fuel cells will become part of the maritime landscape over the next decade. Initially, their use will be in niche applications where their advantages are most valuable and their disadvantages are less relevant. Fuel cells will become more widely used as the technology matures. Despite our belief in the use of fuel cells on dredging vessels, each case and situation is unique and requires a tailored solution. There is no such thing as a one-size-fits-all solution for cleaner dredging vessels. We can help you find the best solution with our expertise in the use of alternative fuels, new prime movers and energy saving technologies. Together we will take the first steps in the transition to more sustainable dredging vessels.

 

Written by

Benny Mestemaker
Senior specialist New Fuels & Drive systems