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Solid - Oxide Fuel Cells To Save The Hydrography | |
| Sumita Pawar |
IDTexhEx reports say that the chemical energy in green fuels can be turned into mechanical energy in a number of ways, including combustion. However, fuel cells have a lot of potential as a highly efficient solution that could lead to zero emissions.
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Between batteries, fuel cells, green hydrogen, green ammonia, e-methane, and carbon capture, it might be fair to say that more than one solution is coming to light. This is because decarbonizing all marine sectors might be possible.
IDTechEx thinks that green fuels are one of the best ways to get large ships off of fossil fuels.
Currently, there are only two options for fuel cells in the marine environment: proton exchange membrane fuel cells (PEMFC) and solid-oxide fuel cells (SOFC).
The new IDTechEx report, "Fuel Cell Boats and Ships 2023–2033: PEMFC, SOFC, Hydrogen, Ammonia, and LNG," looks at the latest FC technologies and materials. It shows that the green hydrogen PEMFC and LNG/green ammonia SOFC markets will grow at a CAGR of 35% over the next ten years.
According to the report, PEMFC is the most commercially available and the focus of most suppliers, whose focus is hydrogen. Hydrogen has a volumetric energy density of 8.5 GJ/m3 as a liquid (–253 C), with the bar set by diesel at 33 GJ/m3 (STP).
As a further report added, SOFCs solve many of these pain points. They are fuel flexible and can be operated with ammonia, hydrogen, LNG, LPG, methanol, ethanol, and more at efficiencies of >80% with combined heat and power (CHP) processes.
This is a large increase over typical PEMFC and marine diesel engine efficiencies of 55% and 45%, respectively.
Liquid ammonia is an attractive fuel choice by many metrics. It has an energy density of 12.6 GJ/m3 (–33.5 C), which, with 80% SOFC+CHP efficiency, results in onboard storage requirements much more comparable to diesel.
At –33.5C, ammonia is easier and less energy-intensive to liquefy and store than LNG and hydrogen, at –161C and –253C, respectively. In fact, fossil ammonia today is already traded in large volumes by sea for the mining and fertiliser industries.
Most importantly, ammonia, which is made up of nitrogen and hydrogen (NH3), is a way to stop carbon and methane from being released into the air.
The advantages of ammonia and ammonia-fed SOFC+CHP are naturally generating industry excitement.
Yara will supply green ammonia, allowing up to 70% of the power requirements to be zero-emissions.
So, what is the question? There are some commonly cited technical disadvantages for SOFC, including long start-up times and poor dynamic response (a result of 800 °C operation).
However, IDTexhEx reports that these issues are manageable in the marine environment when combined with a battery system and the use-case of long voyages at sea (long, continuous operation). The primary drawbacks are simply that mega-watt SOFCs and green ammonia are not readily available today.
Overall, batteries and hydrogen and ammonia fuel cells have high potential to create long-term pathways to zero emissions. It is simple to imagine a future in which hydrogen PEMFC and batteries are widely used in the mid-term and ammonia SOFCs are widely used in the long term.
The report concludes that lowering emissions in the maritime sector will continue to rely on tremendous investment, financial support, and policy drivers from both the public and private sectors.
By Sumita Pawar