Could we power the largest ships with seawater?
In this article I ask the question, “Could we
actually power every ship in the ocean via the sea water that surrounds them?”
Although I find it an interesting question, there’s
no doubt plenty that might think it to be a far fetched question. The thing is though; we are only now just
scratching the surface of Hydrogen fuel.
It’s an extremely promising option for decarbonizing the shipping
industry and I’m excited at the prospect of it. As burning hydrogen in fuel cells does not
emit any greenhouse gases, building ships that would be powered by Hydrogen
might just fix a lot of things on this planet.
There are approximately 58,000 merchant ships in
the world, 5,600 of those are massive container ships and there are around 450 monstrous
cruise ships. There’s got to be over 5,000
naval vessels in the world too. I did a
bit of creative guessing and think that the daily diesel burn for ocean going
vessels in the world would have to be over 3,500,000 tonnes of diesel per
day. When I started looking at only
vessels that were over 100 metres in length, I think that daily diesel burn would
come down to 1,700,000 tonnes of diesel per day.
Surely when we combine this daily diesel burn with
every road going diesel engine vehicle in the world, there’s a good case at
looking for better ways to power the ocean going vessels of the world.
Especially if there’s even a remote chance that we
could power them via the sea water that surrounds them.
However, producing hydrogen fuel from seawater is never
going to be easy or cheap and the truth is that this might be one thing that
proves to be too difficult to implement.
The two primary processes for producing hydrogen
fuel from seawater are thermochemical conversion and electrolysis. Using an
electric current, water molecules can be split into hydrogen and oxygen through
a process called electrolysis. Hydrogen can be extracted from water through a
process known as thermochemical conversion, which uses heat and chemical
reactions.
Each approach has benefits and drawbacks. Hydrogen
can be produced through electrolysis without emitting any emissions by using
renewable electricity sources like solar or wind power. However, if seawater is
used directly, electrolysis can produce chlorine as a toxic by-product and
needs a lot of energy and water. Utilising concentrated solar power or waste
heat from nuclear or fossil fuel power plants, thermochemical conversion can
create hydrogen with less energy. However, if seawater is used directly,
thermochemical conversion can produce hazardous pollutants and necessitates
high temperatures and complex catalysts.
Therefore, before being widely used for the
production of hydrogen from seawater, both approaches must overcome a few
technical and financial obstacles. Eliminating salt and other contaminants from
seawater is a major task since they can damage machinery, lower production
efficiency, and raise the price of hydrogen. While desalination is a viable
option, it comes with significant energy and water consumption costs and
generates brine as a by-product.
Through the use of unique coatings, membranes, or
catalysts to counteract the effects of salt and impurities, some researchers
have created cutting-edge methods for producing hydrogen from seawater without
the need for desalination. These techniques need to be tested for viability,
robustness, and safety on a larger scale as they are currently in the
experimental or prototype stages.
In conclusion; the concept has a lot of potential
and, while it is not currently a viable or cost-effective option, it may one
day allow ships to run on hydrogen fuel by converting seawater into hydrogen.
Enhancing the efficacy, dependability, and cost-effectiveness of hydrogen
generation from seawater, along with the organisation, conveyance, and
application of hydrogen fuel aboard vessels, requires further investigation and
advancement.
