Shipping industry needs an alternative to fossil fuels, but which one?

April 9, 2018, University of Manchester
Credit: University of Manchester

The shipping industry needs to move to renewable and alternative fuels to reduce the sector's impact on the environment.

But there is no widely available fuel to manage climate change and local pollutants according to a recent study by researchers at The University of Manchester.

How the 's need to radically reduce its CO2 emissions will a prominent discussion when the International Maritime Organisation's Marine Environment Protection Committee (MEPC) meets in London from 9-13 April.

The research team says there is a need for alternative fuels in shipping for two main reasons; to reduce local pollutants and comply with regulation and; to mitigate against and cut greenhouse gas emissions.

Alternative fuels are defined as any other fuel than conventional fossil fuels that can be used for powering ships. The alternative fuels assessed in the study were liquefied natural gas (LNG), methanol, liquid hydrogen (LH2) (with and without carbon capture and storage), biodiesel, straight vegetable oil (SVO) and bio-LNG.

However, the analysis demonstrates that no widely available fuel exists currently to both reduce the environmental impact and comply with current environmental regulation. Some of the alternative fuel options analysed have the potential, but only if key barriers can be overcome.

Dr. Paul Gilbert, Senior Lecturer in Climate Change Mitigation, said: "There is, at present, no readily available fuel option to deliver significant savings on local pollutants and greenhouse gas emissions in tandem. In particular, LNG is a promising option for meeting existing regulation, but it is not a low greenhouse gas emissions fuel."

Researchers from the University's Tyndall Centre for Climate Change carried out a life cycle assessment of current and future fuels used by the shipping companies to quantify their environmental impacts.

They measured the impacts by using six emissions types. These were local pollutants (sulphur oxides, nitrogen oxides, and particulate matter) and greenhouse gases (carbon dioxide, methane, and nitrous oxide).

However, to become a viable alternative for the industry to adopt, the fuel must meet a range of criteria. One of the fundamental requirements is that it can deliver emissions reductions over its full life-cycle.

Dr. Gilbert, from School of Mechanical, Aerospace & Civil Engineering, added: "To understand the full extent of the environmental implications it is important to consider the emissions released over the full life-cycle and not just during fuel combustion. Otherwise, there is a risk of misleading the industry and policy on the true penalties of any ."

The study says effort needs to be directed at overcoming barriers to exploiting the identified low carbon potential of fuels, or finding alternatives.

Dr. Gilbert said: "As the urgent need to curtail gas emissions is the more severe challenge, it is therefore important to ensure that any short-term measure doesn't diminish the potential roll-out of low carbon fuels, in particular when taking into account the long life times of ships and supply infrastructure. To meet the objective of reducing , whole life-cycle emissions need to be accounted for."

The paper "Assessment of full life-cycle air emissions of alternative shipping fuels" was published in the Journal of Cleaner Production.

Explore further: Fiat Chrysler and Eni cooperating on emissions reductions

More information: Paul Gilbert et al. Assessment of full life-cycle air emissions of alternative shipping fuels, Journal of Cleaner Production (2017). DOI: 10.1016/j.jclepro.2017.10.165

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5 / 5 (1) Apr 09, 2018
3 / 5 (2) Apr 09, 2018
However, the analysis demonstrates that no widely available fuel exists currently to both reduce the environmental impact and comply with current environmental regulation.

Hydrogen? I know it's not as energy dense, but I could envision mid-ocean wind or solar parks that create the stuff as refueling stations.
not rated yet Apr 10, 2018
They tried the liquid hydrogen, one of the major problems there is storage being operated by non-specialized technicians, standard boat mechanics, and they are not up for the challenges of hydrogen storage. That is one of the biggest problems concerning the use of hydrogen, the fact that it is very hard to contain and will seep through most materials slowly, and can force cracking easily. Liquid Hydrogen is a nasty material to be using in the field, let alone that we do not have the infrastructure in place for it yet.

Going back to sails and solar makes the most sense to me. People depended on sails for thousands of years. Yes, the motorized ocean going ships have regularized trade, sped up the distribution of items, but there is still a lag between producer and market due to the shipping pipeline. Wind may make that pipeline a bit longer, but augented with heavy use of solar tech, there should not be That much of an increase to shipping time, and would cost less due to no fuels
1 / 5 (1) Apr 10, 2018
They tried the liquid hydrogen

There are alternatives to liquid hydrogen (e.g. metal oxide frameworks).
Liquid Hydrogen is a nasty material to be using in the field

I don't think so. Plenty industrial companies use it every day. While I don't think an infrastructure for e.g. personal transport could be set up in a reasonable time frame the issue for shipping (or air travel) seems feasible. Sea and airports have sufficient space and the infrastructure is not overly complicated (Particularly since the stuff can be created in situ as long as you have a power connection). There are also not that many of them that handle international shipping/air travel.
For national/continental travel battery powered planes seem within reach with the next generation of batteries (e.g. lithium-air) and the first battery powered ships for short haul routes are already operating.

Sails and solar aren't plannable. Shipping today requires sticking to timetables.
3 / 5 (2) Apr 10, 2018
As for solar on ships in general. Let's take a ship like the Emma Maersk class container ship.

It's 397 meters by 56 meters (length, beam...for simplicity's sake let's say it has a rectangular surface area of roughly 22000m^2 )
If you plaster this with 100% efficient solar cells and assume every day perfect sunshine (1kW per square meter) ....and then take into account that a 1kW rated solar panel produces on average about 4.5kWh per day (I used the numbers for Australia, since that seems to err on the cautious side if anything). Then you are getting an average energy yield of around 100MWh per day. With a bit of buffer batteries you spread this over 24 hours operation giving you a rough 4,2 MW of available engine power.

Now the *real* engine power of something like an Emma Maersk class cargo ship is 81 MW. So you can see solar - even at such stupendously optimistic conditions - isn't going to get you anywhere in shipping.
not rated yet Apr 10, 2018
a_p: yeah, solar is right out.
One size does not fit all. For some classes of cargo, sail power as a primary or supplemental propulsion system might work fine.

I'm surprised we don't see some sort of synthetic fuel option along with bio fuels.
3 / 5 (2) Apr 10, 2018
I'm surprised we don't see some sort of synthetic fuel option along with bio fuels.

In shipping it all boils down to cost. The oil burned in ship diesels is the lowest of low qualities, because it costs next to nothing. Currently the price is at roughly 133 dollars per metric ton...which equates to around 0.5 dollars per gallon.
There's no way biodiesel can compete with that. There's about a factor of 5 between them and I see no way that biodiesel could be made that much cheaper.
1 / 5 (1) Apr 12, 2018
There are alternatives to liquid hydrogen (e.g. metal oxide frameworks).

MOFs are barely better than batteries, because the amount of hydrogen per mass they store is very small.

And the issue of hydrogen leaking is still very real - it leaks, mixes with air, and causes large explosions very easily. Powerplants use hydrogen as a coolant for turbogenerators because of its excellent thermal properties, and accidents involving hydrogen re-filling happen every so often.

People assume hydrogen just rises up the sky safely, but in reality it diffuses into air and loses its buyouancy, and you're left with a lingering cloud of explosive gas.
1 / 5 (1) Apr 12, 2018
Easy. Either rossi LENR or mills hydrino. Or both. Otherwise weve hit a wall.
not rated yet Apr 12, 2018
All this quibbling over little details about another 10 or 20 percent this way or that... we need magnitudes more power per capita in order to survive. We need magnitudes more if we are to begin cleaning up this planet before we won't be able to live on it any more.

We need to be able to transit to and from mars the same way we cross the Atlantic. We need machines that can essentially run forever. And this has to happen in the same timeframe as electricity or internal combustion.

And the only possible solution out there are these exotic improbable sources. Batteries will never run robots that we can use. Neither fusion nor fission will cut it. And we need robots to begin fixing the mess we've made, scouring the environment, fixing the ecosystems.

Things are way past the point of fixing themselves.

And so we had better hope that Rossi or mills or someone else is working on the source of power we desperately need, the only thing that will save us from extinction.
not rated yet May 23, 2018
I could envision mid-ocean wind or solar parks that create the stuff as refueling stations.
Things are getting so bad in some parts of the ocean that I keep thinking of ships powered by plastic harvested from the sea. Sort of an ocean going version of a Bussard ramjet...

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