Hopefully this ship of fools runs aground before it kills its whole crew with the first, inevitable, leak.
Ammonia is also lighter than air. When it is first released it is typically cold, so it sticks around until it warms up. Eventually it will float up into the atmosphere.
One disadvantage is its lower energy density, you need to store twice as much of it as bunker oil.
One advantage that I can see for Ammonia is that the ingredients it is composed of are readily available from the environment. Also, the fuel may be upgraded by cracking it into hydrogen and nitrogen using waste heat from the engine. Hydrogen gives a bigger pop in the cylinder, Ammonia doesn't burn as easily.
One scenario I can think of is using nuclear power on a platform in the ocean, manufacturing the Ammonia, ships can come by and refuel there.
That’s a red herring. Getting hydrogen and nitrogen out of their naturally occurring forms (bonded to other things or to themselves) and turning it into ammonia is very energetically intensive.
> One scenario I can think of is using nuclear power on a platform in the ocean, manufacturing the Ammonia, ships can come by and refuel there.
I can think of many such scenarios if money is no object.
But as you say, they currently run on bunker fuel which is essentially garbage. You have to pay people to take that of your hands. It is being ridiculous to think that they would switch, on their own dime, to burning ammonia. And green ammonia at that which is orders of magnitude more expensive.
Who is willing to pay the resulting shipping costs?
Synthesizing hydrocarbon analogues of fossil fuels (petrol, kerosene, diesel, bunker fuel[1]) is possible and has been theoretically demonstrated.[2] The problem is that it's not economically feasible, in large part due to structural market failures in the price of petroleum.[3]
Physical abundance of the constituent elements has little to do with production costs of the resultant fuel.
And hydrocarbons are vastly preferable to ammonia as fuels for all kinds of reasons: energy density, noncorrosive nature,[4] non-toxicity, convenience in general handling and storage, etc., etc., etc. So long as you're synthesizing fuels, make it the good stuff, not poison.
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Notes:
1. That last is probably a non-starter. It's harder to synthesize longer-chain hydrocarbons, so far as I'm aware, and the primary driver of bunker oil for marine propulsion is that it's an otherwise low-value surplus from conventional petroleum production, even a large fraction of much extraction, e.g., Venezuela's very tarry petroleum,and Canada's tar sands. Lighter fractions would be easier to synthesize and more attractive as fuels.
2. For about 60 years, including research at Brookhaven National Labs, M.I.T., and the US Naval Research Lab, as well as with a Google moonshot project. A list of sources is here: <https://news.ycombinator.com/item?id=28970111>
3. A deep topic, but given the fact that we're extracting petroleum at roughly 1 million times its rate of formation, and in a highly unsustainable fashion, there's a fair argument that petroleum ought to be priced about 1 million times its current market price. The economics of nonrenewable resource extraction is grossly irrational and divorced from physical and geological realities. On rates of formation, Jeffrey S. Dukes, "Burning Buried Sunshine" (2003) <https://core.ac.uk/download/pdf/5212176.pdf> (PDF). Previous discussions: <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...>
4. Indeed hydrocarbons are routinely used as lubricants and protectives for metals and other materials.
Like anything else, risks can be mitigated.
The main concern for me is at dockside where there are lots of people nearby. Ideally I think they'd "lock down" and depressurise the ammonia system (except the storage tank) when close to port, and only bring it online when out at sea and far from population.
Also the refuelling process seems a bit risky. But these things are already quite routine; ammonia is already a large-volume industrial commodity with well-developed controls.
And many options exists that are less inherently dangerous than ammonia. Like methanol. At least it’s a liquid and not nearly as bad.
But ammonia is chosen as a predatory delay strategy. They build the engines to be dual fuel (ammonia and methane) and then feign surprise when they have to run it on methane since the ammonia supply chain “isn’t ready yet” and the prices “need to come down a bit”.
1. https://library.sciencemadness.org/library/books/ignition.pd... 2. https://en.wikipedia.org/wiki/Chlorine_trifluoride
Ammonia is being pushed as a predatory delay strategy. The article hints at this when it talks about the engines being dual-fuel (ammonia and methane). Given the massive price difference between green ammonia and methane it doesn’t take a genius to know what their next message will be “our ships are ammonia ready, we will run them on methane until the ammonia supply chains are ready then we’ll transition to it”. Expect they have no intention of transitioning.
The ships are “ammonia ready” in the same way my driveway is Ferrari ready. All that’s missing is a lot of other people’s money.
In the end, gas leaks are always bad. But at least you can easily smell an ammonia leak.
IIRC, they add a very nasty smelling chemical to LNG so that leaks are evident before they get explosive. In the case of ammonia, the additive is not really needed, and the toxicity being much higher makes me think that, by the time you realize you are breathing ammonia, it's already too late.
Would be interesting to know if its commonly added to industrial LNG. Because we burn a lot of that - even if you only add a few ppm thiol to natural gas, that's a whole lot of sulfur being burnt...
I'm not sure how likely fire is in case of a leak.
Hopefully in a deserted rock in the middle of nowhere.