MAN Energy Solutions to offer #ammonia-fuelled ship engines after 2027.
Also:
"On Friday, MAN Energy Solutions opened a 20 million-euro ($21.6-million) workshop in Singapore, its largest outside Europe, to maintain, repair, and retrofit fleets using its dual-fuelled engines that can burn oil and alternative fuels such as liquefied natural gas and #methanol."
#Ammonia is highly toxic, so spills could be a disaster. Then there's the NOx emissions from burning it. But right now there aren't a lot of options for propelling ships that don't emit CO2.
Also there may be a lot of ships carrying ammonia in their holding tanks soon, if the hydrogen people get off the ground. Ammonia is the way to ship hydrogen long distances.
@CelloMomOnCars Why would you want to ship hydrogen long distance? Even as ammonia, it's probably easier to make it locally. Unless white hydrogen pans out, which seems unlikely. Large scale grid connections are necessary and lose very little power, and there will be surplus renewables often enough.
Of course that's assuming that we find a solution for low load factor green hydrogen; current electrolysis has difficulty below 50% load, and every time you start/stop it there's a leak into the atmosphere.
Also assuming that hydrogen is mostly used for 1) industry, 2) shipping and 3) possibly long term grid connected electricity storage. Though the last is frankly doubtful.
Both hydrogen and ammonia are a problem when leaked and produce significant pollution when burned. So burning it is at best a stop-gap; ultimately we need fuel cells. Having said that, the article claims that it's practical to filter out NOx from shipping engines; an interesting claim given this is one of the main arguments against burning hydrogen for electricity. It looks like a long term project though given the demo was only 8kW!
Long term there may be other options but both iron-air and DARPA's high-density flow batteries are under around 1200Wh/kg, which is fine for grid storage, but 1/5th the density per kg of ammonia (if I've done my sums right; ammonia is around 20MJ/kg). Although DARPA's goal is to eventually be able to use it for aircraft and tanks.
Australia right now gets a lot of income from shipping its coal to China. As that gets phased out it's looking for new sources of income. Exporting hydrogen (through ammonia) made from its abundant insolation is one option.
Same for north African countries, e.g. Lybia.
Hydrogen is not for everything as it's proselytisers claim, but it does have a place where it's hard to find replacement for fossil fuels, e.g. steel making.
A little more so than methanol, but it gasifies at STP. It's a real risk, but a calculable one. (Look up the news for gasoline truck fires; they happen all over America like one a week and we're just like "Yeah, that happens." )
Methanol is my synfuel of choice but that requires a carbon source. Everything's a tradeoff, including gasoline.
@CelloMomOnCars#Ammonia is the perfect choice for marine vessels. I don't think the NOx emission problem is much bigger than it is for Diesel.
NH3 is also a good choice as a chemical carrier for storing and transporting renewable energy - far better than any battery will ever be. The technology for storage and transport already exists as hundreds of million tonnes of ammonia are produced and shipped every year.
The summary is that there is a tradeoff between having too much much NOx (high reaction temperature) vs too much unburnt NH3(low reaction temperature) in the exhaust gas mixture. An NH3 engine will need some form of catalytic flue gas treatment to meet air quality regilations (just like diesel or gasoline engines).
Unfortunately, I have not found a direct comparison between NH3 and diesel engines.
Thanks for the précis, the abstract didn't reveal much about the conclusions (and I no longer have library access to journal papers).
The impression I get: Everyone knows NOx can be a huge problem, there are several workarounds. My own take: If good workarounds are developed quickly it may just save ammonia as a fuel and could even be cleaner than diesel scrubbers. (All that still doesn't do anything about the NO3 toxicity though).
@CelloMomOnCars NOx are a problem with all types of internal combustion engines. The higher the efficiency, the higher the NOx production. However, the technology to remove them exists.
I wouldn't worry too much about the toxicity. NH3 has a strong smell, so it would not go unnoticed. As I said, hundreds of megatonnes of NH3 are already produced and transported everyday w/o major problems. In an industrial environment, NH3 can be handled easily. It is far less toxic than e.g. Silane (H4Si).
@CelloMomOnCars Sure, there will be mishaps. However, NH3 is a gas at ambient pressure and does not easily dissolve in water. So, if there is a spill, most of the NH3 would evaporate and be diluted quickly. The main danger would be from fire.
Oil tankers pose a far greater environmental risk than NH3 or LNG tankers.