With climate change concerns front of mind, the world is desperate to get to net-zero carbon output as soon as possible. While direct electrification is becoming popular for regular passenger cars, it’s not yet practical for more energy-intensive applications like aircraft or intercontinental shipping. Thus, the hunt has been on for cleaner replacements for conventional fossil fuels.
Hydrogen is the most commonly cited, desirable for the fact that it burns very cleanly. Its only main combustion product is water, though its combustion can generate some nitrogen oxides when burned with air. However, hydrogen is yet to catch on en-masse, due largely to issues around transport, storage, and production.
This could all change, however, with the help of one garden-variety chemical: ammonia. Ammonia is now coming to the fore as an alternative solution. It’s often been cited as a potential way to store and transport hydrogen in an alternative chemical form, since its formula consists of one nitrogen atom and three hydrogen atoms.However, more recently, ammonia is being considered as a fuel in its own right.
Let’s take a look at how this common cleaning product could be part of a new energy revolution.
A Clean Burn
Like hydrogen, ammonia is flammable. It also contains no carbon, so it doesn’t produce carbon dioxide during combustion. It has much better energy content by volume, almost double that of hydrogen, though only a third as much as diesel. It’s also much easier to store than hydrogen; it is liquid at just -33°C, compared to liquid hydrogen that must be stored at -253°C. Plus, ammonia doesn’t have the same storage problem as hydrogen, which can creep out through tiny gaps in almost any material, often damaging them in the process.
The concern is around getting this fuel cleanly. Currently, ammonia is made using the Haber-Bosch process, which combines hydrogen and nitrogen to make ammonia. Fossil fuels are typically used as a source of hydrogen. In a process called steam reformation, methane from natural gas is turned into hydrogen, but the process comes with significant carbon dioxide emissions. In fact, ammonia production currently makes up about 1% of global carbon emissions.
Green ammonia is the solution, where the hydrogen is instead supplied in a cleaner fashion. This typically involves using hydrogen that is generated by splitting water with renewable energy sources like wind power or solar power. This allows the production of ammonia with far less carbon dioxide emitted, which would otherwise ruin its potential as a cleaner fuel.
For Shipping
The shipping industry is responsible for 2.5% of global carbon dioxide emissions. Efforts have long been trying to reduce the emissions footprint of shipping across the board, and ammonia could be the latest tool in that fight.
Unfortunately, ammonia’s unique combustion properties mean that it’s not a drop-in replacement for existing marine fuels. These typically include diesels and heavy fuel oils used to run giant, low-speed reciprocating engines, though liquified natural gas is becoming popular as a slightly greener alternative.
Thus, efforts are being made to develop marine engines that can use ammonia as a fuel. MAN has developed a two-stroke marine engine that runs on ammonia, and plans are already in place to use the engine to power tankers as well as bulk carriers and container ships. The company is working on a retrofit package to allow older ships to run on ammonia, too.
Ammonia does present some unique challenges outside of the engine itself, too. Thanks to its lower energy density compared to diesel, a ship that would conventionally use a 1,000 m3 fuel tank would instead need 2,755 m3 to go as far using ammonia instead. However, it still beats out hydrogen or batteries as potential options, which would require 4,117 m3 and 14,000 m3 to store the same energy respectively.
As with most new fuels, there’s also the problem of infrastructure. Few to no ports currently offer bulk ammonia as fuel, and it’s not really practical to send your ship’s mate down to the local supermarket to pick up thousands of bottles of cleaning product to run the engine. However, if ammonia engines work well in practice, there’s every chance it will catch on, and for the shipping industry to begin a push towards mainstream use of the cleaner fuel.
For Power Plants
Japan is exploring the use of ammonia as a co-burning fuel for coal power plants. The intention is to add 20% ammonia content by calorific value to fuel in these plants in order to reduce carbon emissions. As with many other cleaner fuel projects, starting with a blend is less technologically challenging, and also eases the pressure on supply chains. The technology will go into testing in 2023, and it’s hoped the 20% blended fuel will be ready for practical use by 2025. In the longer term, it’s hoped 100% ammonia combustion could be used for power generation, but that goal is set for 2040 or beyond.
A zero-carbon fuel for power generation would be a useful tool to back up renewable sources of energy that aren’t available around the clock. However, ammonia combustion does still create nitrogen oxides, and thus it’s not as clean as options like solar and wind power.
Using ammonia for power generation will increase Japan’s demand for the chemical significantly. Japan only used 1.1 million tons of ammonia in 2019. To meet the goal of 20% co-combustion with ammonia, set for the mid-2030s, Japan would need 20 million tons of ammonia a year. That’s approximately the total amount of ammonia currently traded on the global market, so simply buying more isn’t an option.
Plans are in place to scale up to 3 million tons in the domestic supply chain by 2030. Intentions are to push that up further to 30 million tons by 2050. Much will likely be imported from overseas, with industry exploring options to build new terminals to ship in hundreds of thousands of tons a year by sea.
Looking To The Future
If ammonia is to catch on as a cleaner fuel for the future, several dominoes must fall in its favor. Massive production facilities must be rolled out to produce ammonia cleanly and from renewable energy sources. Storage and shipping infrastructure must follow, and the fuel’s performance must be borne out in the real world. It would also need to be cost competitive with renewable energy options like direct electric from solar and wind, which is a difficult call in the grid power space.
However, humans feel familiar and safe when it comes to burning fuels for energy, and there are great practicalities to liquid fuels that alternative solutions are still yet to match. Ammonia could thus turn out to be a star in humanity’s march to a cleaner energy future.
Banner photo: “Osaka Japan” by Pedro Szekely
I have worked on anhydrous ammonia refrigeration systems, i dont envy the guys that would have to work on these systems.
God forbid any of these systems develop a leak.
Used to work at a reprographics shop in the summer as a teenager (1985-6) and one of the large blueline machines (very large “copy” machines for blueprints … uses ammonia to develop the image) had an ammonia leak, besides clearing out the entire building it cleared my sinus for about 6 months :-)
Ammonia is terribly toxic to aquatic life, and leaks and off-gassing are basically guaranteed, so using ammonia as a shipping fuel is the dumbest idea in a long while.
Aquatic life toxic . . . japanese food. Oh the irony!
Yes, imagine a leak in the hold of the ship, yikes.
On an RV fridge the coil is either sealed and working or leaking and in need of replacement. There’s doesn’t seem to be any “working on it” other than proper airflow & a heat source.
My father worked ammonia and hydrogen sulfide before there were synthetic refrigerants. He told they used to vent them into the sewer system.
That helped suppress the alligator population down there too!
Sewer systems are an anaerobic breeding ground for organisms that generate hydrogen sulfide, so all the venting does is make sewer lines more explosive than they already are. ;)
Ditto, nasty stuff. I’d take a bath in gasoline before anything with ammonia. Ammonia refrigerant is pretty much only used for supermarket freezers in the long racks, and many of those are being changed out to traditional direct expansion cooling systems (CFCs, HFCs and lately HFOs), hybrid glycol systems or the new kid on the block, supercritical carbon dioxide (R-744).
There’s a few people around the world who are super critical of carbon dioxide… :)
Gotta say this seems to be the first fairly well thought out plan I have seen.
Most people talk about the need to switch to solar/wind but ignore those don’t have on-demand production. Using the power generated to produce hydrogen through electrolysis, while it may have loss, seems like a decent way to store the generated energy. Especially if that produced hydrogen is then converted straight to ammonia. Lets be real, trying to store solar/wind in batteries has numerous issues.
Japan easing into it instead of jumping straight in also seems very prudent for widespread adoption.
I look forward to seeing the results of this.
…And guess what is one of the biggest problems in the supply line right now? We don’t have enough for fertilizer. Better start pissing in a barrel, it’ll be worth money in a couple years! Hahahahaha they’re gonna make us all serfs
Well all (most) toilets lead to a treatment plant, I wonder how difficult it would be to “harvest” ammonia from the urea in the waste water?
Forgot to mention: Haber-Bosch process uses mostly petroleum byproduct inputs. They mentioned that above (very briefly) but we’re basically back at the issue of producing hydrogen fuel without carbon LOL
Very true, but that isn’t insurmountable or all that important in this case – the idea clearly being in the end it is nothing but a potentially easier and safer method of moving the stored chemical potential around than hydrogen.
Also it is possible to get carbon neutral hydrogen sourced from plant rather than oil sources as well as splitting water – doesn’t have to be without carbon to be useful, just without adding lots of it..
Yeah have fun scaling that up. Could split the water with nuclear… Could desalinize too. But the secret is that none of this is really supposed to work, it’s supposed to make money off of eschatology and fear. Hence it has to be new stuff (full of hidden pitfalls) instead of proven stuff (with known and manageable pitfalls).
It’s a level of brinksmanship that reaches unprecedented levels of chutzpah. It’s like the guy in the desert dying with water still in his canteen.
You scale up your renewable generation enough to not need a baseload there are certain to be massive oversupply spikes – scale up one and the ammonia/hydrogen generation potential goes up to!
You can make carbon black from natural gas, thus eliminating the grossly poluting way it’s made overseas and it’ll yield hydrogen as a byproduct. The hydrogen in turn can be made into ammonia. I have to think commercial use of natural gas in this way is a big win. See monolith-corp.com
When combined with conventional power plants and industrial processes, this could become a viable solution for dealing with the RE energy storage Duck Curve problem. When your over producing with Solar, Wind and Wave energy you can store the power as liquid Ammonia for use later. the energy density is higher then any battery chemistry to date. add to this flu gas scrubbing to recover valuable industrial compounds and we have a viable option for clean power day and night.
“It has much better energy content by volume, almost double that of hydrogen, though only a third as much as diesel.”
Maybe burn diesel more efficiently.
https://youtu.be/UF5j1DvC954
“… the world is desperate to get to net-zero carbon output as soon as possible.”
Really?
Doesn’t feel that way when we look at all the boomers not cancelling vacations out of desperation.
A vacation isn’t going to affect squat. Same with cars.
This article gets it right, shipping is a huge source of pollution that should be addressed before the miniscule.
Excellent, when the ammonia tanks rupture in an accident. Everyone dies… horribly. Think I’ll pass.
The stuff gets moved around regularly as it is anyway – it can be handled perfectly safely, and accidents have happened – they can be dealt with as long as your emergency responders know how.
Plus should an accident occur its going to be nasty no matter what type of energy storage medium it is, ammonia isn’t unique there, nor would I say really worse. Not that I’d want to be near such an accident, but then the same is true for most industrial chemical and fuel sources, of which huge volumes are shipped around continuously. Some will be nastier than others to be near, but nobody should want to be close to any of them in an accident!
There’s a difference between a few large scale industrial users plus some domestic use in tiny quantities, and everyone using it as fuel with a million more places for it to spill into the environment in large enough quantities to poison people and animals.
Plus, it’s a great way to create more NOx pollution and smog.
https://en.wikipedia.org/wiki/Ammonia_pollution
You obviously have to use it correctly – but ammonia and ammonia compounds are already in use by just about everyone everywhere for so many things, way way way more than enough to do the poison everyone routine if you assume mass scale suicidal tendencies. But that doesn’t happen because almost everyone just knows how to handle and deal with it, doesn’t want to kill themselves and the odd mistake and accident is not enough to matter to the wider world.
And I’m not at all suggesting everyone should be using it locally – what is the point of that! All that does is reduce burn efficiency (quite likely by a vast amount), reduce the exhaust cleanup quality while vastly increasing the costs of cleaning up the exhaust gas at all, and increase transport costs for no good reason in most cases. There are places that will need to use locally, and areas it makes a good enough retrofit to keep expensive older hardware running longer as the replacements slowly get built. But that is a far cry from expecting a mass suicide attempt by pushing for it to suddenly be put into very leaky tanks, with no safeguards as the fuel of every Backup generator, vehicle, and replacing every battery large enough to do so.
If it’s supposed to be a fuel substitute, then what’s the point if you can’t use it everywhere? For the few places you can reasonably do it, it’s either not powerful enough as a fuel, or better substitutes are available such as biodiesel.
Doesn’t need to be everywhere – its an ideal power station fuel, as nobody cares how big those and their fuel storage get, they just want electric. As long as you keep up the required inspections and maintenance it makes a huge deal of sense for cargoships as they can take the loss of a tiny bit more internal volume for the cleaner and easy to produce but lower energy density fuel.
Just because its not the ONE perfect fuel for every situation doesn’t mean anything – by that argument natural gas, petrol, coal, nuclear, diesel, marine oil (etc) are all rubbish for competing against each other and being less ideal for some usecases.
Regardless of the energy use, we will have to figure out green ammonia either way, due to it’s use in fertilizer.
Despite the potential for explosive abuse, I’d still prefer they stick mostly to ammonium nitrate rather than ammonia.
Meanwhile our planet tries to enjoy the increased CO2 while it lasts…
https://youtu.be/BgTdljY7p90
Meanwhile everyone on this planet will continue to take a casual approach to this newly realized little problem we are just now acknowledging. And we will fail because we choose to focus our efforts on CO2 which is not the big bad monster causing our problem. Nope we MUST address the problem of generatingn too much CH4 or methane. Ah, but the #1 producer of methane are cows. We absolutely must reduce the world population of cattle at any given moment, if we realistically wish to save our planet!
Cows huh?
https://youtu.be/2PGV8fAyIrE
Yes, which is why we should try to eat them all!
Water vapor is by far the most potent gas in the atmosphere capable of absorbing/emitting in IR band (badly called “greenhouse gas”). The more humidity, the better transfer of heat, the more clouds. Imagine the repeat of the Eocene climate – green Sahara, moderate climate in Antarctic, the tropics not hotter than now.
Methane is a worse greenhouse gas, and well worth reducing but the orders of magnitude difference in human related releases of the two relegate it to being rather less important – reductions absolutely should be part of the big picture plan for the future, but very little methane is really released by human related activity – as we would far rather burn it for fuel, or failing that just burn it anyway.
The cows are a minor problem, if they are even really a problem at all – you eat vegan and your personal gas production up and with humanity not being a herbivorous species by design the amount of food you need to consume goes up to counter the very much less complete digestion. Then factor in land area and land quality requirements – you can’t grow crops (at least in a havestable fashion) on a great deal of the land area available but livestock can be grazed there no problem, and by being grazed there create/maintain potentially very diverse and stable little ecosystems.
Its a complex web of interactions. But the problem isn’t really the Cows, its the vast quantity of food waste and excessive consumption of humanity as a whole often compounded by rather disjointed and poor farming practices (note not blaming the farmers – they have to earn enough to keep going, and be legally allowed to sell their crops. They can’t control the wider system that pushed them to do x,y,z to stay afloat).
I’m sure details can be ironed out, but it seems to me that burning ammonia would produce: water (ok), oxides of nitrogen (bad), N2 (ok), and various forms of partially combusted ammonia (bad), including pure ammonia (bad). I’d feel much safer driving with a tank of flammable gasoline or hundreds of KW of LiIon cells compared with a tank of ammonia. Same with refueling: gasoline or electrons seem safer in comparison.
Ehhh partially/non-combusted ammonia vs carbon monoxide … At least I can smell ammonia
+1
CO turns into CO2 rather quickly. The ammonia pollution is worse.
Properly burnt with excess oxygen, the products of ammonia combustion are, essentially, water and N2. If it’s to be used as a fuel, research will need to be done to make it easier to burn. Despite the great thermodynamics (very exothermic reaction! Used as fuel in the old X-15), the kinetics—rate of the reaction, ease with which it starts and propagates—will need investigation.
Ammonia is produced as waste by many farm animals. I wonder if that could be captured and used. Likely only enough is produced for use around the farm or ranch.
How to collect the urine? Could evert the teat cup from dairy machinery and insert it, thus making a milk nurse into a cow’s pee-er. … or yeah, just recover from drainage.
Urea is much safer, installations using ammonia would have to be very careful about what metals they are using otherwise there is a risk of the rather energetic tetraamine copper nitrate forming.
ammonia: more hydrogen than hydrogen.
Interesting idea, if Japan is going to be importing tanker loads of ammonia on a regular basis then it would make sense for those tankers to burn ammonia, which would per say be available at the ports at both ends of the trip as well as bought cheaply in bulk. This would be a good way to escape the chicken/egg problem of introducing a new fuel.
Where do you get the hydrogen to create the ammonia? Currently, we get the hydrogen from oil and gas extraction. If you tried to get the hydrogen from electrolysis, it would be SUPER inefficient. So the question remains, how do you sustainably create ammonia? If we can’t answer that, what good is creating engines that can run on ammonia?
This is where Nuke power will be useful, the heat from atomic reactions can split water easy enough.
That’s the only type of hydrogen fuel production I would ever consider scalable. And get right into the idea of moving nuclear from just electricity production to a source of process heat as well. Molten salt reactors
I would say that if the energy is surplus, it doesn’t matter if the process is inefficient. Like trying to improve the efficiency of solar cells – why? Sure, niche cases, but my roof is big enough that solar cells at their current level of efficiency produce ample (and indeed excess) energy.
I see trying to improve efficiency has more benefits in respect to spin-off technologies rather than solar cell efficiency gain directly.
Anaerobic bacteria makes the hydrogen to create the ammonia, but it’d be in hydrogen sulfide form.
The “thousands of bottles of cleaning product” from the supermarket would get you ammonia solved in water. Not the best fuel for a combustion engine…
Here in farm country, ammonia tanks sit in fields and are moved about on highways all the time. Transportation is not that big of a deal.
“With climate change concerns front of mind, the world is desperate to get to net-zero carbon output as soon as possible.”
Except in China and India, of course.
https://i2.wp.com/www.powerlineblog.com/ed-assets/2021/07/IMG_4607.jpeg
This isn’t a renewable and it _is_ a bona fide poison. So this is trading off a smaller carbon footprint (maayyybe) for what?
Have we really reached the limit of what is possible in cleaning up “fossil fuel” extraction? Ask yourself: ships are burning the dirtiest of fuels. Why? Because it’s cheap. And if they are moving to ammonia it’s … because it’s cheap. Why not force their hand to use cleaner burning fuels and engines? Follow the money here. Who stands to profit? 99% certain it is neither the environment nor you and I.
Arguably it is renewable, and you can’t keep extracting and burning yet more buried carbon forever and magically ‘clean it up’. Its continually adding more greenhouse gas than the ecosystem is able to deal with – everything in nature is all set up and evolved for the preindustrial levels, yet we keep pouring more long sequestered carbon on one side of the scale while burning and ripping up much of the carbon sinks of nature and evolution, being a rather slow process can’t hope to keep up.
Forcing everyone to use cleaner burning fossil fuels doesn’t change that equation, all the cleaner burn does is reduce acid rain and particulate problems, might help improve efficiency at the engine (though far from certain), but all the extra refinement and even greater extraction rates required to create cleaner burning fuels will offset that easily. So it does nothing for the overall global problem of excess greenhouse gas creating a massively unstable and potentially rather lifeless planet.
Ammonia on the other hand is a usable, stable, transportable fuel that doesn’t require adding any extra carbon to the ecosystem. It can be made in a carbon heavy way but it doesn’t have to be – Its quite easy to scale up massively and produce via electrolysis for instance. Which can’t be said for biofuels, as scaling them up is substantially harder than finding water and nitrogen. As much as battery tech and fuel cell tech is improving and should be used in some places over this neither can fill all possible needs yet or in the near future where Ammonia is a much more direct substitution – which makes it a very viable and sensible direction to go, at least for now.
Also most things are poison in high enough concentrations, at least this one the natural world is actually quite good a processing once its concentration drops some – so it won’t be as persistent in the event of any leaks.
There MUST be a better word than decarbonize. Suggestions?