Not sure this works

Of course, it’ll be market prices that allow us to work out whether it will or not:

Jet engines for passenger planes that can run on environmentally friendly ammonia rather than fossil fuels are being developed in a new venture involving an Oxford-based company and a government agency.

Ammonia produces harmless water vapour hydrogen and nitrogen as by-products rather than carbon dioxide and could help Britain reach its clean air travel aims years ahead of schedule.

The joint venture is being set up by Reaction Engines with FTSE 250 investor IP Group and the state-backed Science and Technology Facilities Council. A spokesman declined to comment on the amount of start-up funding available.

My initial thought is that if you can get to ammonia – presumably via green hydrogen, otherwise what’s the point? – then you can get to jet fuel through chemistry. I don’t know this and am not competent to try to work it out, perhaps someone here knows? But that would be my initial thought.

Put all the effort into the chemistry at the front end rather than try to change the infrastructure of all those thousands of ‘planes and fuel tanks and everything.

35 thoughts on “Not sure this works”

  1. I’m boggled at the idea of ammonia being environmentally friendly. It certainly isn’t if it leaks, and at the temperatures in a jet engine you’re not going to get just H₂O and N₂ as combustion products, you’re going to get NOₓ as well.

  2. Not sure what white-hot ammonia does to turbine blades but the energy content of ammonia is a lot less than kerosene (18.8 vs 46.2 Mj/kg) so that severely affects all other aspects of aircraft design to re-optimise it for cost of ownership, range etc.

    What would be more interesting would be to compare the cost, feedstocks and energy inputs of ammonia production versus synthetic kero.

  3. What is required is to have a way to convert water and (atmosphereic) CO2 into (m)ethanol and then longer chain hydrocarbons that look like current petrol/diesel/kerosene etc.

    Some combination of organic (enzymtic) catalysis and metal (platinum etc.) catalysis should do the trick, presumably with some heat/pressure etc.

    Then you stick this reactor next to a large solar and/or wind farm and have it run when the sun shines/wind blows. The output is the fuel we already have the infrastructure to store/transport

  4. Ammonia has been used as a rocket fuel, and air breathing ammonia engines are very non polluting. The downside is that its energy density per unit volume, although better than hydrogen, is still only one third that of diesel fuel.

    As always with these things whilst it is possible to synthesize “green” ammonia, current production isn’t “green” and amounts to 1.8% of CO2 emissions.

  5. Combustion will never be 100% efficient of course and at takeoff thrust the odour of ammonia, not to mention the mucosal irritation produced in the vicinity of the airport will be a real problem. If you dislike the aroma of Jet-A combustion, imagine that of ammonia. Additionally at Tractor Gent points out, airframe design will need to change dramatically to cope with the fuel thrust to weight ratio, not to mention airport airside infrastructure. Still, if the goal is to stop the public travelling, ammonia will help and Heathrow will make a rather good distribution centre for Amazon.

  6. The whole raison d’etre is that carbon dioxide – that vital gas which plants need for their very existence (like us with oxygen) – is a civilization and planet destroying poison to a degree unprecedented in history. A premise that is utter bollocks of course, as demonstrated by the whole “climate emergency” hysteria, the absolute core of which needs to be lying and misrepresentation, and the way children are targeted – a more graphic demonstration of its degeneracy I cannot imagine.

    Will this work in practice? I don’t know. Will it reduce “carbon”? @SadButMadLad – clearly not!

    The civilization destroyer is not “carbon”, but the pseudo soviet lunacy that passes for government these days. Even by their own lights – reduction of “carbon” – most of their schemes are stupid and self defeating, with milk floats being perhaps the most egregious current example.

    The real problem is the infantilization of the advocates, and depressingly, the increasing infantilization of the general population.

    It doesn’t matter how badly any particular scheme crashes and burns, the infantilized mind is simply incapable of accepting any responsibility. We’ve all had those arguments with children, and the parallels with these “green” lunatics when challenged are striking.

    I do sometimes wonder if the ACTUAL destruction of civilization would penetrate some of these green taliban.

  7. Why on Earth don’t we just say “let’s leave aircraft alone”? If we can stop ground vehicle CO2, and stop domestic heating CO2, surely that will be enough? Cannot the plants deal with the reduced level of CO2 output in the normal way? CO2 is not some evil corrosive racist devil, it’s a normal and natural gas, we just want to be producing a low enough level such that the planet can cope.

  8. I agree with AndyF that we’d be better off just manufacturing our present fuels from CO2 and H2. I do think that nukes are a better way of providing the energy rather than unreliables.

    Of course this means that everyone else has to go to all the bother while I just carry on as usual.

  9. It would be easier to ration everyone to flying a maximum of 3,000 miles per annum. You can always get the train back.

    In fact if they built a decent Chunnel under the Bering Strait making max use of the islands you really could catch the train from London to NYC. Or the bus. At least it’s a better idea than HS2 or that daft Californian high speed railway line.

    Has anyone ever bored a tunnel between different tectonic plates? Better get cracking on the design problems now.

    Alternatively, encourage travel by sea. The journey takes a bit longer but you’ll escape jet-lag and you can do some work on your laptop. If sea travel is good enough for oligarchs on their hols it should be good enough for all of us.

  10. Brainless twattery.

    Aircraft fuel systems are SYSTEMS, not just a tank of liquid. It’s bad enough coping with different blends of kerosene, depending on where you just refueled (A & B values, for the afficionados), so changing to a whole new fuel like ammonia is starting again. Back to 1910.

    – How do you cool the IDGs? You certainly cannot do it with ammonia!
    – Hydraulic properties of liquid ammonia? (fuel systems have ‘hydraulic amplifiers’ under the control of the FADEC to control the fuel flow, using the fuel as the hydraulic medium.)
    – Compatibility of ammonia with light alloys? Silicone seals? Lubricating oils?
    – Toxicity. See my comment about avtur stench in cabin, a few threads ago.
    – How do you store ammonia in long thin wings? Pressure vessels are heavy, strong and fat.

    The whole idea is Upminster.

    NB regarding another comment, read “Beyond Oil & Gas: The Methanol Economy”.
    You can make methanol from the air (and without using vital farmland!) and even better, from another source of CO2 (e.g seawater as per another comment on similar thread).
    You can use the methanol direct, as vehicle fuel, or reformulate into DME as a diesel substitute, or into other hydrocarbons as kerosene and gasoline substitues. Totally net zero.
    (If nuclear powered or unicorn-fart powered).
    But only the elite will be able to afford to fly, since their expense accounts are paid by you.
    Plebs get out and walk.

  11. TtC: The whole idea is Upminster

    Well quite. I’m simply not qualified to explore the entrails of all the “solutions” being proposed by “experts” but to my untrained eye they all owe much to the old technology of the three card trick.

  12. dearieme,

    “Alternatively, encourage travel by sea. The journey takes a bit longer but you’ll escape jet-lag and you can do some work on your laptop. If sea travel is good enough for oligarchs on their hols it should be good enough for all of us.”

    I’m not sure it’s oligarchs on cruise liners. More retired Brummies. The oligarchs might spend time on a boat, but they fly there.

    If you could shave a day off the old record, and have London to NY in a little over 2 days, I’d consider it. I’ve also wondered about this for long distance UK travel. Get on a boat in London and sail up to Edinburgh. Could you do that overnight?

  13. Do you ever wonder if we might be approaching Peak Stupidity on all this? I’ve been looking at the comments under newspaper articles on climate matters. There’s one in the Torygraph today. Was a time that dissenting views would provoke hearty responses for Climate Change true believers. There’s less & less of that.
    Up until now the costs of We Must Reduce Carbon have always been some indeterminate time in the future. And, yes, there’s steep discounts on future money so why shouldn’t there be steep discounts on future pain? They’re both costs. It’s very easy to convince people to buy something if the cost of doing so is deferred. That’s what the credit industry’s about. It’s a lot harder when it’s cash on the nail.
    This has stopped being what people are going to have to give up in some hazy future & dropped into the realm of the intervals that people actually plan their lives on. Banning ICE cars is getting to the choice of the next new car after the one they’re currently running. Heat pumps the next replacement when the current boiler needs replacing. Flights, that trip was being planned to see the son/daughter’s family half a world away or that dream holiday they’ve been promising themselves. It’s all getting very real.
    Maybe the pantomime of COP26 marks the Peak. Doesn’t matter what system it’s being done under, government requires consent. And it’s very hard to get consent by compulsion. Maybe it’s possible in China, but China’s the result of a long history of compulsion.

  14. bis
    Do you ever wonder if we might be approaching Peak Stupidity on all this?
    Fuck no. Too many people having too much fun and making out like bandits. I think there will be a reckoning, but TPTB will keep doubling down until the whole house of cards comes tumbling down in a rush. Should involve lions and Ecksian solutions but it won’t.

  15. bloke in spain,

    “This has stopped being what people are going to have to give up in some hazy future & dropped into the realm of the intervals that people actually plan their lives on. Banning ICE cars is getting to the choice of the next new car after the one they’re currently running. Heat pumps the next replacement when the current boiler needs replacing. Flights, that trip was being planned to see the son/daughter’s family half a world away or that dream holiday they’ve been promising themselves. It’s all getting very real.
    Maybe the pantomime of COP26 marks the Peak. Doesn’t matter what system it’s being done under, government requires consent. And it’s very hard to get consent by compulsion. Maybe it’s possible in China, but China’s the result of a long history of compulsion.”

    It’s best to think of all of this like Christianity. Like, yes, there’s all those tenets of it, and some reasonably good philosophy, but surrounding it used to be a whole lot of virtue signalling and social climbing, groups using it to gain power and wealth, and mad saints.

    Pilgrimage to Canterbury = going to a climate march (showing your commitment to the cause)
    Greta = Joan of Arc or St Bernadette (young innocent messengers of the god)
    Owning a fancy bible = owning an electric car (getting to show commitment and signal your wealth)
    Heretics = deniers
    Penance = plastic bag tax

    You have the minister talking about integrating climate change throughout school, which just makes it similar to people doing multiple prayers per day.

    But none of it means anything and is all loaded with hypocrisy. The woman I know that goes on about “doing our bit” drives an X5 and lives out in the sticks and takes 2 scuba diving holidays. She’s the equivalent of the priest who is going to gay saunas on weekends.

    I’m not too worried about it. If they really try and force electric cars on everyone in 2035, the government will take a pasting. No-one has even started to think about the grid and wiring updates and all the parking spaces required.

  16. So this would exhaust water vapour into the upper atmosphere? Someone’s forgotten what the anthropogenic hypothesis actually says…

  17. I hope BiS is right.
    There is an increasing realisation that all the green stuff is gonna hurt, and soon. Indded, with the recent power prices, it now is. Good.
    Pushback is there. Banning boilers is probably key, helped by a few days-long country-wide power cuts. It’s still a ‘black start’, even if the term is waycyst. I’m hoping Macron will oblige, with an interconnect tantrum.

    No one knows exactly when a ballon will burst.
    But burst it will, and someone will take over the pieces.

    Question is who? A freedom and sound economics ‘Mrs Thatcher Mk2’, or a ‘bring order to the streets’ totalitarian like Pinochet, with free helicopter rides for Swampies? Joe the Georgain brought order, of a sort, once he stopped robbing banks and shopping his mates, so the swag was all his. Or that Austrian fellow, whose name I forget.
    Please God, let’s have the former, and soon.
    Perhaps Sir/Lord Nigel of Dundee would like the job?

  18. In fact if they built a decent Chunnel under the Bering Strait making max use of the islands you really could catch the train from London to NYC. Or the bus. At least it’s a better idea than HS2 or that daft Californian high speed railway line.

    A Transatlantic Tunnel, Hurrah! by the inimitable Harry Harrison.

  19. Tim the Coder,

    “Question is who? A freedom and sound economics ‘Mrs Thatcher Mk2’, or a ‘bring order to the streets’ totalitarian like Pinochet, with free helicopter rides for Swampies? Joe the Georgain brought order, of a sort, once he stopped robbing banks and shopping his mates, so the swag was all his. Or that Austrian fellow, whose name I forget.
    Please God, let’s have the former, and soon.
    Perhaps Sir/Lord Nigel of Dundee would like the job?”

    The Conservatives are a bunch of statists from almost the bottom to the top. The activists are overwhelmingly One Nation. The membership do not involve themselves much. There’s a handful of good ones like Truss, Philip Davies, John Redwood, Steve Baker. Not enough to take over and start purging the One Nation types.

    The best chance is probably the Reform Party. It’ll be interesting to see what happens in the next by-election. A lot of people on the right are pissed off with the Conservatives and might well switch.

  20. @BiS the newspaper comment bit is interesting enough, since almost all the news outlets have a Censorship Department Moderation Queue that precludes any comments containing views that are Against the Narrative “not compliant with established scientific views ( see our T&C )” from even appearing..

    The Elyan Sage is by far not the only one scrubbing his comment feed..

  21. “I’m not sure it’s oligarchs on cruise liners”: I was referring to their superyachts. I suppose cruise ships to be for retired dentists and burglars.

  22. “If you could shave a day off the old record, and have London to NY in a little over 2 days”. But not by sailing ship, which is the low-carbon way.

  23. OK… On the subject at hand…

    https://www.ammoniaenergy.org/wp-content/uploads/2020/08/Reaction-Engines-MailOnline.jpg gives the picture-that-says-etc.

    So they’re using a catalyst to partially turn the ammonia into H2 and N2, then burn the hydrogen, presumably using the rest of the ammonia to act as a catalyst against NOx.

    Curious how they’re going to do that without gettng , as one of Musk’s rocketeers stated: “an engine-rich exhaust”, given that hot ammonia is… rather agressive. Effectively nitrous/ic acid when it comes to the environment of the combustion chamber.. N. and O. radicals are… quite reactive, and love metals.

    And, as mentioned, the energy density is… mediocre.. to be polite. Even worse when you consider that all reactions to get rid of the inevitable NOx are endothermic, reducing the effective energy output even more.

    It may all be technically possible, but whether it is efficient and economically viable given other options… Doubt It.

  24. “Effectively nitrous/ic acid when it comes to the environment of the combustion chamber.. N. and O. radicals are… quite reactive, and love metals.”

    Aren’t a lot of the structural members of airliner wings actually inside the fuel tanks? The “wet wing” design? So they’d have to go over to separate tanks. Increasing mass & reducing fuel capacity. Or they’d have to be awfully sure of their coatings resisting cryogenics & the constant structural flexing/contraction/expansion. Those radicals will always present in any body of ammonia. High energy particles (particularly at altitude) break molecular bonds. How ozone forms from O2. Only in relatively small amounts but you don’t need a lot if the structure’s Al alloys.

  25. @BiS
    Exactly so. There’s a huge amount of stuff inside an aircraft fuel tank, although I think the deck chair is apocryphal.
    And yes, it’s direct against the wing & rib structural alloy (with the usual yellow-green anti-corrosion layer).
    And as I mentioned above, the fuel serves many other purposes than just fuelling the engines: circulating coolant, heat dump, FADEC hydraulics, CoG management.

    Perhaps the biggest challenge would be keeping the ammonia 100% anhydrous. From a massive tank on the airport, to a motor tanker, to a wing, then fly though rainclouds.
    With what will you fill the ullage?
    Or do we fill what’s left of the cabin with LN2 tanks (Halon being banned)?

    I suspect this story is just trough feeding. Oink Oink.

  26. Grikath: that pic looks a lot like some modern rocket engines that pre-react fuel & oxidiser. As you say, the product is reactive as hell. For a rocket it only needs to suffer for a few minutes whereas jet engines have lifetimes before significant maintenance in the thousands of hours range.

    As a subsidy farming wheeze it looks good, and the final report will probably say tests went well but they couldn’t crack the blade erosion issue.

  27. So this would exhaust water vapour into the upper atmosphere? Someone’s forgotten what the anthropogenic hypothesis actually says . . .

    Exactly! Any “alternative” system that puts extra water vapour into the atmosphere is pointless, because “extra water vapour into the atmosphere” is precisely the alleged problem* with carbon dioxide.

    *It’s totally the Underpants Gnome part of their argument. The most likely result of extra CO2 is more life in the oceans leading to future white cliffs being laid down.

  28. You’re not really discussing how much water airliners put into the atmosphere, are you? One of those little fluffy clouds you see passing overhead contains about a thousand tons.

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