Airbus eyes hydrogen power for airliner in next decade

https://www.ainonline.com/aviation-news/air-transport/2020-07-21/airbus-eyes-hydrogen-power-airliner-next-decade

by prostoalex • 6 years ago

118 141 6 years ago

Havoc3• 6 years ago

That would be good. I'd love to travel more without feeling guilty about the env impact

akkawwakka• 6 years ago

I feel more guilty about our usage of non-renewable, GHG-generating power sources like coal or natural gas power plants, and about driving around in my car (even though it’s electric).

Aviation accounts for just 2% of CO2 emissions. While it’s good that Airbus is considering alternative, greener fuels, because aviation will continue to grow, there are larger determinants of GHG emissions and warming.

Also, how you even certify use of hydrogen on an aircraft will be a challenge. The current design for fuel has been well-understood for seventy-five years now, and like the rest of aviation some improvements have unfortunately but unavoidably come from tragedy (see TWA 800). You can throw a match into Jet-A and it won’t catch fire. Throw a match into a flask of hydrogen and you have a fire or explosion.

coeneedell• 6 years ago

I've noticed that a lot of the discussion around environmentalism is focused as if the bad decision-making is happening at the consumer level. The pervasive belief that A: electric cars directly reduce your personal carbon footprint (they do, but the substantiality of that depends on where you live) and B: travel is a major drain on the environment are very suspicious to me. These are pervasive beliefs among environmentalists. Meanwhile very little attention is paid to corporate and nation level changes. The best thing you can do for the environment is vote. This feels counterproductive but it's entirely true.

In addition, it seems to me that the discussion around nation level changes has become focused on a developed nations vs developing nations issue, when in reality it's all of our issues.

lcam844• 6 years ago

Aviation is responsible for 2% of carbon emissions but was growing at 4% per year. Aviation is responsible for the mass tourism that drives people out of cities to make way for airbnb's. This increases their commute. It also increases real estate speculation, i.e. more construction of houses (cement alone accounts for another 2% of emissions). We cannot take a reductionist view of the problem. Mass tourism was one of the biggest environmental problems and was based on aviation. Travelling by air is a privilege that only a small percentage of the population has access to. If everyone did that we would quickly exhaust our carbon budget.

WalterBright5• 6 years ago

You can throw a match into Jet-A and it won’t catch fire.

Yeah, well, we all know jet fuel burns very well and that's why it's so useful. Fire is the worst crisis on an airliner.

Melting_Harps• 6 years ago

Aviation accounts for just 2% of CO2 emissions. While it’s good that Airbus is considering alternative, greener fuels, because aviation will continue to grow, there are larger determinants of GHG emissions and warming.

Agreed. This is why, despite being an active member in the sustainable movement for nearly 18 years now, I've never once felt 'ashamed' due to my travels all over the World and will continue to do so. The model shows that unsustainable living habits, particularly those of waste and uncaptured value due to loss in these network,s are the real glut of not just CO2 emissions, but also of CH4 and other more harmful GH gasses.

If anything Travel, not to be mistaken with tourism, can open your eyes to seeing your Fellow Human as you see yourself as you interact and briefly and live as he does and in turn walk away with a Global sense of Community and an understanding that cannot be conveyed in books, TV or movies. I think it's why despite my 'radical thinking' I sincerely feel that the ICE based model for airplanes, and rockets will likely always remain. We should strive for constant refinement, not scrapping it since it accounts for so little of total GH emissions and can have a high ROI.

These are pervasive beliefs among environmentalists. Meanwhile very little attention is paid to corporate and nation level changes.

No, its just not enforced up on by Nation States, as they often have strong incentives to keep things as they are, the environmentalists (I'm one) have been pushing for corporations to be held accountable for eco-cide [1], and be held accountable for all the costs it has and will incur, which in turn could help fund the remediation of those sites.

The best thing you can do for the environment is vote. This feels counterproductive but it's entirely true.

No, entirely false, for the reasons listed above. The best you can do is think Globally and act locally about the problem. That is begin to get active in these matters in your community and share your ideas and build a collective of people driven to see these goals get accomplished in real-time; the State will not do it for you, and waiting and relying on them to do so is how we got to this point and why its so wide spread. People are still surprised when they're expected to use their corrupt Legal system and expect another result?! Your diffusion of PERSONAL responsibility to this apparatus is the real problem, not what specious reasoning or beliefs some 'environmentalists' may or may not have or use.

Voting gives you the illusion you're doing something, when you really aren't and are only really validating a flawed concept with your continual participation, and the idea of it ever really making any difference is where you see the divide between people who actually do, and those that only talk about it. The former being where most people remain to this day on the matter(s) even as the problems continue to compound.

1: https://ecocidelaw.com/the-law/what-is-ecocide/

masklinn8• 6 years ago

The vast majority of the existing hydrogen pipeline is sourced from fossil fuels, so that's more of a greenwashing thing than actual environmental impact improvements.

Someone• 6 years ago

I don’t think that’s a strong argument against hydrogen. At the moment, the vast majority of everything we build uses fossil fuels, including most batteries. Most batteries are even charged using power from fossil fuels.

What matters is whether hydrogen tanks can be a cheaper or better approach to storing and transporting lots of energy than competing technologies.

Proponents of using hydrogen say existing electricity infrastructure has way too little capacity making hydrogen, which can be pumped through existing gas lines, an attractive approach alongside electricity for transporting power. That makes it more attractive for storage, too.

Havoc3• 6 years ago

For now. Once the hydrogen economy gains scale I would expect that to improve

cagenut• 6 years ago

Thank you for at least acknowledging it openly. A cultural shift is a necessary (though ofc not sufficient) part of this.

Havoc3• 6 years ago

It is sorta getting out there. Eg our corporate booking portal told you price and carbon emission so it was at least sorta in your face every time you fly

ncmncm3• 6 years ago

Hydrogen's energy-density makes it by far the best possible fuel for aviation. Improvements in aerogel manufacturing are making liquid-hydrogen tanks a practical prospect. LH2 is not mass-dense enough to fit in the wing tanks of existing airframes, but at least the LH2 tanks won't need to be pressure vessels.

Production of LH2 from cheap solar- and wind-generated electric power and water, right at the airport, will make aviation the most practical place to start using hydrogen as a fuel. Maybe auxiliary LOX tankage could help reach cruise altitude more quickly, or enable flying higher, so as not to waste the oxygen by-product.

MrBuddyCasino• 6 years ago

Hydrogen's energy-density makes it by far the best possible fuel for aviation.

gasoline: 45.8 MJ/kg hydrogen: 120 MJ/kg

What about safety? I visited the Zeppelin museum in Friedrichshafen last week...

Wouldn't it be nice if turning CO2 into gasoline would enable us to re-use tall the existing infrastructure?

pfortuny• 6 years ago

Zeppelins were essentially giant gaseous hydrogen balloons. That is directly flammable.

AFAIK liquid hydrogen tanks are orders of magnitude safer (as in “a totally different problem”).

ncmncm3• 6 years ago

The Hindenberg blew up because there was a bomb on board. No aircraft design is noted for resistance to onboard explosives.

Furthermore, the flames seen in the film were from kerosine fuel. All the hydrogen released went up, up, up. It is quite difficult to ignite hydrogen at atmospheric pressure; it requires oxygen mixed in a narrow range of partial pressures.

So, no, safety of H2 fuel is not a problem.

lcam844• 6 years ago

What is the best energy return of energy invested of hydrogen?

HPsquared• 6 years ago

Hydrogen only has a high energy density by weight, but by volume it's actually quite low compared to other liquid fuels. Then you have all the problems with handling liquid hydrogen, insulation needed, all sorts of additional functions are required of the storage system compared to jet fuel. For example, icing would probably be a problem if the wing tanks are full of liquid hydrogen!

dieortin• 6 years ago

Considering the freezing point of hydrogen is −259.14 °C, I doubt it would be a problem.

ncmncm3• 6 years ago

Considering that the post you replied to specifically noted that:

(a) H2 is energy-dense but not mass-dense,

(b) wing tanks are not a practical place to carry LH2,

it makes me wonder what you think this comment adds to the discussion.

stormdennis2• 6 years ago

Evokes the Hindenburg disaster for me though I presume that this would be no more of a fire risk than today's aircraft fuel.

layoutIfNeeded• 6 years ago

You can drop a match in jar of jet fuel and it will go out. Don’t try the same with hydrogen.

https://youtu.be/7nL10C7FSbE

WalterBright5• 6 years ago

There are many aviation disasters caused directly or indirectly by the fuel catching fire.

Such as the horrific SST crash.

The idea that jet fuel is somehow safe is just a terrible misjudgment of the situation. What we have learned over time is how to handle it safely - but it is NEVER safe and it DOES burn. Another way to set it merrily burning is to scrape an airliner along the runway, or have the airliner hit any sort of obstacle, or for the fuel to leak onto hot engine parts, and on and on.

stormdennis2• 6 years ago

Interesting video, not what I was expecting results wise.

protomyth• 6 years ago

Well, I presume Airbus will not paint the planes with something akin to rocket fuel.

regularfry3• 6 years ago

Neither did Luftschiffbau Zeppelin.

jeffreyrogers7• 6 years ago

At least an airplane can land without power, though the idea of a hydrogen aircraft (with the hydrogen stored in the wings if it's anything like conventional aircraft) catching on fire is pretty terrifying.

walrus014• 6 years ago

For reference from the UAV industry. The very best lithium ion batteries are about 250Wh/kg but limited in the instantaneous amperage they can put out. High amperage capable batteries are more like 170Wh/kg.

UAV compressed hydrogen tank systems with fuel cells in the 800-1600W range, the full system with tank, fuel cell and a small buffer battery works out to between 800-1200Wh/kg depending on size. Some guys in south Korea recently hovered a large hexacopter for 10.5 hours. The systems I've seen are typically configured for an output voltage equivalent to the float voltage of a 12S lipo.

Diesel fuel, jet a, avgas and other fuels are a whole magnitude more dense in Wh/kg stored than the above-mentioned hydrogen system.

dthakur• 6 years ago

Could you kindly provide a link for the hovering hexacopter please? Thanks.

culturestate• 6 years ago

I assume they're referring to https://www.youtube.com/watch?v=_U_dHZZ3vxQ&feature=emb_titl...

Retric2• 6 years ago

Hydrogen becomes significantly more efficient as you scale the tank. Don’t forget many rockets use Hydrogen over Jet-A and they really care about weight.

mhandley• 6 years ago

Rockets use liquid hydrogen, which is a pain to work with, but not too bad if you can fuel up and launch relatively quickly before too much boils off. The real reason rockets use hydrogen is because Hydrogen and Oxygen gives the highest specific impulse of any chemical rocket. You really don't care about specific impulse in a jet aircraft, and you really don't want the fuel boiling off before the end of your 12-hour flight.

Also, if you're thinking of pressurized gaseous hydrogen instead of liquid hydrogen, then the tanks get really heavy because high pressure tanks don't scale well (unlike low pressure liquid tanks which do). Hoop stress is proportional to diameter, which means tank wall thickness needs to grow with diameter too. https://www.engineersedge.com/material_science/hoop-stress.h...

sandworm101• 6 years ago

Some rockets, and generally on lower-thrust high efficiency upper stages. Hydrogen has a low energy density in terms of volume. It requires larger tanks and so is rarely used to get off the pad.

paledot2• 6 years ago

RP1 is effectively a purer version of Jet-A, and is a very common propellant. I'd say it's more popular than hydrogen, but I'm not sure I can back that statement up. It's what fuels the Falcon 9 lower and upper stages.

5ersi• 6 years ago

Actually liquid H2 has energy density of 39 kWh/kg, where common CH fuels are around 12-13 kWh/kg. So about 3x more energy per kg then conventional fuels.

jcranmer• 6 years ago

Note that H₂ boils around 20-30K (depending on pressure). Once you take into account the weight of the insulated tanks, liquid H₂ is going to have much worse energy density.

cheerlessbog• 6 years ago

That's without the weight of the storage and potentially fuel cell surely.

formerly_proven• 6 years ago

Yes, but that's without the container, which is very heavy for the hydrogen, while a plastic bag is already good enough for fossil fuels.

elmo2you5• 6 years ago

Aside from the (obvious) energy density downside of hydrogen as a fuel, there is another substantial problem.

Hydrogen is challenging/expensive to store/contain. Kind of the direct result of it being the smallest atom we have. Even more important: when it reacts uncontrolled, in particular with oxygen, it does so at a truly frightening speed. Once it goes, good luck doing anything about it.

The fact that this is almost never mentioned in every yet-another-hydrogen-is-going-to-be-our-future-next-year piece, always makes me wonder if that's the result of not-so-honest entrepreneurs trying to lure investors, or that none of these jokers ever talked to any experienced chemist.

This is no attempt to spread FUD regarding hydrogen. It sincerely worries (if not frightens) me, how so many initiatives appear to completely ignore that any volume of hydrogen that is sufficient to power something that can transport humans or cargo, is pretty much inherently a catastrophic disaster in the making. That is, if such a system would ever fail in a way that makes the stored hydrogen react uncontrolled.

Every widely utilized technology is bound to fails, even if only in edge cases, and of course: extra safety margins/features can be added to limit the effects of failures. But with hydrogen that might be a hell of a lot more expensive and/or difficult than most would realize.

So, the way I see this is that we either end up very cost ineffective solutions, or ones that will be far more dangerous than many would ever realize. That is, until something goes terribly wrong, and everyone realizes they have been ignorant and maybe even intentionally fooled by people trying to make money. Reminds me a bit of self-driving cars.

jeffreyrogers7• 6 years ago

If your fuel tank catches on fire you have similar problems, so I don't think these problems with hydrogen are insurmountable.

jonsen3• 6 years ago

It seems like you are not aware of existing production of hydrogen cars:

https://en.m.wikipedia.org/wiki/Toyota_Mirai

dehrmann2• 6 years ago

If you had a hydrogen tank in a plane, would you be better off using it as a fuel in a jet engine or using it to power motors with a fuel cell?

jonsen3• 6 years ago

“Hydrogen needs a bit more work” for use in gas turbines, but it is something Rolls-Royce is examining, along with electric.

benhurmarcel• 6 years ago

Both are being researched. The answer to that isn’t clear-cut.

simonebrunozzi• 6 years ago

What about liquid hydrogen, which is much denser than compressed one? Not an option for UAV?

rstuart4133• 6 years ago

UAV compressed hydrogen tank systems with fuel cells in the 800-1600W range

They didn't say how they would be using the hydrogen. I haven't been able to find it again, I did read about an article about a long endurance (days), high flying plane. It was powered by hydrogen. It burnt it. As I recall it was in an ICE, but at 50% efficiency using it as jet engine fuel isn't such a bad idea. It has an energy density of 120 MJ/kg, 3 times as much as normal fuels so it makes sense either way, if you can contain it.

In other news, the country where I live (Australia, 6th largest exporter in 2019) is contemplating exporting hydrogen. Why? Because if renewable power continues on its current price trend it will be cheaper to produce hydrogen than it is to mine the natural gas we currently export. Again, I presume no fancy technology - it will be burnt just like the natural gas is.

Kuinox3• 6 years ago

In my city there is a bus using a hydrogen fuel cell. I noticed it produced interference in my bluetooth headset with noise reduction (I can hear the engine in my headset), i'm curious if it will interfer with plane sensors.

_fizz_buzz_• 6 years ago

This is maybe an inverter. But definitely not the fuel cell itself. The fuel cell will produce pure DC current which won't interfere with anything. However, e.g. a DC/DC inverter that steps up the voltage might not be well shielded.

Gwypaas• 6 years ago

I always wonder if hydrogen is a side-step without any real practical use or will somehow create a niche where the high-density requirements of long range travel are needed. I.e. airplanes and cargo ships.

Hydrogen is awful to store and has no existing infrastructure around it, and you only get efficiency gains if you use fuel cells, otherwise it's back to Carnot's law.

Compare this to synthetic biofuels. They are already the market, as an example I can go fill up my diesel car right now with it, certified to work by the manufacturer, and can be transported and used by existing infrastructure.

Why isn't this talked about more? Are the land usage requirements making it unfeasible for a global switchover in the aviation and maritime industries requiring converting CO2 from the air making it much more expensive? Or is it simply not flashy enough?

m4rtink• 6 years ago

I'm not sure hydrogen can be really said to be high density - at least as rocket popelant it is notoriously low density, even in liquid form.

WJW• 6 years ago

Compared to battery packs (the main competitor for "green" vehicles) it has a very high energy density.

pa7x1• 6 years ago

There is two densities to care about when talking about energy sources. Energy density per volume unit and energy density per mass unit.

Hydrogen has a very high energy density per mass unit (the highest of the chemical reaction energy sources). But lower energy density per volume than Li.

The two figures matter for different use cases, cargo-ships and aviation want to optimize for energy density per mass, while small passenger transport (e.g. scooters, cars...) wants to optimize for energy density per volume.

Energy density per mass graph: https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...

baybal22• 6 years ago

If you have tons of near free energy, and hydrogen, making other synthetic fuels, which are way more storable is not a problem, a ton of other avenues will open in chemical industry for "direct synthesis"

Fuel cells can also use synthetic fuels, including hydrocarbons, and ammonia.

masklinn8• 6 years ago

Hydrogen is awful to store and has no existing infrastructure around it, and you only get efficiency gains if you use fuel cells, otherwise it's back to Carnot's law.

Plus the hydrogen production pipeline is mostly from hydrocarbon so it's no gain at all. AFAIK hydrolysis is currently rather expensive and mostly for situations where you need very pure hydrogen (e.g. scientific application).

regularfry3• 6 years ago

Part of the discussion in the UK at the moment is around the feasibility of reusing existing natural gas infrastructure (good luck with that) and building explicitly green hydrogen plants as opposed to generating from hydrocarbons.

The problem is the scale you'd need to make a dent. It's being proposed as a serious solution to road and rail transport hydrocarbon use, and the power requirements are bigger than anyone I've seen addressing. The last-mile distribution problem is also not inconsiderable, but it pales in comparison to having to copy and paste a chunk of our existing renewable energy fleet.

baybal22• 6 years ago

energy can be carried onboard through fuel cells to drive gas turbines

I don't think the author has a slimmest idea how gas turbines, and fuel cells work

jacquesm7• 6 years ago

There is no way you'd get me on a hydrogen powered aircraft. Hydrogen is a tricky substance to handle at the best of times, it explodes with the least provocation and has a lot of effect on the materials that package it. By then I hope my flying days are over but just in case they aren't that is something that would have an immediate impact on my decision to travel or not.

darkerside2• 6 years ago

I assume this is fear of a Hindenburg type incident? I would assume that these aircraft would be carrying much less hydrogen, since it's used only for propulsion, not as a lighter than air filling. But, that's only speculation. Anybody have facts to inform this?

jacquesm7• 6 years ago

Here is an example:

https://electrek.co/2019/06/11/hydrogen-station-explodes-toy...

Hydrogen needs to be treated with the proper respect at all times when it isn't safely bound to something else. It really doesn't take much to set it off. That the Hindenburg ever got off the ground is what is impressive about it, the amount of care that went into ensuring that a static charge could never reach the reservoir must have been massive.

Hydrogen plants have exploded in the past as well. Given aircrafts' tendency to build up static charges and to be hit by lightning I would not bet on that particular technology to work out.

The Hindenburg was - and that a pretty weird thing to write - about as good as it gets for an accident like that. Only about 1/3rd of the people on board died and it happened during a time when the aircraft was already fairly low (during the last stage of mooring). Had this happened at altitude likely all hands would have been lost.

korantu2• 6 years ago

If my understanding is correct, the goal is to reduce aviation effect on climate change.

There is an ongoing project [1] by US NAVY to turn seawater into jet fuel. This way we would not need to burn fossil fuels and would not need to throw away much of existing aviation technology.

[1] https://www.eurekalert.org/pub_releases/2020-07/uor-lch07152...

gus_massa• 6 years ago

Note that this convert

H2O, CO2, energy -> fuel

Water is free [1], Carbon Dioxide is free [2]. Energy is never free.

You need some big solar panels or a nuclear reactor to get the energy. (Can you put a wind turbine in a ship?) (The usual trick of burning fuel to produce energy is not a good idea here.) So this kind of process should not be interpreted as "water -> fuel" but like "energy -> fuel".

It can be useful to store energy for a while, or producing fuel using a nuclear reactor in the carrier and using the fuel in the planes. (I'm not sure that this is economical or tactically a good idea.)

If the idea is to produce the fuel on land, it is much more efficient to sell the energy and buy fuel. The energy you sell will cause a electric plant that use carbon to close and the net effect will be bigger reduction of the CO2 level.

From the article:

Laboratory team led by Heather Willauer announced it had used a catalytic converter to extract carbon dioxide and hydrogen from seawater and then converted the gases into liquid hydrocarbons at a 92 percent efficiency rate.

I really doubt this. Organic reactions have a horrible low efficiency, specially the ones that create complex molecules using simple ones. (Perhaps the 92% efficiency is counting how many of the CO2 are converted, but the most important part of this reaction is the energy. If it convert the 92% of the CO2, but it stores only the 1% of the energy, it is very wasteful.)

[1] Processing water to avoid the problems with salt and tartar may be a big problem, so it may not be so easy.

[2] But the concentration is usually low, that is generally bad for fast and efficient reactions.

guerrilla• 6 years ago

Thanks for the details.

On the other hand, doesn't this incentivize carbon capture by making the cost of energy storage just energy?

jjoonathan• 6 years ago

In terms of energy, it's not a contest and it's not a hangup. Carriers are already powered by nuclear reactors. They have about 1500MW of steam power available as a matter of course. Compare to 25MW if you paved the flight surfaces with solar panels and parked it at the equator on a sunny day with perfectly calm seas and measured at noon. Unlike solar in this example, the nuclear design is not bumping up against physical constraints and could be scaled up quite dramatically if there was a compelling reason to do so. Fuel production would be a compelling reason.

The chemistry and chemical engineering problems you point out are the major hangups.

vikramkr• 6 years ago

Sayong they are converting water to fuel focuses on the wrong (least important) part of it. The point is that it fixes CO2 from the air into hydrocarbon fuels via generating carbon monoxide and using the Fisher troph process to assemble fuel molecules. This is really just congealing electrical energy into hydrocarbon fuel. For now in the lab, you still get that energy from fossil fuels. Presumably in the future you would use this process to congeal extra solar or wind energy into fuel rather than keep them stored in batteries

korantu2• 6 years ago

In this particular case, they are planning to take energy from carrier's nuclear power plant.

More generally, either hydrogen or fuel synthesis requires energy to come from somewhere; In this regard it is no different than re-building airplanes to use hydrogen, as the original article suggests.

The point is that we might have better chances synthesising fuels usable in existing planes, versus re-building majority of aviation to use hydrogen.

holoduke• 6 years ago

just curious, but what about nuclear powered planes. didn't the us and Russia had operational planes back in the 70s?

jeffreyrogers7• 6 years ago

I know there were some test engines, but none every flew to my knowledge. The problem is they spit out radioactive matter over everything they fly over and expose the occupants to a lot of radiation (since you can only contain the radiation so much when you have weight limits to make). They are badass though.

aunty_helen2• 6 years ago

When you demand power from the reactors they make a lot more radiation. There wasn't a way to shield the crew without a lot of lead plating.

Lots of weight in an aircraft was the deal breaker. I think the ruskies did end up with something flying but I'm not confident about that.

alkonaut• 6 years ago

Hydrogen is expensive to produce, cumbersome and dangerous to store and handle. How will that be competitive with traditional jet fuel?

Jet fuel is safe to handle, the infrastructure is there, it doesn’t go all Hindenburg in a crash, and it doesn’t require new engines.

What we need in the next decade is a better jet fuel.

If commercial flights all used 50/50 renewable fuel that would cut greenhouse emissions in half. Providing that much biofuel without disrupting food production or fresh water supply will require a moonshot effort but it still seems like a simple obstacle compared to replacing fleets with electric or hydrogen powered aircraft.

Thlom• 6 years ago

People need to fly less.

iso1210• 6 years ago

If commercial flights all used 50/50 renewable fuel that would cut greenhouse emissions in half.

Airline emissions aren't that bad compared with everything else, but they aren't being decarbonised at the same rate like everything else, and on top of that they are growing dramatically.

In 2019 there were 4.5b passengers globally. In 2006 there were 2.25 passengers globally, so doubled in 13 years. Planes are slightly more efficient now, but there's a long tail of less efficient planes.

Moving to 50:50 biofuel may save a decade of growth, but it's not a silver bullet.

jacquesm7• 6 years ago

Also, Hydrogen isn't a fuel, it is a storage medium, a battery if you will.

masklinn8• 6 years ago

That could eventually be true, but currently under 5% of hydrogen is produced by electrolysis or biomass gasification, the rest is all processing of fossil fuels.

dehrmann2• 6 years ago

We could also ramp up nuclear power production and build hyrdocarbons from water and CO2. Lots of things become more practical with cheap, abundant power (assuming we can get that from nuclear).

socialdemocrat• 6 years ago

Stupid choice. Combine electrolyzed hydrogen with CO2 Instead to produce methane. A safer and easier fuel to handle and use. SpaceX is already developing their rockets to use it.

Hydrogen is too much of a trouble fuel with no infrastructure in place to handle.

The problem is of course where to get the CO2 from. It should be gotten from some kind of carbon capture setup. Ideally from biomass power plants.

otterley2• 6 years ago

Methane is a greenhouse gas[1] - much more potent than CO2, in fact. The objective is to be environmentally friendly as well as economical and safe.

[1] https://www.edf.org/climate/methane-other-important-greenhou...

Ericson2314• 6 years ago

As long as your fuel tank doesn't like it's fine. Burnt methane is back to CO2.

What this whole thread boils down to is we need a huge amount of nuclear power, after which rather than worrying about all 3 of "safe", "dense", "efficient", we can just worry about the first 2.

Seriously, if it takes 1000x the energy from nuclear power to fix enough C02 to make conventional jet fuel from the air, that is fine. That's something we can optimize on a leisurely basis when we are not worrying about global warming.

fnord77• 6 years ago

in general, biofuels are not the greatest, but it might be the best solution for aviation.

The US military has already proven a jet aircraft can be run on biofuels.

otterley2• 6 years ago

Combustion of biofuels still produces CO2, which is one of the outputs these projects are trying to eliminate.

aunty_helen2• 6 years ago

The concept of biofuels is a closed carbon cycle (more closed but not ideal). Plants with the aid of the sun scrub CO2 from the atmosphere, you make the plants into biofuel and then burn that back into CO2 in the atmosphere.

As opposed to digging it out of the ground where it's happy staying outside of our environmental system.

LargoLasskhyfv• 6 years ago

[1] https://duckduckgo.com/?t=ffsb&q=slush+hydrogen

Simulacra• 6 years ago

Ok..but.. what about kaboom?

dfilppi• 6 years ago

Oh the humanity

kemiller• 6 years ago

It really seems like synthetic fuels using water and co2 and excess solar energy as inputs Is probably the best bet ultimately.

jacknews• 6 years ago

butanol was being highlighted a few years ago. I don't know it's still a good choice, or some problems were discovered.

joyj2nd• 6 years ago

Old news. Germans did this before. https://www.history.com/.image/c_limit%2Ccs_srgb%2Cq_auto:go...

credit_guy2• 6 years ago

This is nonsense. If they want to be net zero emissions, they can use synthetic jet fuel produced from sea water. The US Navy has studied the topic and concluded they can produce such fuel at a cost of $3-6 per gallon [1].

[1]https://www.zmescience.com/research/us-navy-synthetic-jet-fu...

Hypx2• 6 years ago

Synfuels are made using H2 and CO2. In practice, they're just H2 with more steps. So while you can use them, it ends up being a trade-off between cost and how much you really need synfuels.

credit_guy2• 6 years ago

Yes, but synfuels are a drop in replacement of the current fuels, and they are net zero emissions. Hydrogen is nasty. Really, really nasty: in liquid form it can only be stored at impossibly low temperatures, it has a very low density (about 13 times less dense than water), it leaks easily, it creates frost (remember the o-rings from the doomed space shuttle). Building a new airplane is difficult enough, building that burns hydrogen instead of regular jet fuel is an enormous engineering challenge. The chance of us ever seeing a hydrogen-based airplane is exactly zero.

Airbus eyes hydrogen power for airliner in next decade

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