Scientists Turn CO2 Into Jet Fuel (wired.com) 144
Researchers may have found a way to reduce the environmental impact of air travel in situations when electric aircraft and alternative fuels aren't practical. Wired reports that Oxford University scientists have successfully turned CO2 into jet fuel, raising the possibility of conventionally-powered aircraft with net zero emissions. From a report: The technique effectively reverses the process of burning fuel by relying on the organic combustion method. The team heated a mix of citric acid, hydrogen and an iron-manganese-potassium catalyst to turn CO2 into a liquid fuel capable of powering jet aircraft. The approach is inexpensive, uncomplicated and uses commonplace materials. It's cheaper than processes used to turn hydrogen and water into fuel. There are numerous challenges to bringing this to aircraft. The lab method only produced a few grams of fuel -- you'd clearly need much more to support even a single flight, let alone an entire fleet. You'd need much more widespread use of carbon capture. And if you want effectively zero emissions, the capture and conversion systems would have to run on clean energy.
So what's the efficiency? (Score:2)
There are no big challenges except for making it usefully efficient? So how efficient is it now, and how efficient does he think he can make it? These all-importan
Re: (Score:2)
How does it scale. That's more important than efficiency. These technological solutions look like little more than bookkeeping tricks to me, but they sure attract money.
Re: (Score:3)
Re: (Score:2)
They don't know if it will scale. Still, no matter what it is going to take more energy to un-burn carbon then they could get back, so there really isn't much point.
Re: (Score:2)
I know it won't scale. machines to extract CO2 from the air are useless. Plants may not be efficient but these you can scale - Of course there is still a major difference between really putting it back in the ground and of piling tons of oil-derived fertilizer on it after which you just burn it up again.
"Efficiency" is a red herring (Score:2)
What does it matter, when it's solar-powered? Do it right next to the solar power tower. We're not gonna run out of sun, anytime soon. And if we do, we will have bigger problems.
It certainly will be more efficient than plants, by the way.
Re: (Score:2)
Re: (Score:2)
You are right. Our modern form of solar power is technically more efficient than the chlorophyl => photosynthesis model currently used by plants.
Depends on how you define "efficient", We can generate electricity very efficiently, but how do you compare that with plants? Plants don't generate electricity at all.
Plants do photo synthesis , so the comparison would be, how well does our form of solar power compare in efficiency to synthesizing sugar from carbon dioxide, water, and sunlight? The answer there is, terrible. Plants are much better.
Re: (Score:2)
And our oil comes from ancient plants.
So how effecient is the solar > plant > oil compared to solar > electricity > oil
Re: (Score:2)
Most anti GMO people are very scientific.
Just saying.
Re: "Efficiency" is a red herring (Score:2)
Is that true? I'm sort of anti GMO (with qualifications, which I will not go into without a keyboard) so I want to believe you, but I've talked to too many anti-GMO idiots who don't know Jack about shit.
Re:"Efficiency" is a red herring (Score:4, Interesting)
While we won't run out of sun, we don't have limitless solar energy capacity, nor can we wait an infinite amount of time to gather sufficient energy to do this process.
On an extremely favorable day (clear sky, temperature not needing heating or AC by and large, midday), excluding vehicle energy, South Australia managed 1 whole hour on solar power. This is great and all, but the fact that it is newsworthy in spite of the caveats, exclusions, and the very limited circumstances shows that we don't exactly have free energy to skip worrying about efficiency yet. We haven't proven that it is feasible to have enough solar collection and storage to drive all our energy needs, despite the promising fact that so much energy is theoretically there for the harnessing.
This is an avenue worth being in the race, but it's hard to say that this would be practical before, say, breakthrough energy density in batteries that suddenly make jet fuel and battery technology equivalent.
Re: (Score:2)
While we won't run out of sun, we don't have limitless solar energy capacity, nor can we wait an infinite amount of time to gather sufficient energy to do this process.
Also, the people that most want us on solar power will also most want us to use as little space, and as little of an environmental impact, as technologically possible.
This idea that efficiency doesnt really matter once you go solar is comical, and is clearly not being offered up by a true environmentalist, yet the person saying it clearly wants us to believe that they are in fact someone of significant climate virtue. There are the zealots, and then there are the posers. Fake. Phony.
Re: (Score:2)
It matters even if solar power because you need to decide whether your solar power is best fed directly into the grid or into some fuel making process. Efficiency always matters. Something about survival of the fittest.
Re: (Score:2)
Look at it this way - you burn carbon to get energy, which produces CO2. You reclaim as much CO2 as possible, stick it in a converter and pump energy in so that you get something out that you can burn again, but the end product of the converter is fuel that contains less chemical energy than you pumped into the converter. So, why bother? Why waste your solar power unburning carbon so you can burn it again at
Re: (Score:2)
Solar is expensive, intermittent, and takes up sunny area that could be used to grow food.
No, it does not.
The only "fields" covered by solar plants are fields that to be reconverted to more or less natural state due to EU rules for cutting down on how much food we make. And those plants are usually directly at a railroad where they can feed in. (And the fields close to rail roads are about to be closed anyway.).
No one is using a real food are to put up a solar plant. If you believe that: you re dumb.
We can
Any engineer/chemist here? (Score:2)
Regarding cars: How much of the energy generated from gasoline with good fuel cells would have to be used, to compress all the resulting CO2 from a full tank in another tank of the same size as the gasoine tank? Can it be condensed as quickl as it is made? And how easily can the also resulting water be separated, or would it have to go in the CO2 tank too?
Re:Any engineer/chemist here? (Score:4, Informative)
In terms of mass, CO2 portion of the exhaust has about 3x the mass of the gasoline combusted, so it would not be viable even if you could ditch the H2O.
The combusted hydrocarbons lose a bit of their mass in hydrogen, but most of the mass is in carbon (atomic weight 12). Each carbon picks up two oxygen (each atomic weight 16) from the atmosphere, and oxygen atoms are a bit more massive than carbon atoms, such that *roughly* they make up the difference of expelling the hydrogen if you could (technically, more than make up, but 3x is a nice round factor and good enough for a rough discussion).
Re: (Score:2)
Then call it 4x and you are basically at the correct value :P ... plus 2 extra H's at the ends of the chain, which take another O.
Because for every C you have 2Hs and another O
Re: (Score:2)
Right, 4X if you have to store the water (which practically speaking you would, but the question broached 'what if we could eject only the water', which even theoretically wouldn't be great).
Which is a fun thing to note, that a vehicle exhausts roughly as much water as gasoline was put in.
Re: (Score:2)
To quantify, usable energy density per mass is about 10x in favor of gas/avgas/diesel versus the best rechargeable batteries today (after taking into consideration the differing efficiencies).
A fun table can be seen at:
https://en.wikipedia.org/wiki/... [wikipedia.org]
Particularly the leap between the non-nuclear and nuclear energy sources is quite dramatic. A hypothetical nuclear battery cellphone would never ever need to be plugged in.
The only problem is... (Score:2)
"science reporting" (Score:4, Insightful)
It does get tiring when you read one more article where the author takes one very isolated accomplishment (creating a few *grams* of fuel) and extrapolates that to an article about how this new breakthrough converts undesirable matter (CO2) and creates jet fuel to power our fleets.
I applaud all basic research - there is so much more we need to know about the world around us. Reporting on what's going on in research labs around the world is a service to the public. But...
This sort of lazy journalism (sensationalizing a small, beginning step) is part of what gives "The Media" a bad name. We are nowhere near being on the verge of a new way to use all that pesky CO2 and converting it to fuel, so that people can fly guilt-free. Stay closer to the facts.
Re: (Score:2)
That is not lazy. It is market driven.
Re: (Score:2)
So can we therefor conclude markets are lazy?
Re: (Score:2)
Markets hollow out value through efficiency but I was thinking that comes only afterwards. The main thing is the product being 'interest'. They're not selling truth, they're selling interesting bits of information.
Re: (Score:2)
Re: (Score:2)
It does get tiring when you read one more article where the author takes one very isolated accomplishment (creating a few *grams* of fuel) and extrapolates that to an article about how this new breakthrough converts undesirable matter (CO2) and creates jet fuel to power our fleets.
Yeah I forgot. We all one day woke up next to a network of Standard Oil refineries and petrol stations and thought hmmm we could power cars with this. There's never a case where someone demonstrates something like catalytic cracking in a lab for a few grams and then within 7 years we had built massive thermal cracking units on the side of refineries. There's no way any of this started up with someone heating oil on a bunsen burner, it was always 20kbbl/day pipestills. /sarcasm
If it sounds like I'm mocking y
Re: (Score:2)
Gasoline is a waste product of oil refining. In that scenario, its "hey maybe we can sell this stuff we are already producing."
But this future energy thing you are talking about is not something already being produced, and while stuff like CO2 is produced in many many ways across many many industries, what you need to show is that of all the ways to turn this CO2 into a product, that this future energy one is going to be the most profitable among them, as otherwise peopl
Re: (Score:2)
Nope, Gasoline is one of the reasons we refine oil, not only is it not a waste product, but a good 2/3rds of a refinery is designed specifically to convert waste products into more gasoline blending components.
I'm amazed that you got as far as realising that refineries produce multiple things but then proceeded to throw away that thought in "future energy thing you are talking about is not something already being produced". You see your proposed mythical future gasoline would truly be a waste product. Now w
Good initiative considering jet fuel amount used (Score:2)
Posting primarily to undo moderation but though solar planes would be nice, it could help reduce environmental impact
Why call it jet fuel? (Score:2)
Why call it jet fuel?
Because piston engine fuel is a lot more demanding. Lower self ignition temperature, drop let combustion and leaner air/fuel mixture is needed for die
Re:Why call it jet fuel? (Score:5, Informative)
Good thing algae can be used instead (Score:2)
apropos your user name: https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:Why call it jet fuel? (Score:4, Interesting)
Because piston engine fuel is a lot more demanding.
Right. Piston engines are an odd niche technology; they aren't optimized for efficiency; they are optimized for being reasonably efficient, while producing high torque over a range of RPM in a package with good power/weight.
If we were inventing cars from scratch today, we wouldn't invent the weirdly complicated Otto cycle engine and the complicated transmisaions and clutches that are needed to make it propel a vehicle. We'd invent a high efficiency constant-power engine, buffer the output into a battery, and use high-torque electric motors for starting.
...Also with the advent of batteries on a 7 year Moore's Law, most piston engines will be gone in 10 years, the time it would take to bring this chemistry to market. Looks like that is why this team is drumming it up as jet fuel to get investments.
Interesting speculation.
Re: (Score:2)
That's pretty much what Honda does now in their hybrids.
They use an Atikinson-style cycle engine that's got a pretty crappy power band in their hybrids, but the efficiency is very good.
The only difference is that it has a lockup clutch to the single speed gearset for the gasoline engine to directly power the car at highway speeds, shortening the
engine -> generator -> motor -> gearset -> wheels
to
engine -> gearset -> wheels
for highway driving in the efficient powerband. The electric motor ca
Re: (Score:3)
Conventional gasoline and diesel engines are actually very simple and efficient compared to all alternatives and they deliver good power to weight ratio. There is a good reason why we don't use Stirling (it is "Stirling" not "Sterling"!) engines for everything. Turbine engines work efficiently for a narrow range of loads - which is fine for aircraft, but not fine for cars or even ships, as we see a return from gas turbine (do not confuse with steam turbine) powered warships to diesel power, at least for sma
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
The engine is "technically" a Diesel. But the fuel is not. Because of the cheap fuel, commercial ships usually have no gas turbines, that is all.
Re: (Score:2)
Which is exactly what diesel-electric locomotives have been doing for decades. Run the diesel generator at a constant RPM that efficiently produces the electrical voltage and amperage you need, buffer it, and drive electric motors with it.
Re: (Score:2)
Re: (Score:2)
I believe that this is what the Mitsubishi PHEV does when the gasoline engine is running. It's basically just a generator to either recharge the batteries, provide the power needed for freeway driving, or both.
Re: (Score:2)
Lotus actually designed a three cylinder engine with the generator integrated into the engine block, [greencarreports.com] .... back in 2010!!! A decade ago.
The 15 kW is exactly the power used by a Tesla model 3 in cruise. Design a car with about 15 kWh
Re: (Score:2)
> Because piston engine fuel is a lot more demanding.
Aviation fuel is a lot more demanding that automotive fuel. The tolerances on the chemical and physical properties are much tighter, and the overall purity is higher.
Aircraft engines need to be ultra-reliable and consistent, and they require high performance fuel for that purpose.
=Smidge=
Re: (Score:2)
But designing a new gas turbine to use a new fuel is easier than getting a piston engine to consume a new fuel. Piston engine combustion is intermittent, needs to start and stop, need finish at exacting time frames. Gas turbine burns the fuel continuously. So it would be easier for a new liquid fuel to target gas turbines than piston engines.
Re: (Score:2)
There is more than that. The sulphur in the fuel is used for lubrication.
Bull (Score:2)
It's like my rule on articles touting the wonders of resveratrol. Note the authors names and never read anything from them again. Life is too short.
Cow farts (Score:3)
Cow burps (Score:4, Informative)
This seems sketchy, and I doubt it would be economically feasible. We'd be better off adding seaweed to cow feed to reduce methane emissions. https://www.wired.co.uk/articl... [wired.co.uk]
Well, they're not mutually exclusive. We could do both.
Re: (Score:2)
How getting cows to stop farting work to reduce an industry that contributes 7% of our global emissions? Or are you under the impressions that we can solve climate change by doing just one thing? If that's the case .... hahahahahahahahahaha.
Did anyone doubt this is scientifically possible? (Score:2)
After all, biofuels do exactly the same thing: convert ambient CO2 to a fossil fuel substitute. The hard part of making this particular process work is going to be economic. CO2, despite its enormous environmental impact, is a trace gas, and recovering it from the atmosphere is going to be very expensive. You'd have to focus on emission *sources*, and big ones at that, like coal power plants, and those are barely economically viable even without adding more bells and whistles.
This may be like plastic rec
Re: (Score:2)
I can't see how this would be economical given how much energy is going to be lost in trying to unburn something so you can burn it again. Plus,
Useful for aircraft carriers (Score:2)
The Navy has been investigating this as a way to make aircraft carriers produce jet fuel from their nuclear generator. During wartime this might extend the duration that the carrier can defend itself. Adding energy weapons would also help too.
So the energy comes from... (Score:2)
I guess the energy comes from the hydrogen and the heating then? Kinda important to mention the conversion ratio then. How much J of energy do i need to put in to store 1 J of energy in this new magic jet fuel...
good research, poor reporting (Score:5, Informative)
This is an open access paper, you can read it here:
https://www.nature.com/article... [nature.com]
The core process they're using to convert CO2 into fuel is just about 100 years old. What they've done is develop a better catalyst for that process (a "traditional" Iron-Manganese-Potassium catalyst, but synthesized a new way). That is important!
There's a big error in the summary here: this process combines CO2 and hydrogen. This IS turning hydrogen into fuel.
This process is what the government people meant by "clean coal" 20 years ago. I'm a scientist, I wrote proposals back then to work on this exact process for "clean coal" programs. The core idea came from Nate Lewis, a chemist at Caltech who was the driving scientist behind "An Inconvenient Truth." In some alternate universe, when scientists and politicians made a push to fund and scale this technology in 2001, they would not have called it "clean coal" but some marketing term more palatable to environmentalists. In that case, we may have weaned ourselves off of fossil fuels by now. It's a shame we, as a species, have not worked harder on this.
Well, here's hoping we do better in the next 20 years!
You're not a scientist (Score:2, Troll)
And it will still introduce as much emissions of fossil fuels into the atmosphere as simply burning coal.
Re: (Score:2)
Re: (Score:2)
Thanks for the link to the article, that has some actual chemistry in it. I hasten to add that I am not a qualified chemist, but I have had occasion to study some chemistry as part of electronic and mechanical engineering work.
There is some similarity to the well-known Fischer-Tropsch synthesis of long chain hydrocarbons from carbon monoxide and hydrogen. I am not sure of the overall efficiency, including hydrogen production, and energy input for synthesis, followed by combustion of the synthesized hydrocar
Re: (Score:2)
Re: (Score:2)
Old news, US Navy did this long ago (Score:2)
This looks familiar...
https://www.washingtontimes.co... [washingtontimes.com]
While that article is six years old there's even older ones if I were to take the time to look. The US Navy has been begging Congress for funds to develop this technology. Maybe they'd get more funding if the Navy claimed they would run it from solar power instead of nuclear power.
It's the same process that the US Navy has been looking at for a very long time. Anyone trying it in the last decade either got the idea from the Navy or is working with th
Question about the hydrogen (Score:2)
Re: (Score:2)
Hydrogen is not a good fuel in many ways. Its energy density, compared to hydrocarbons, is very poor. Hydrogen gas needs to be stored under immense pressure to get a usable energy density. Hydrogen storage vessels tend to leak badly, as the tiny gas molecules get through pores in the walls.
If you can turn hydrogen into a more easily stored fuel, then it has potential for use in combustion engines. Making hydrocarbons using waste CO2 is a way of doing this, and could be carbon-neutral.
Re: (Score:2)
Hydrogen storage vessels tend to leak badly
They leak. But definitely not badly. That is a myth.
And in a situation where you are going to burn all the hydrogen anyway, as e.g. on a ship or in a plane: the little leakage does not matter at all.
Re: (Score:2)
Presuming that hydrogen leakage causing fuel loss is not a major practical problem, there is still the difficulty of handling hydrogen at very high pressure. This is not like a convenient liquid fuel. Commercial supplies of hydrogen are typically in cylinders at 300 to 750 bar. As far as I can find out, commercial supplies of LPG are typically in cylinders at 2 to 20 bar, depending on the gas composition. LPG tanks can be refilled a bit like petrol tanks, at a filling station, while you wait. Can you do tha
Re: (Score:2)
I do not know what the pressure is for hydrogen powered cars.
But they get refilled at "ordinary" gasoline stations here in Germany.
Re: (Score:2)
Re: (Score:2)
This really only makes sense if A+B is less than the cost of extracting and refining traditional jet fuel and can be done at the same scale. Otherwise, you're just using up tons of energy to unburn CO2 so that you can burn it again, for energy. Oh, it might also be worth while if the end product wasn't the same
perpetual motion nonsense (Score:3)
The article doesn’t mention amount energy input anywhere, but does say it recaptured “a few grams”
Re: (Score:2)
You can heat things other ways besides burning things. A resistive electrical heating element comes to mind. The problem with renewables for aviation is that batteries aren't energy dense enough compared to jet fuel. So make the jet fuel on the ground, perhaps inefficiently, but with a renewable energy source, such a solar. Then you have carbon-neutral aviation (at least for the fuel cycle).
Re: (Score:2)
Re: (Score:2)
They don't say it runs without energy input. Even at the end of the summary it says:
"And if you want effectively zero emissions, the capture and conversion systems would have to run on clean energy."
This is just about dealing with emissions where renewables currently fail: aircraft. Batteries are just too heavy, so instead use captured carbon like a [low efficiency] battery. Makes perfect sense to me... if they can make it practical.
Re: (Score:2)
We've been feed nonsense for decades. The entire 70's & 80's recycle plastic compaign was funded by the oil industry.
https://www.rollingstone.com/c... [rollingstone.com]
Look at the other “renewable” fuel, ethanol. Ethanol requires more energy to make than it produces. It’s a tax boondoggle. It’s fermented with lower energy propane, it’s s
Re: (Score:2)
Ethanol requires more energy to make than it produces.
Ethanol can be produced very efficiently, especially from sugar cane. [wikipedia.org] The problem the USA had is that the government tried to subsidize ethanol production from corn, which really wasn't viable.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
I'm not sure that makes sense (Score:2)
Old news (Score:2)
This Isn't New (Score:2)
All these processes highlight the need for one thi (Score:2)
Re: (Score:2)
Technological progress is too scary (Score:5, Insightful)
What pray tell would you use so much clean energy for that you can't spare some for elimination some portion(7%) of world's fossil fuel consumption? And if follow that if you can make avgas, then you could use a similar process make fuel for maritime shipping as well and start to get close to eliminating 10-20% of the world's reliance on fossil fuels.
At some point you have clean energy you need to apply it to more than running the lights in people's homes. You need to use it to transform farming, shipping, and all other industries. Even if you have to do it one at a time.
Re: (Score:2)
Re: (Score:2)
That would depend on the efficiency and price of the converter. It's competing against batteries, which are fairly efficient but also somewhat expensive.
Re: (Score:2)
Re: (Score:2)
Tesla battery Australia: It is also saves a small amount of power to be used in an emergency situation to stabilize the grid instantly.(to give the bigger players time to get going)
I would say it is not the median electric price you need to worry about. Only the cheapest hours you wish to run.
Re: (Score:2)
rendered unconscious? What pray tell do you think that even means. Do you think I'm a piece of fried chicken ready to be rendered into a delicious crispy mass?
Re: Rube Goldberg bullshit (Score:2)
No, the idea is to keep the air clean so we don't keep extincting entire species until it will be us.
Nobody cares if it expensive, inefficient or complicated.
And we are not Ferengi. We don't die for money.
You can go ahead and feed your kids a plate of profit-to-table Bitcoin in a 100 years though. :P
Re: (Score:2)
If you have clean energy available to power this process, there are a hundred other things you could do with it that would be much more useful than creating jet fuel
False. Jet fuel is an anchor in our carbon processes. You could take every car and truck off the road and we'd still need to keep digging up oil and refining it to keep planes in the sky. Hell you do you realise why during the early parts of the COVID pandemic petrol prices didn't drop more than a couple of cents? We actually had a *shortage* of fuel as refiners had to massively cut rates due to lack of storage for things like jet fuel.
If we ever hope to actually give up on fossil fuels then you will need t
Re: (Score:2)
You got close to the core of the issue, but not all of the way there:
When you refine a barrel of oil, you get a whole bunch of different things. Those include:
* Propane/Natural Gas
* Gasoline/Petrol
* Diesel
* Jet fuel/Kerosene
* Fuel oil/Bunker oil
* Lubricants
* Asphalt
* Charcoal briquettes
* Wax
And while you can do a bit of balancing to get more or less of some of those, ultimately every barrel of oil produces all of them. And if you need a lot more of one, you need a lot more oil. And you produce a lot more of
Re: (Score:2)
It's likely that we're going to get hit with massive price increases here and there as that economy dies. It's not going to be pretty.
That was precisely my point when I said that we need to address all the consumers of fossil fuels as we can't just consume some and ignore others.
To be clear we partially can do this, but the reality is even if we reconfigure refineries to shutdown fluidised cracking units and reformers and build them entirely out of hydrocrackers and merox units to produce jet fuel, we will always have a "wasted" byproduct and that byproduct will always get used for something that will always have an environmental impact.
H
Re: (Score:2)
The point is that this is not actually offsetting carbon dioxide emissions.
The carbon emissions come from generating the energy in the first place. This process is just moving the emissions around.
If we had a source of hydrogen that didn't come from fossil fuels (currently, hydrogen is made by stripping H2 off of methane, which is a fossil fuel), this might be a way to store solar energy in the form of jet fuel.
But that's not actually new; that's just liquid synfuel production from hydrogen. That's an old
Not quite (Score:2)
Jet A is mostly composed of a fraction that has most of the same hydrocarbons as kerosene. In other words, they are very similar, but not identical. Similar enough that you can substitute one for the other, though you wouldn't because the more highly refined jet fuel is more expensive.
About 75% of what's in diesel fuel is pretty much the same as what's in kerosene. That is, you could make diesel by mixing 75% kerosene and 25% various other stuff.
Re: (Score:2)
The major differences are lubricant additives (the diesel for trucks needs more, jets need none), and anti-coagulants (it's cold at 30k ft, and diesel/kerosene will thicken almost to a melting wax consistency).
As a truck driver, one of the ways to get into really big trouble is to be caught with red fuel. That is kerosene that has dye added, but not the road taxes. Don't mess with tax money. Other than that red dye, they're the exact same stuff.
Re: (Score:2)
There is more than that. Jet fuel has much more sulphur. Also it has no cetane rating.
Re: (Score:2)
Yes, kerosene is a diesel fuel, but not all diesel fuels are equal. You're not filling your F150 with #1 diesel (kerosene), and Delta isn't filling their 767s with #2 diesel next to you at the Shell station.
May as well say that petroleum-based solvents are the same thing as heavy gear oil. Sure, they're all distillates of raw petroleum, but very different in their uses and viability of use in systems designed around a particular distillate.
Re: (Score:2, Insightful)
Re: (Score:2)