Petrol from thin air, snakeoil or...?

[DodgyGeezer]

https://www.popsci.com/environment/aircela-gasolin...

If this does as it says it could be interesting - the cynical in me however suspects the governments of the world would legislate it out of existence for Joe Public...

[delta0]

It can be done but there’s a couple of issues. First is the cost, it’s not remotely feasible at any scale. Second it is taking the CO2 out of the air but when you burn this fuel it creates other gases with GWP such as NOx which aren’t removed from the air. This means it doesn’t solve the sustainability equation. Net Zero applies to GWP not only CO2.

[paradigital]

Exactly. The process of splitting CO2 and using that to make fuel is energy inefficient. It would continue to make far more sense to just charge an EV. You think public EV charging is expensive, this would make that pale into insignificance.

[Paul Drawmer]

Well; it's still 'burning stuff' so the emissions of the vehicle it's used in won't change, only the fuel supply side which is often ignored anyway.

Also, no mention is made of the power efficiency. Just how much electricity is consumed in making the petrol?

[Austin Prefect]

Essentially you are using a tank of petrol as a battery. A pretty good battery in many ways but expensive to charge.

[phil4]

CO2 in the atmosphere is only 0.04%... imagine the volume of air you're going to need to "process" to get any meaningful amount of the stuff.

[Terminator X]

phil4 said:

CO2 in the atmosphere is only 0.04%... imagine the volume of air you're going to need to "process" to get any meaningful amount of the stuff.

0.0004%

TX.

[phil4]

? Where did I go wrong, genuinely interested.

[Austin Prefect]

Terminator X said:

phil4 said:

CO2 in the atmosphere is only 0.04%... imagine the volume of air you're going to need to "process" to get any meaningful amount of the stuff.

0.0004%

TX.

No 0.04%, and trees manage to process it successfully.

[otolith]

Terminator X said:

phil4 said:

CO2 in the atmosphere is only 0.04%... imagine the volume of air you're going to need to "process" to get any meaningful amount of the stuff.

0.0004%

TX.

Err, no.

Composition of air is key stage 3 science. That’s 11-14 year olds. Who can confirm that Phil is right.

[phil4]

Ok, I think I know what's going on.

I think TX has taken 420 odd PPM, and assumed the % is 420/1,000,000 ie. 0.0004%.

PPM to % doesn't work like that, % is parts per hundred... so 420ppm is 420/1,000,000 x 100. = 0.04%

I think.

[Megaflow]

delta0 said:

It can be done but there s a couple of issues. First is the cost, it s not remotely feasible at any scale. Second it is taking the CO2 out of the air but when you burn this fuel it creates other gases with GWP such as NOx which aren t removed from the air. This means it doesn t solve the sustainability equation. Net Zero applies to GWP not only CO2.

This.

It is also entirely self defeating. If, and it is a big full bodied if, CO2 capture becomes cheap enough for this to become economically viable (hint, it won't) then the real irony is you won't need the fuel made from air, as you can carry on burring fossil fuels and capture the CO2 that results.

[kambites]

Isn't this exactly what's meant by an "e-fuel"? The idea has been around for ages and it works fine, provided you don't mind putting in roughly 10 times as much energy in the form of electricity as you get out in power at the wheels.

So when we have enough renewable energy generation not only cover all of our current usage electricity, but also roughly 10 times our automotive energy usage, it might be plausible for the mainstream. Until then it'll allow the super-rich to continue running their toys whilst telling themselves they're being environmentally friendly.

[Terminator X]

otolith said:

Terminator X said:

phil4 said:

CO2 in the atmosphere is only 0.04%... imagine the volume of air you're going to need to "process" to get any meaningful amount of the stuff.

0.0004%

TX.

Err, no.

Composition of air is key stage 3 science. That s 11-14 year olds. Who can confirm that Phil is right.

Kick a man when he is down

The UK %age

TX.

[otolith]

Terminator X said:

Kick a man when he is down

The UK %age

TX.

That number doesn’t matter though, it was about the amount available to the machine at point of use, so it doesn’t make any difference if what you’re sucking up is natural or man-made, it’s all mixed up together.

[kambites]

otolith said:

That number doesn t matter though, it was about the amount available to the machine at point of use, so it doesn t make any difference if what you re sucking up is natural or man-made, it s all mixed up together.

I guess the obvious thing to do is install such systems into the exhaust path of something burning fossil fuels where the CO2 is very concentrated.

[TheDeuce]

It's as if people are amazed that chemistry exists. You can create useable fuels from all sorts of convoluted processes, but it requires energy to complete those processes! If the energy used is electricity or can be used to directly generate electricity instead... then out the electricity directly into an electric car!

That's ignoring the fact that any fuel that has to be burned is obviously not 'clean', however it was produced, also that fuel has to be transported ahead of use, which is further inefficient and has a £ and carbon cost.

All these ideas work, but they're all pointless.

[DMZ]

I bet you somebody with a spreadsheet could have a crack at figuring out how pointless it is. Compare let’s say a used diesel car (that has sunk CO2 manufacturing “cost”) running on HVO vs replacing it with a built with coal power Chinese EV that then runs off an imperfect grid. Assuming any of this actually matters.

[GT9]

Paul Drawmer said:

Well; it's still 'burning stuff' so the emissions of the vehicle it's used in won't change, only the fuel supply side which is often ignored anyway.

Also, no mention is made of the power efficiency. Just how much electricity is consumed in making the petrol?

It's just e-fuel on a tiny scale.

The hydrogen in the fuel comes from electrolysis of water and requires both a copious supply of electricity as well as the water supply, which, surprise, surprise, was glossed over in the article.

Industrial scale e-fuel has been struggling to break through the 10% well-to-wheel efficiency barrier, and might eventually get to 13% or thereabouts. In the case of e-fuel ‘well’ means wind turbine or equivalent.

Fossil fuelled ICEs are in the range of 15-20% well-to-wheel efficiency, diesel being higher than petrol.

Microscale e-fuel will likely be sub 10%.

Compare that to using the same amount of electricity to charge an EV, and you can expect to go up to 10 times further in the EV than a micro-scale e-fuelled ICE car...

Whilst these sorts of products might appeal to STEM illiterate punters, there is nowhere near enough electrical capacity anywhere on earth that could make something like this viable on a popular scale, ignoring the stupidly high cost of the electricity you'd be paying for.

Edited by GT9 on Friday 30th May 07:06

[TheDeuce]

DMZ said:

I bet you somebody with a spreadsheet could have a crack at figuring out how pointless it is. Compare let s say a used diesel car (that has sunk CO2 manufacturing cost ) running on HVO vs replacing it with a built with coal power Chinese EV that then runs off an imperfect grid. Assuming any of this actually matters.

The used diesel will be worse than the EV during its lifetime, easily. I'm honestly not sure if 'petrol' from the atmosphere would be even more or slightly less damaging. But it really doesn't matter - EV's are here now and are easily proven to be cleaner overall.

But for all the proof in the world, and for whatever spreadsheet effort some members may make, it will fall on deaf ears won't it? Some folk just don't like change, aren't interested in progress and subsequently are totally closed minded to the benefits. These people don't require proof, they only need the DM pointing to how 'dirty' batteries are and they feel their ignorant opinion has been suitably validated.