Researchers have developed a reactor that pulls carbon dioxide directly from the air and converts it into sustainable fuel, using sunlight as the power source

[u/Wagamaga]

https://www.cam.ac.uk/research/news/solar-powered-device-captures-carbon-dioxide-from-air-to-make-sustainable-fuel

[u/Wagamaga]

The researchers, from the University of Cambridge, say their solar-powered reactor could be used to make fuel to power cars and planes, or the many chemicals and pharmaceuticals products we rely on. It could also be used to generate fuel in remote or off-grid locations.

Unlike most carbon capture technologies, the reactor developed by the Cambridge researchers does not require fossil-fuel-based power, or the transport and storage of carbon dioxide, but instead converts atmospheric CO2 into something useful using sunlight. The results are reported in the journal Nature Energy.

Carbon Capture and Storage (CCS) has been touted as a possible solution to the climate crisis, and has recently received £22bn in funding from the UK government. However, CCS is energy-intensive and there are concerns about the long-term safety of storing pressurised CO2 deep underground, although safety studies are currently being carried out.

“Aside from the expense and the energy intensity, CCS provides an excuse to carry on burning fossil fuels, which is what caused the climate crisis in the first place,” said Professor Erwin Reisner, who led the research. “CCS is also a non-circular process, since the pressurised CO2 is, at best, stored underground indefinitely, where it’s of no use to anyone.”

“What if instead of pumping the carbon dioxide underground, we made something useful from it?” said first author Dr Sayan Kar from Cambridge’s Yusuf Hamied Department of Chemistry. “CO2 is a harmful greenhouse gas, but it can also be turned into useful chemicals without contributing to global warming.”

https://www.nature.com/articles/s41560-025-01714-y

[u/CliffordTheBigRedD0G → u/Wagamaga]

I just watched a video yesterday about making concrete pavers that are cured with CO2 instead of water. Companies like that would probably like having something like this I'd imagine.

[u/Ndvorsky → u/CliffordTheBigRedD0G]

Concrete is normally cured with CO2 & water.

[u/ImSuperHelpful → u/Wagamaga]

If they convert it to fuel as they’re describing, doesn’t the CO2 just get rereleased once that fuel is used?

The other major problem is that the capture is about 8-9% effective, they captured about 84mg of CO2 per gram of material per day (in specific laboratory conditions, if I read it right). Even if it somehow magically gets to 1:1, there’s no way to build installations at a scale large enough or fast enough to matter (we need to remove billions and billions of tons on top of all of the new emissions).

This might have great niche applications, but unfortunately I think they’re just trying to cash in on false climate change promises. Or they think we have hundreds of years to solve this problem, I guess.

[u/A-Grey-World → u/ImSuperHelpful]

It gets released, yes. But that doesn't matter. If efficient enough, because it would be a carbon neutral fuel source. A big problem with solar is storage (and it's location/season dependant). Bio fuels work on the same mechanism (carbon dioxide and sunlight -> carbon based fuel) so is also carbon neutral but requires lots of water.

Something like this could be great for desert areas. Produce truly carbon neutral fuel, ship it to other places for use.

[u/ImSuperHelpful → u/A-Grey-World]

That’s all well and good, but absolutely negligible towards global warming. They’re piggybacking on the carbon capture fad for hype and making direct comparisons to underground storage, but in the end they aren’t actually capturing anything since it gets released right back. That’s what I’m criticizing. (And that it’s impossible to scale to a meaningful level in that same conversation)

Edit I should add that we know new sources of clean energy don’t shut down dirty sources… capacity is only added, never replaced. Consumption must always rise under capitalism (which is why a carbon neutral source of fuel doesn’t matter… we’re building wind and solar like crazy but fossil fuel consumption continues to rise)

[u/buttsparkley → u/ImSuperHelpful]

Well hold on it would be recaptured, we would use less of fuels that release it , so this way we could atleast stay where we are instead of making it worse, it bides us time. Once it's being used as energy (in many forms), there will be a certain % that will be constantly in storage waiting for usage eg propane, methane or even ethanol.

We can also store the CO2 in different ways, putting it back underground in oil reserves or water alternatives, we can learn to create closed systems grabbing the c02 and trapping it into a cycle in said system.

It can be turned into solid format that can be used for construction material.

It provides us with options , there is no point sitting here and saying ,this solution isn't perfect , ditch it , oh no I don't have a better solution I just don't believe in this one. Planting more trees inst going to fix this problem , we are unfortunately more effectient at polluting at the moment. Once we no longer add but recycle , then planting trees will mean something, alot actually. It's like pressing the pause button before reversing.

[u/Korchagin → u/ImSuperHelpful]

Yes. But there are some applications where we will need fuel for the foreseeable future, e.g. aircraft or oceangoing ships. There is no technology on the horizon with the potential to replace combustion engines there. A method to produce fuel for these from CO2 does help a lot - at the moment it's all produced from fossils.

If the method produces more than needed for that, it can also replace oil in the chemical industry. If there's still something left, we could simply revert the oil drilling and store it underground. But we're still very far away from having this luxury problem...

[u/SatoriFound70 → u/ImSuperHelpful]

But it isn't just about creating enough to matter. If we created and used as much fuel from this as possible that cuts down on the fuel that needs to be refined using less environmentally friendly methods. Yes we still have pollution when it is burned, but we have cut down on some pollution in the process of creating it, so it is a net lower carbon cost to drive. They aren't suggesting being able to take ALL CO2 out of the atmosphere that needs to be removed.

Every step we take that reduces the carbon footprint of mankind will help. If we take enough steps it will make a difference.

[u/moschles → u/Wagamaga]

say their solar-powered reactor could be used to make fuel to power cars and planes,

Right -- but the reactor does not emit gasoline. It produces syngas. https://en.wikipedia.org/wiki/Syngas

[u/ChicagoDash → u/Wagamaga]

Trees already convert CO2 into something very useful to both nature and man.

[u/Opie67 → u/ChicagoDash]

Horses already haul people and supplies, who needs cars

[u/someone_actually_ → u/ChicagoDash]

Plus wood and fruit as secondary and tertiary byproducts

[u/nsaisspying → u/ChicagoDash]

We (as a species) can do more than one thing at the same time.

[u/Excession638 → u/ChicagoDash]

Wood is a pretty bad fuel though. It's bulky, heavy, polluting to burn, and needs more energy to dry it out first. The Syngas (hydrogen and carbon monoxide) that this process produces isn't without issues either though.

[u/patentlyfakeid → u/Excession638]

Fairly certain they were referring to oxygen and not cellulose.