Researchers built a perovskite and copper-based device that converts carbon dioxide into C2 products – precursory chemicals of innumerable products in our everyday lives, from plastic polymers to jet fuel.
The problem is the somewhat low atmospheric CO2 concentration; this is why all the "lets just pollute now and remove the CO2 from the atmosphere with some futuristic tech!" approaches are also kinda doomed, because even if you had some workable process that did not cause excessive costs by itself (like this one possibly), you still need to process millions of cubic meters of air, every year, just to compensate for a single (!!) car.
A 1200 CFM home air conditioning system moves roughly 20 million cubic meters per year.
Even from those numbers, you already get up to a football stadium of processed air per hour for every small town. For a big city, you need to process that football stadium worth of air every second.
Building infrastructure of that magnitude is a major commitment, and if most nations can not be arsed to replace a small number of fossil power plants per country, I honestly don't see us building large air processing plants in every single town in a timely manner (that are extremely likely to be less profitable than replacing the power plants).
Can it be coupled with current air processes?
Every house, office building and factory has air handling units.
Factories and other industrial sites also use compressors.
You can put it in pipes and send it to a central location, but you need pumps and the pipes are a nightmare.
You can store it in a local tank but you need a pump again, and burn it but it release the CO2 again. Using a solar panel and a battery is easier and more efficient.
(Do they need also some water pipes?)
For a distributed production, solar panels are much better.
Pipes and pumps may work in a centralized setup, but I'm still not convinced it's better that biodiesel or ethanol.
Photosynthesis is very inefficient, so there is a lot of room for improvement. But plants are like self building robots and they store the output in grains that are easy to transport.
Which would suggest that maybe as much as 0.1% to 1% of earth's atmosphere has ever passed through an air conditioner.
https://spectrum.ieee.org/efficient-airconditioning-by-beami...
Outer space is like really really cold. What we need is a huge heat pump in outer space that pumps the planets heat out into deep space. All we need is a space-elevator style tube and we're good to go!
Then I remembered that my dad didn't have indoor plumbing in his house for most of his childhood, and that 200 years is a much longer time than my first gut instinct.
Right now we don't have any CO2 scrubbing process without significant maintenance or operating costs, so this would add significant cost to all those ACs. Furthermore, the effect is marginal: With emissions of >6 tons of CO2/year/human, you would have to scrub a lot of air (>10m³/min with cost-free 100% efficiency, which is a pipedream) to compensate (for a single human); running the ACs on full flow all the time might not even be worth it depending on how efficient the scrubbing is and how clean the source of electricity.
You might say scrubbing clean 10m³/min of air for every human sounds kinda feasible, but just compare the realistic cost of such a setup to the options that are currently implemented, and how much popular resistance/feet dragging they already meet (renewables, nuclear power, electrification, CO2 taxation).
As a general benchmark, I would suggest that before the scrubbing technology in question has not managed to be installed at most major stationary sources of CO2 (coal/gas power plants, etc), it is not even worth discussing it for distributed air scrubbing.
We need all across the board solutions, and if you start requiring small scrubbers to function that can start to provide scale effects that can translate for bigger systems.
The problem with CO2 is that it's the most stable form.
Also, if you want to absorb the CO2, for 1 pound of fuel you get like 3 pounds of CO2. You can absorb it into a solid and the density is like 3 times the density of the fuel. So with a lot of approximations you need container that has the same volume than the fuel tank to store the CO2, or even bigger if you absorb it in a liquid or much much much bigger as a gas. And you must empty/exchange the container when you refuel. And then you realize that it's better to use an electric car.
If a technology is not good enough for at least serious trials in that (much simpler and more forgiving) usecase, then there is no point in discussing it for small environmental air scrubbing. That is akin to talking about electrifying passenger planes before having a single electric vehicle on roads.
That's not to say that we're there yet. Specialists in other countries still make a much better widget than the robot in my closet and they will for a while. But it's a step.