It is an idea as simple as it is revolutionary: cool the air to capture carbon dioxideusing low -cost porous materials and a cold source that is already often wasted today. It is not about science fiction, but of A new technology developed by a team of researchers from the Georgia Institute of Technologywhich could make the Direct capture of the CO₂ More accessible, less expensive and above all more widespread in the world.
The method, presented in the scientific journal Energy & Environmental Sciencewas born from a simple question: What would happen if we used the frost of liquefied natural gas to cool the air and capture the CO₂ more efficiently? The answer could change the cards on the table in the fight against climate change.
So the CO₂ remains trapped and the air is released
To understand how this discovery works, you have to start from Liquefied natural gas (GNL). It is cooled to become liquid to be transported by ship, and then heated again Before use, through a process called relevance. At this stage it is produced a lot of cold – cold that is usually thrown awaydispersed at sea with cooling water.
And this is where the brilliant intuition arrives: Why not use that frost to cool the air and capture carbon dioxide in an easier and cheaper way? By cooling the air up to -78 ° C, much of the humidity condenses and disappears. This creates The ideal conditions for “physisorbents”porous materials that absorb co₂ without the need for chemical reactions and without the high energy expenditure required by traditional systems.
No complicated chemicals, no difficult processes to maintain over time: only economic materials, already on the market, and a cold that otherwise should be wasted.
Zeolite 13x and Calf-20
The protagonists of this technology are two materials already known in the world of industry: The zeolite 13x and the Calf-20. The first is a porous powder used in water filters, resistant and cheap. The second is a metal-organic material (MOF) capable of retaining with great efficiency.
In the laboratory, the researchers found that At -78 ° C both these materials manage to capture up to three times more carbon dioxide than administrative systemsthe most used today for direct capture from the air. But there is more: They release the Co₂ captured with a very low energy consumptionmaking the process more sustainable also from an economic point of view.
According to the calculations of the team, The cost to capture a ton of CO₂ could drop up to 70 dollarsagainst over 200 dollars of current methods. A drastic reduction which could really make the difference.
The technology that can become global
Another strong point of this discovery is that: just use the infrastructures already present in the ports where the GNL arrives. The regasification terminals are found in many coastal areas of the worldand could become real centers of the CO₂.
This expand the geographical areas in which the DAC can workbecause today the most common systems only work in dry and fresh areas. Instead, thanks to the cold of the GNL, We could absorb CO₂ even in humid and temperate environmentswhere it was almost impossible so far.
According to the researchers, it would be enough to take advantage of even a part of the cold energy available in the Gnl terminals for capture over 100 million tons of Co₂ every year by 2050. A huge number, which could help governments and companies achieve zero emissions goals.
Finally, lowering the air temperature, it becomes possible to use many more materials for the capture of the CO₂thus expanding the range of available technologies and reducing costs even more.
