Researchers in Finland have found a new way to capture carbon dioxide from ambient air that they say is more efficient than existing methods, cheap to produce, reusable, and allows for easy recycling of captured CO₂. 

The team, led by University of Helsinki post-doctoral researcher Zahra Eshaghi Gorji, published the findings from their research on a compound of superbase material 1,5,7-triazabicyclo [4.3.0] non-6-ene (TBN) and benzyl alcohol last month. In their testing, the team found that the TBN-BA liquid compound stood out "in both molar and gravimetric capture capacities," and that it didn't react with nitrogen, oxygen, or other atmospheric gases, suggesting a promising discovery for the future of direct air CO₂ capture.

Direct air capture of carbon dioxide isn't a new idea - there are plenty of technologies out there that can do it already. Aside from its high absorption rate - around 156 milligrams of CO₂ can be absorbed per gram of the TBN-BA compound - Gorji's compound is also a prime candidate for commercialization because it releases its captured CO₂ at a low temperature.

As the researchers point out in the paper, some existing direct air capture CO₂ absorbents require temperatures of around 900 °C (1,652 °F) to release captured carbon dioxide, which makes regeneration highly energy-intensive.

"An ideal absorbent should strongly bind CO₂ during capture yet enable its release with minimal energy input," the team said, and the TBN-BA compound, among a number they tested, seems to fit the bill, as it needs just 30 minutes of exposure to 70°C (158°F) air to release its CO₂.

"After the first cycle, the absorption capacity decreased by about 25%, so we estimate that approximately 75% of the CO₂ was recovered," Eshaghi Gorji told The Register in an email. "After the second cycle, however, almost all CO₂ is removed." 

That suggests the TBN-BA compound was releasing pretty much all the CO₂ it captured after just around an hour of moderate heat. Better yet, it can be reused multiple times - the researchers found that the compound retained 75 percent of its absorption capacity after 50 capture/release cycles, and 50 percent after 100 cycles. 

Once you've reclaimed CO₂, you can use it to create numerous other products, including certain types of plastics or methanol fuel.

TBN-BA is also non-toxic, according to the researchers, and the material isn't expensive to produce, either. 

According to the University of Helsinki, the team is now working toward "near-industrial scale" tests. Those will require that a solid version of the TBN-BA compound be produced, however, which Eshaghi Gorji told us is still a work in progress.

"We are trying to incorporate this liquid sorbent into solid structures such as silica and graphene oxide to create a solid sorbent," Eshaghi Gorji said. "We also have access to a pilot-scale setup for solid sorbents for direct air capture (DAC), which allows us to evaluate their performance at a larger scale." 

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In other words, while it's a promising compound for future direct air capture of carbon dioxide, it's not going to appear in commercial or industrial applications anytime soon. 

Eshaghi Gorji herself is currently on parental leave and won't return to work until October 2026, and while the team that worked on the project hasn't entirely closed up shop, things might be delayed until she returns, at which time she said she intends to continue work on the pilot scale project. 

"This technology is currently at the laboratory-scale research stage," Eshaghi Gorji added. "Developing a commercial product requires significant time, funding, and effort. We are working toward this goal, particularly with solid sorbents, but it is difficult to estimate a timeline." 

Given fossil fuel emissions of CO₂ reached an all-time high in 2025, driven in part by datacenters that are demanding power as quickly and cheaply as they can get it despite clean energy plans, better carbon dioxide absorption on the cheap can't come fast enough. ®