University of Helsinki scientists unveil a promising liquid sorbent that captures CO₂ efficiently at low energy, aiming to address cost and sustainability barriers in direct air capture technology.
Researchers at the University of Helsinki have reported a promising new liquid sorbent for direct air capture (DAC) of carbon dioxide. The team says this combines high uptake, low‑energy regeneration and reuse potential. These are attributes that, if realised at scale, could help lower the costs and energy penalties that have dogged many DAC approaches.
The work, led by post‑doctoral researcher Zahra Eshaghi Gorji, centres on a superbase–alcohol compound formed from 1,5,7‑triazabicyclo[4.3.0]non‑6‑ene (TBN) and benzyl alcohol (TBN‑BA). The authors report that one gram of the liquid sorbent can absorb about 156 milligrams of CO₂ from untreated ambient air and that the compound “didn’t react with nitrogen, oxygen, or other atmospheric gases,” making it selective for CO₂ capture. The team highlights a further practical advantage: captured CO₂ can be released at modest temperature. As The Register noted, the compound “needs just 30 minutes of exposure to 70°C (158°F) air to release its CO₂,” a far lower regeneration temperature than some sorbents that require very high heat.
The University of Helsinki’s own account of the research echoes those performance claims, emphasising recyclability and the cleanness of CO₂ recovery. The researchers told The Register that after the first capture–release cycle “the absorption capacity decreased by about 25%, so we estimate that approximately 75% of the CO₂ was recovered,” and that “after the second cycle, however, almost all CO₂ is removed.” Reuse testing showed the material retained about 75% of its absorption capacity after 50 cycles and roughly 50% after 100 cycles, indicating durability but also clear degradation that must be addressed for long‑lived commercial use.
The Helsinki group is explicit that the work remains at laboratory scale and that translation to industrial use will demand further development. According to The Register, the team is pursuing conversion of the liquid sorbent into solid forms by incorporating it into supports such as silica and graphene oxide, because operating DAC systems typically favour solid sorbents for handling and process integration. The University’s SuperBase Solutions project is already working on scalable, economical production methods for superbase compounds, aiming to accelerate manufacture, quality control and regulatory compliance for industrial applications.
Independent research and technical literature underlines both the potential and the practical challenges the Helsinki approach seeks to address. A U.S. Department of Energy technical report on low regeneration temperature sorbents examines the use of catalysed amine systems and ionic liquids to improve absorption/desorption kinetics and reduce energy requirements, and presents conceptual process designs and preliminary economics suggesting catalysed sorbents could cut DAC costs if scaled effectively. Oak Ridge National Laboratory has explored an alternative route, near‑cryogenic DAC using physisorbents such as zeolite 13X and CALF‑20 at sub‑ambient temperatures, finding potential for substantially lower levelised costs when low‑temperature operation and suitable adsorbents are paired. Published studies on zeolites likewise show that low‑temperature deployment can make inexpensive physisorbents competitive for ambient CO₂ removal in cold, dry conditions. Other work has examined hybrid routes, for example coupling absorbents with electrochemical regeneration to release CO₂ at room temperature, sidestepping heat‑intensive desorption.
Those wider studies underline a familiar trade‑off in DAC development: chemical sorbents that bind CO₂ strongly at ambient conditions often demand high energy or complex processes to release the gas, while physisorbents can be easier to regenerate but may require low temperatures or larger plant footprints. The Helsinki TBN‑BA compound seeks a middle path, a chemical sorbent with relatively low desorption temperature, but its reported cycle‑life deterioration and the current need to convert a liquid formulation into a workable solid sorbent are obstacles the team must overcome to demonstrate commercial feasibility.
The Helsinki researchers and their institutional materials also stress non‑toxicity and low production cost for TBN‑BA. The SuperBase Solutions initiative claims the group has made progress toward industrial‑scale production of superbase compounds, including efforts to build an automated prototype system. Such manufacturing advances would be important if a TBN‑BA‑based solid sorbent were to be deployed at scale, given that any meaningful contribution to climate mitigation requires very large volumes of material.
Timing and resource constraints could influence progress. The Register reported that Eshaghi Gorji is on parental leave until October 2026 and that the project’s move to pilot‑scale testing will continue as team capacity permits. The researchers acknowledge that “developing a commercial product requires significant time, funding, and effort” and declined to provide a firm timeline.
Industry and policy context elevates the urgency: The Register observed that fossil fuel CO₂ emissions reached a record high in 2025, a trend driven in part by rising power demand from data centres and other energy‑intensive users. That backdrop helps explain why low‑cost, low‑energy CO₂ capture materials attract attention, even modest reductions in the energy required to regenerate sorbents, or improvements in cycle life, can materially affect the levelised cost of capture and the lifecycle emissions of DAC facilities.
At present, the Helsinki TBN‑BA result is a laboratory‑scale advance that adds a potentially useful option to the portfolio of DAC chemistries. According to the University of Helsinki, the next steps are conversion to solid sorbents and performance trials in a pilot‑scale DAC setup. Whether those demonstrations can close the remaining gaps, durability under many capture–release cycles, practical solid‑sorbent integration, and validated economics at scale, will determine if the compound moves from scientific promise to an industrial tool for climate mitigation.
