Capturing carbon dioxide (CO2) from industrial emissions is considered one of the key tools for fighting climate change.
However, today’s carbon capture technologies are often expensive, energy-intensive, and difficult to expand on a large scale.
Now, researchers at MIT have developed a promising new approach that could make carbon capture more efficient and flexible in the future.
The research, published in Nature Energy, explores an alternative method known as electrochemically mediated carbon dioxide capture, or EMCC.
The work was carried out by a team of MIT scientists with support from the MIT Climate and Sustainability Consortium.
Most current carbon capture systems rely on a process called amine scrubbing. In this method, chemical compounds known as amines absorb CO2 from industrial exhaust gases.
While effective, the process requires large amounts of heat to release the captured CO2 so it can be stored or reused. This high energy demand increases costs and limits large-scale deployment.
The MIT team is investigating a different strategy that uses electricity instead of heat to capture and release carbon dioxide. In principle, this electricity could come from renewable sources such as solar or wind power, making the process more environmentally friendly.
However, existing EMCC systems have their own challenges. Many rely on materials called sorbents that require extremely strong electrical conditions to operate. These conditions can trigger unwanted side reactions, particularly involving oxygen, which reduce efficiency and can damage the system over time.
To address this problem, the researchers tested a new class of carbon-capturing molecules known as N-heterocyclic imines, or NHIs. These molecules have attracted attention because their chemical properties can be modified relatively easily, allowing scientists to fine-tune their performance.
The MIT researchers found that NHIs could be used in an electrochemical carbon capture system through a unique mechanism that avoids the need for highly reducing electrical conditions. This could help improve efficiency and reduce some of the technical limitations that have slowed the development of EMCC technologies.
The team also designed a new molecular structure called bis(NHI). According to the researchers, this structure could theoretically capture two molecules of carbon dioxide for every electron involved in the process, potentially improving efficiency.
Although the technology is still in the early research stage, the results suggest that further molecular engineering could make the system work in a wider range of operating conditions. This flexibility could help scientists optimize future systems for lower energy use, higher efficiency, and greater reliability.
The researchers say one of the next major challenges is understanding how the bis(NHI) molecules change and degrade during long-term operation. By identifying these degradation pathways, they hope to design more durable versions that can withstand repeated cycles of carbon capture and release.
If successful, the technology could provide a more energy-efficient way to remove carbon dioxide from industrial emissions, helping reduce greenhouse gases while lowering the cost of carbon capture.
Source: KSR.
