3 Key Takeaways:

1. Researchers at Newcastle University have developed a pioneering membrane that captures and concentrates carbon dioxide (CO2) from the air using ambient energy and natural humidity differences.

2. This innovative technology was created through a collaboration of leading universities, employing advanced techniques like X-ray micro-computed tomography to optimize the membrane’s performance.

3. The membrane’s ability to efficiently capture CO2 is crucial for achieving climate targets and could drive a circular economy by supplying CO2 for carbon-neutral or carbon-negative hydrocarbon production.

Innovative Technology from Newcastle University Uses Natural Humidity Differences to Transform Carbon Capture Efficiency

Researchers at Newcastle University have developed a groundbreaking ambient-energy-driven membrane that effectively extracts carbon dioxide (CO2) from the air. This innovation could play a crucial role in addressing climate change.

Direct air capture has been recognized as one of the “Seven Chemical Separations to Change the World,” and for good reason. Despite CO2 being the primary driver of global warming—with approximately 40 billion tons released into the atmosphere each year—capturing it directly from the air is notoriously difficult due to its low concentration of around 0.04%.

Professor Ian Metcalfe, Royal Academy of Engineering Chair in Emerging Technologies at Newcastle University’s School of Engineering, explains the challenge: “Dilute separation processes are among the most difficult to achieve for two main reasons. First, the low concentration means the chemical reactions required to remove the target component occur very slowly. Second, concentrating the dilute component demands a significant amount of energy.”

This new membrane technology, by harnessing ambient energy, offers a promising solution to these challenges, paving the way for more efficient and sustainable CO2 capture from the atmosphere.

Researchers from Newcastle University, in collaboration with colleagues from Victoria University of Wellington, Imperial College London, Oxford University, Strathclyde University, and UCL, have tackled two major challenges in direct air capture with their innovative membrane process. By harnessing naturally occurring humidity differences, they found a way to pump carbon dioxide (CO2) out of the air without the heavy energy demands typically required. The presence of water also accelerates the transport of CO2 through the membrane, addressing the slow kinetics of the separation process.

This groundbreaking work, published in Nature Energy, represents a significant advancement in CO2 capture technology. Dr. Greg A. Mutch, Royal Academy of Engineering Fellow at Newcastle University, explains the broader impact: “Direct air capture will be a crucial part of the future energy system. It’s essential for capturing emissions from mobile, distributed sources of CO2 that are difficult to decarbonize by other means.”

Dr. Mutch further describes the innovation: “We’ve developed the first synthetic membrane that can capture CO2 from air and concentrate it without relying on traditional energy inputs like heat or pressure. A helpful analogy might be a water wheel on a flour mill. Just as a mill uses the downhill flow of water to drive milling, we use natural humidity differences to pump CO2 out of the air.”

This breakthrough offers a promising, energy-efficient method for addressing one of the most pressing challenges in the fight against climate change.

“In our research, we’ve developed the first synthetic membrane that can capture carbon dioxide (CO2) from the air and increase its concentration without relying on traditional energy inputs like heat or pressure,” explains the team behind this innovative breakthrough. Dr. Greg A. Mutch likens this process to a water wheel on a flour mill: just as the wheel uses the downhill flow of water to drive milling, their membrane leverages natural humidity differences to pump CO2 out of the air.

Separation processes like this are fundamental to modern life. Whether it’s the food we eat, the medicines we take, or the fuels and batteries that power our vehicles, most products we use undergo several separation processes. These processes are not just about creating products; they’re also vital for minimizing waste and reducing the need for environmental cleanup efforts, such as direct air capture of CO2.

As the world shifts towards a circular economy, separation processes will become even more crucial. In this new model, direct air capture could be used to provide CO2 as a feedstock for producing hydrocarbon products in a carbon-neutral or even carbon-negative cycle.

Achieving climate goals, like the 1.5°C target set by the Paris Agreement, will require more than just a transition to renewable energy and traditional carbon capture from point sources like power plants. Direct air capture will be an essential tool in our arsenal, helping to ensure we can meet these critical targets and address the ongoing challenge of climate change.

The innovative humidity-driven membrane developed by researchers at Newcastle University represents a significant departure from traditional membrane technology. Dr. Evangelos Papaioannou, Senior Lecturer in the School of Engineering, explains, “In a novel approach detailed in our research, we tested a new carbon dioxide-permeable membrane under various humidity conditions. Remarkably, when the humidity on the output side of the membrane was higher, the membrane spontaneously pumped carbon dioxide into that output stream.”

To fully understand and optimize this process, the team collaborated with researchers at UCL and the University of Oxford, utilizing X-ray micro-computed tomography to precisely characterize the membrane’s structure. This detailed analysis allowed them to make robust performance comparisons with other cutting-edge membranes.

A critical component of the research involved modeling the molecular processes occurring within the membrane. Using density-functional-theory calculations, conducted with a collaborator from both Victoria University of Wellington and Imperial College London, the team identified unique ‘carriers’ within the membrane. These carriers transport both carbon dioxide and water—but nothing else. The interaction between these two molecules is key: water is needed to release carbon dioxide from the membrane, and carbon dioxide is needed to release water. This interplay allows the energy from a humidity difference to drive CO2 through the membrane, concentrating it from a low to a higher concentration.

Professor Ian Metcalfe emphasizes the collaborative nature of the project: “This was truly a team effort over several years, and we are deeply grateful for the contributions from our collaborators and the support from the Royal Academy of Engineering and the Engineering & Physical Sciences Research Council.”

This breakthrough highlights not only the membrane’s potential in tackling climate change but also the power of interdisciplinary collaboration in advancing scientific frontiers.