Scientists at Northwestern University have developed a groundbreaking way to make concrete and cement more eco-friendly.
By using seawater, electricity, and carbon dioxide (CO2), they have created a new building material that helps fight climate change.
A smarter way to use CO2
Many researchers around the world are trying to capture CO2 from the air and store it underground.
While this helps reduce greenhouse gases, it doesn’t make the best use of CO2. The Northwestern team took a different approach: they found a way to turn CO2 into valuable materials for construction, such as concrete, cement, plaster, and paint.
Even better, their process also produces hydrogen gas, which is a clean fuel that can be used in transportation and other industries. Their study was recently published in the journal Advanced Sustainable Systems.
The key to this innovation is seawater. The researchers applied an electric current to seawater, which split water molecules into hydrogen gas and hydroxide ions.
Then, they bubbled CO2 through the seawater, increasing the amount of bicarbonate ions in the water. These ions reacted with naturally occurring minerals, such as calcium and magnesium, to form solid materials like calcium carbonate and magnesium hydroxide.
This process is similar to how corals and mollusks build their shells, except instead of using biological energy, the scientists used electricity to speed up the process. The resulting materials can replace sand in concrete, helping to trap CO2 while making construction more sustainable.
One of the most exciting discoveries was that the scientists could control the properties of the new material by adjusting the electric current, CO2 flow, and seawater circulation.
This means they can create different types of materials—some more porous and lightweight, others denser and stronger—depending on what is needed for construction.
These materials could be used to replace sand and gravel in concrete, or they could be used to make cement, paint, and plaster.
Because sand is currently mined from rivers, mountains, and ocean floors, this innovation offers a more sustainable way to source materials without harming the environment.
A big step for the cement industry
The cement industry is responsible for about 8% of the world’s CO2 emissions. If this new process is widely adopted, it could significantly reduce the environmental impact of cement and concrete production.
The researchers suggest that factories could set up reactors near the ocean to use seawater and CO2 from industrial emissions to create these new materials. This would create a circular system where CO2 is captured and turned into useful building materials instead of being released into the atmosphere.
By using CO2 to create strong, durable building materials, this new approach could help make construction much more sustainable. Not only does it reduce emissions, but it also turns a major pollutant into something useful.
With continued development, this technology could play a big role in fighting climate change while keeping up with global demand for building materials. It’s an exciting step toward a greener future!
