Stanford University chemists have made an exciting breakthrough in the fight against climate change. They’ve created an affordable method to remove carbon dioxide (CO2) from the atmosphere. This process could play a big role in reducing global warming.
The team discovered that by using heat, common minerals can be transformed into materials that absorb CO2 naturally. These minerals can be made using traditional kilns, similar to those used in cement production.
Matthew Kanan, a Stanford chemistry professor, explained, “The Earth has plenty of minerals that can remove CO2, but they don’t react quickly enough to make a difference.” Their new method speeds up this process, making it scalable and effective.
In nature, minerals like silicates slowly react with water and CO2 to form bicarbonates and carbonates through a process called weathering. Unfortunately, this reaction can take hundreds to thousands of years. Scientists have been looking for ways to speed this up since the 1990s.
To tackle this challenge, Kanan and postdoctoral scholar Yuxuan Chen developed a method to activate these minerals, making them more reactive. Chen described their approach as a simple ion-exchange reaction that exceeded their expectations.
While technologies exist to capture CO2 directly from the air, many are costly and energy-heavy. Kanan believes their method will be less energy intensive and more economical in the long run.
To create their carbon-absorbing minerals, the researchers borrowed from cement production techniques. Cement is made by heating limestone to produce calcium oxide, which is then mixed with sand. Instead, the Stanford team used calcium oxide combined with silicates that contain magnesium. When heated, these minerals transformed into magnesium oxide and calcium silicate. These new minerals react quickly with CO2.
The team conducted tests showing that, in just a few hours, their materials could capture CO2. Even in realistic conditions with lower CO2 levels, they significantly outpaced natural weathering processes.
There’s also potential for these minerals to benefit agriculture. Kanan suggests that spreading magnesium oxide and calcium silicate over fields might not only remove CO2 but also improve soil health. As these minerals break down, they can increase soil alkalinity and provide silicon, which improves crop yields. Farmers might find this approach valuable, as it could replace the need for traditional soil amendments.
The researchers currently produce 15 kilograms of these materials each week. However, existing kiln technology used in cement production could scale up production dramatically. There are massive amounts of suitable silicate minerals available worldwide, especially as mining byproducts.
According to Chen, over 400 million tons of suitable mine tailings are produced globally each year, presenting a rich source of materials. With an estimated 100,000 gigatons of olivine and serpentine available, there’s immense potential for carbon removal.
After factoring in emissions from kiln operations, the researchers believe their method could effectively remove one ton of CO2 for every ton of reactive material produced. They are now developing electric kilns to minimize fossil fuel use and are actively seeking funding to bring this research into practical applications.
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Climate,Breakthroughs,Carbon,Geology,Global Warming,Emissions
