Hongyan Ma, associate professor of civil engineering at Missouri S&T.

Man-made rocks show promise as a carbon capture solution

Scientists and entrepreneurs across the world are working on innovations to reduce the amount of carbon dioxide in the atmosphere and ease the gas’s impact on climate change. While some focus on preventing CO2 from being released in the first place, such as with low- or no-carbon transportation technologies, others are perfecting methods for grabbing CO2 directly from the air and storing it or turning it into valuable products.

Researchers at the Missouri University of Science and Technology are doing the latter by creating man-made rocks from CO2. The resulting material also could be used to make cement. Cement production is a carbon-intensive industry and is becoming more so, but innovative carbon capture technologies can help to reverse the trend, according to the International Energy Agency

“We need ways to not only reduce CO2 emission but also to remove CO2 from the air and utilize or permanently store the removed CO2 at a scale large enough to combat climate change,” Hongyan Ma, Missouri S&T associate professor of civil engineering, said in a news release.

Ma’s multidisciplinary research team is forcing CO2 to react with silicate rocks and industrial wastes captured from power plants, steel mills, cement factories, and concrete recycling facilities. The reactions create carbonate materials, which can be formed into rocks or cement.

These formations occur in nature over millions of years, as seen in natural limestone or dolomite, and can store trillions of tons of carbon. But the process is too slow to address the pressing problem of climate change. The research team’s technologies speed up the process of making carbon-storing rocks for an immediate impact.

Ma estimates the innovation could reduce the amount of CO2 in the atmosphere by 2 billion metric tons each year. He’s seeking investments and additional grant funding to scale up the technologies and move them toward commercialization.

Photo by Michael Pierce, Missouri S&T