A University of Delaware researcher is working with the Department of Energy to better understand chemical reactions between liquids and solids.
The research could help efforts to capture carbon dioxide underground before it reaches the atmosphere and contributes to climate change.
Neil Sturchio, a geological sciences professor, is working with Argonne National Lab and University of Illinois at Chicago to test these reactions on a molecular level. At a radiation facility, The researchers are using an X-ray beam on a mineral called mica to explore how solids and liquids interact at the molecular level.
“We reflect the X-ray beam off the surface of a mineral while it’s in contact with a liquid solution. Then we measure the intensity of the reflected X-ray beam,” Sturchio said.
The X-ray beam allows trillions of photons per second to hit the mineral. By carefully measuring the reflected photons, researchers can construct a picture of where the solids and liquids meet at the atomic scale, Sturchio said.
Knowing that could help address climate change. Sturchio said one possible idea for capturing carbon dioxide that’s generated from fossil fuels is to liquify it and pump it into the ground into rock formations filled with salty water.
“The idea is that if you pump the CO2 down there, it will react with the briny solution and with the rocks and minerals that are down in that aquifer and eventually the carbon dioxide will either become dissolved in the brine or it will precipitate as carbonate minerals and it will no longer be able to enter the atmosphere,” Sturchio said.
The data could also provide insight into nuclear power and waste. Sturchio said when scientists use nuclear power to generate energy for electricity, it generates nuclear waste as a result. When the energy is used up, highly radioactive nuclear fuel is leftover.
Sturchio said that radioactive nuclear waste is supposed to go to a geological repository like a deep underground mine where the spent fuel would be buried inside of canisters. It would be isolated from the environment until it cools off.
“But, if there’s a scenario where the nuclear waste leaks out of the repository and gets into the groundwater and some of it dissolves, the radioactive isotopes start migrating through the groundwater and they can eventually reach earth’s surface where some unsuspecting people might drink them or might eat food that is contaminated by nuclear waste.”
In this case, Sturchio said there’s been a lot of research focused on how if nuclear waste elements leached out of a repository, how they would interact with rocks in the ground.
“It’s a very serious hazard,” he said.
So far, the team is testing chemical reactions between liquids and solids at room temperature and pressure. Sturchio said he’d like to experiment at higher temps and pressures to simulate conditions deep underground.
Journal reference: Sang Soo Lee, Paul Fenter, Kathryn L. Nagy & Neil C. Sturchio. Real-time Observation of Cation Exchange Kinetics and Dynamics at the Muscovite-Water Interface. Nature, 2017; 8: DOI: 10.1038/ncomms15826.