In a proposed carbon-capture method, magnesium oxide crystals on the ground bind to carbon dioxide particles from the surrounding air, activating the formation of magnesium carbonate. Credit: Adam Malin/ORNL, U.S. Dept. of EnergyOak Ridge National Laboratorys research study on magnesium oxide for carbon capture reveals a slowing absorption rate over time due to surface layer formation, presenting obstacles for economic viability and assisting future solution-focused studies.Magnesium oxide is a promising product for catching carbon dioxide straight from the atmosphere and injecting it deep underground to limit the results of climate modification. Andrew Stack, a researcher at ORNL and group member on the project, followed: “If we can do so, this procedure might be able to attain the Carbon Negative Energy Earthshot objective of capturing gigaton levels of carbon dioxide from air for less than $100 per metric lot of carbon dioxide.
In a proposed carbon-capture technique, magnesium oxide crystals on the ground bind to carbon dioxide particles from the surrounding air, setting off the formation of magnesium carbonate. The magnesium carbonate is then heated up to convert it back to magnesium oxide and launch the co2 for positioning underground, or sequestration. Credit: Adam Malin/ORNL, U.S. Dept. of EnergyOak Ridge National Laboratorys research study on magnesium oxide for carbon capture reveals a slowing absorption rate in time due to surface area layer formation, positioning obstacles for economic practicality and directing future solution-focused studies.Magnesium oxide is an appealing material for capturing carbon dioxide straight from the atmosphere and injecting it deep underground to restrict the effects of environment modification. However, making the technique economical will require discovering the speed at which carbon dioxide is soaked up and how environmental conditions impact the chemical reactions involved.Scientists at the Department of Energys Oak Ridge National Laboratory (ORNL) analyzed a set of magnesium oxide crystal samples exposed to the environment for decades, and another for days to months, to assess the response rates. They found that co2 is used up more slowly over longer period since of a responded layer that forms on the surface area of the magnesium oxide crystals.”This reacted layer is a complicated mix of various solids, which restricts the ability of carbon dioxide particles to discover fresh magnesium oxide to respond with. To make this innovation affordable, we are now looking at methods to conquer this armoring result,” said ORNLs Juliane Weber, the projects principal private investigator. Andrew Stack, a scientist at ORNL and staff member on the project, followed: “If we can do so, this process may be able to accomplish the Carbon Negative Energy Earthshot goal of recording gigaton levels of carbon dioxide from air for less than $100 per metric heap of carbon dioxide.”Most of the previous research, focused on understanding how quickly the magnesium oxide and carbon dioxide chemical responses take place, depend on rough computations instead of materials screening. The ORNL research study marks the very first time a multidecade test has actually been performed to figure out the response rate over long time scales. Using transmission electron microscopy at the Center for Nanophase Materials Science, or CNMS, at ORNL, the scientists found that a reacted layer forms. This layer includes a variety of intricate crystalline and amorphous hydrated and carbonate stages.”Additionally, by performing some reactive transportation modeling computer simulations, we identified that as the responded layer develops, it improves and much better at obstructing carbon dioxide from discovering fresh magnesium oxide to react with,” ORNLs scientist Vitaliy Starchenko stated. “Thus, going forward, we are looking at methods to bypass this process to allow carbon dioxide to find fresh surface with which to react.”The computer simulations assist engineers and researchers understand how the reacted layer alters the method and progresses in which compounds move through it in time. Computer system models enable predictions concerning the reactions and motion of materials in natural and engineered systems, such as products sciences and geochemistry.Reference: “Armoring of MgO by a Passivation Layer Impedes Direct Air Capture of CO2” by Juliane Weber, Vitalii Starchenko, Ke Yuan, Lawrence M. Anovitz, Anton V. Ievlev, Raymond R. Unocic, Albina Y. Borisevich, Matthew G. Boebinger and Andrew G. Stack, 22 September 2023, Environmental Science & & Technology.DOI: 10.1021/ acs.est.3 c04690The DOE Office of Science primarily supported the work. ORNLs Laboratory Directed Research and Development program supported time-of-flight, or TOF, secondary ion mass spectrometry, or SIMS, and preliminary transmission electron microscopy, or TEM. Atomic force microscopy-TOF-SIMS and TEM characterizations were performed as part of a user task at the CNMS, a DOE Office of Science user center at ORNL.
