Carbon Mineralization
A potential mitigation option for rising carbon dioxide concentrations in the atmosphere
Carbon dioxide (CO2) can react with silicate rocks that are rich in magnesium, calcium, and iron to precipitate carbonate minerals. This process is typically referred to as carbon mineralization, which represents a potential mitigation option for rising CO2 concentrations in the atmosphere. The U.S. has pledged to reduce net greenhouse gas pollution to 50-52 percent of 2005 levels, which will involve employing a host of emission reduction strategies; the U.S. Geological Survey is researching carbon mineralization as a mitigation option in order to understand how it can contribute to meeting this pledge.
Introduction
In 2019, the U.S. Geological Survey (USGS) released a carbon dioxide mineralization feasibility report (Blondes and others, 2019). This report was an important first step toward our current work of conducting a national assessment of CO2 storage resources accessible via carbon mineralization. The focus of the work is on mafic (e.g., basalt) and ultramafic (e.g., peridotite and serpentinite) formations that have high concentrations of magnesium, calcium, and iron - these types of rocks are abundant throughout the U.S. The initial steps of the assessment involve refining maps of surface and subsurface CO2 mineralization targets and compiling geochemical and mineralogic data, as well as collecting new samples for analysis in areas where few data exist. All of these data populate a governing equation for CO2 mineralization potential that considers the volume, mineralogy, geochemistry, surface area of reaction, and extent of natural carbonation (which would reduce mineralization potential) of the rocks. The overall aims are to provide an accurate assessment of available lithologic feedstock for CO2 mineralization across the conterminous U.S., and to address the significant geologic variability seen in natural rocks even over small spatial scales.
Unlike CO2 storage in subsurface reservoirs, where CO2 is stored as dissolved and supercritical fluid phases, CO2 mineralization stores carbon in solid phase carbonate minerals that have the potential to remain stable over geologic time periods (thousands to millions of years). In addition to the assessment work, the USGS is also performing research on the conditions and mechanisms for carbon mineralization, including the extent and rates of carbonate precipitation and CO2 uptake. The research is relevant to carbon mineralization applications both in situ, where CO2 injected into the subsurface will mineralize while interacting with the mafic and ultramafic host rocks, and ex situ, where geologic feedstock is mined and introduced to settings (surface or marine) conducive to enhanced rock weathering, which facilitates the removal of CO2 directly from the atmosphere.
References
Blondes, M.S., Merrill, M.D., Anderson, S.T., and DeVera, C.A., 2019, Carbon dioxide mineralization feasibility in the United States: U.S. Geological Survey Scientific Investigations Report 2018–5079, 29 p., https://doi.org/10.3133/sir20185079.
Below are other science projects associated with this project task.
Carbon and Energy Storage, Emissions and Economics (CESEE)
Below are data products associated with this project task.
Geologic formations and mine locations for potential CO2 mineralization
Below are publications associated with this project task.
Carbon dioxide mineralization feasibility in the United States
Below are news items associated with this project task.
Carbon dioxide (CO2) can react with silicate rocks that are rich in magnesium, calcium, and iron to precipitate carbonate minerals. This process is typically referred to as carbon mineralization, which represents a potential mitigation option for rising CO2 concentrations in the atmosphere. The U.S. has pledged to reduce net greenhouse gas pollution to 50-52 percent of 2005 levels, which will involve employing a host of emission reduction strategies; the U.S. Geological Survey is researching carbon mineralization as a mitigation option in order to understand how it can contribute to meeting this pledge.
Introduction
In 2019, the U.S. Geological Survey (USGS) released a carbon dioxide mineralization feasibility report (Blondes and others, 2019). This report was an important first step toward our current work of conducting a national assessment of CO2 storage resources accessible via carbon mineralization. The focus of the work is on mafic (e.g., basalt) and ultramafic (e.g., peridotite and serpentinite) formations that have high concentrations of magnesium, calcium, and iron - these types of rocks are abundant throughout the U.S. The initial steps of the assessment involve refining maps of surface and subsurface CO2 mineralization targets and compiling geochemical and mineralogic data, as well as collecting new samples for analysis in areas where few data exist. All of these data populate a governing equation for CO2 mineralization potential that considers the volume, mineralogy, geochemistry, surface area of reaction, and extent of natural carbonation (which would reduce mineralization potential) of the rocks. The overall aims are to provide an accurate assessment of available lithologic feedstock for CO2 mineralization across the conterminous U.S., and to address the significant geologic variability seen in natural rocks even over small spatial scales.
Unlike CO2 storage in subsurface reservoirs, where CO2 is stored as dissolved and supercritical fluid phases, CO2 mineralization stores carbon in solid phase carbonate minerals that have the potential to remain stable over geologic time periods (thousands to millions of years). In addition to the assessment work, the USGS is also performing research on the conditions and mechanisms for carbon mineralization, including the extent and rates of carbonate precipitation and CO2 uptake. The research is relevant to carbon mineralization applications both in situ, where CO2 injected into the subsurface will mineralize while interacting with the mafic and ultramafic host rocks, and ex situ, where geologic feedstock is mined and introduced to settings (surface or marine) conducive to enhanced rock weathering, which facilitates the removal of CO2 directly from the atmosphere.
References
Blondes, M.S., Merrill, M.D., Anderson, S.T., and DeVera, C.A., 2019, Carbon dioxide mineralization feasibility in the United States: U.S. Geological Survey Scientific Investigations Report 2018–5079, 29 p., https://doi.org/10.3133/sir20185079.
Below are other science projects associated with this project task.
Carbon and Energy Storage, Emissions and Economics (CESEE)
Below are data products associated with this project task.
Geologic formations and mine locations for potential CO2 mineralization
Below are publications associated with this project task.
Carbon dioxide mineralization feasibility in the United States
Below are news items associated with this project task.