PNNL

The Science

Increasing global emissions and warming have heightened the urgency of finding sites suitable for the long-term capture and storage of carbon dioxide (CO₂). An approach that combines carbon storage with critical material extraction could make both processes more economically viable and broaden the number of suitable sites. Researchers developed a methodology to determine the potential for carbonation and critical mineral recovery in understudied mafic–ultramafic reservoirs. This method was then applied to a Hawaiian picrite (olivine-rich) basalt as a test case scenario.

The Impact

Effectively mitigating climate change requires finding ways to store CO₂ permanently. Mineralization is the process of converting CO₂ into stable carbonate minerals and represents one promising route to long-term carbon sequestration. Recent research has also shown that during this carbonation reaction, critical minerals can be mobilized. If collected, these minerals present an important new revenue source for carbon storage projects. By developing a methodology to assess the potential of a geological site for combined carbon storage and critical mineral recovery, this research can help identify areas that have been deemed uneconomical for traditional mining but may be suitable for carbon mineralization and critical mineral recovery.

Summary

Locating and developing practical sites for the large-scale capture and storage of CO₂ has become increasingly necessary due to rising global emissions and warming. Mafic–ultramafic rocks present a unique geologic setting as they can trap injected CO₂ in their pore space and mineralize it to carbonate minerals, while simultaneously releasing critical minerals. However, these reservoirs are undercharacterized relative to sedimentary carbon storage settings. Researchers developed a method for determining carbonation and critical mineral recovery potential in mafic–ultramafic reservoirs. They began with a test case—an olivine-rich basalt from the island of Hawai’i. Through various X-ray based analyses, they identified its chemistry, mineralogy, and pore network architecture. They quantified the total storage potential of the basalt as well as its realistic potential for storing CO₂ permanently in the form of carbonate minerals. Based on the identified chemistry and mineralogy, the team estimated maximum and realistic mineralization and critical mineral recovery potential for the system. This storage resource estimate methodology can help accelerate the global commercialization of geologic carbon storage and critical mineral recovery.

Contact

Quin Miller, Pacific Northwest National Laboratory, quin.miller@pnnl.gov

C. Heath Stanfield, Pacific Northwest National Laboratory, charles.stanfield@pnnl.gov

Funding

This work was performed at the Pacific Northwest National Laboratory (PNNL) with support from Darin Damiani from the Department of Energy and the DOE Office of Fossil Energy and Carbon Management through its Carbon Storage program. We also acknowledge support from Dr. Douglas Wicks (DOE HQ) and the DOE Advanced Research Projects-Energy MINER program under contract no. 22/CJ000/09/02. C.H.S. was supported by the DOE, Office of Science (SC), Office of Workforce Development for Teachers and Students, under the Science Undergraduate Laboratory Internships Program at PNNL. C.H.S., Q.R.S.M., R.C., and H.T.S. were partially supported by the Carbon Utilization and Storage Partnership project. A portion of this research was performed at the Environmental Molecular Sciences Laboratory, a DOE SC user facility sponsored by the Biological and Environmental Research program. PNNL is operated by Battelle for DOE under contract no. DE-AC05-76RLO1830.