Published December 14, 2022
By Christine Reed
John Kaszuba, the University of Wyoming’s John and Jane Wold Centennial Chair in Energy and School of Energy Resources professor of geology and geophysics, recently published an article in collaboration with Pacific Northwest National Laboratory (PNNL) that advances carbon dioxide storage research.
The new high-profile, peer-reviewed article in Nature Reviews Chemistry discusses how CO2 converts from a gas to a solid in ultrathin films of water on underground rock surfaces. These solid minerals, known as carbonates, are both stable and common.
The article, led by UW graduate and PNNL Research Scientist Quin Miller, advances understanding of how CO2 behaves when stored in the subsurface. The article is a continuation of research conducted during Miller’s Ph.D. work through Kaszuba’s mentorship.
“Quin has done an excellent job to advance the understanding of how and when these carbonates form, and our maintained contact has yielded multiple opportunities for professional collaboration,” Kaszuba says. “This paper, in particular, is a compilation of the existing modeling, computational and experimental data and provides a concise, holistic review of the research on the topic.”
A recognized expert in hydrothermal and multiphase fluid-rock reactions, Kaszuba was among the first scholars to examine carbon mineralization and has published on the subject for more than two decades. His early publications have been cited nearly 900 times, and he has since published 30 papers examining the geologic sequestration of CO2.
Kaszuba’s expertise has led to a comprehensive understanding of how CO2 interacts in different geologic formations, including limestone formations in the Greater Green River Basin, as well as the sandstone formations that will serve as the target storage reservoirs in the Wyoming CarbonSAFE Project in the Powder River Basin.
“We have learned that CO2 is more readily mineralized -- or converts to minerals -- in the basalts far quicker than a sandstone or a limestone will, but the water in the pores of those sedimentary rocks holds the dissolved CO2,” Kaszuba says. “This is important because we know that, through mineralization, the CO2 no longer migrates and remains permanently in the subsurface, while dissolved CO2 simply sits in the water in the pore space, but it doesn’t go anywhere.”
According to Kaszuba, this critical knowledge plays an important role in ensuring the safety of long-term CO2 storage in different locations around the world and provides a foundation for applied research in the field to progress.
“Understanding CO2, water and rock interactions is vital to mitigating any sort of risk or concern related to geologic carbon storage,” he adds. “The 20-plus years of research indicate not only that we can store carbon dioxide in the subsurface, but we can do it safely and responsibly.”
The partnership with PNNL has led to a second important publication on basalt formations, written by Kaszuba’s current Ph.D. student, Ellen Polites, from York, Pa. Polites recently published an article, “Exotic Carbonate Mineralization Recovered from a Deep Basalt Carbon Storage Demonstration,” in Environmental Science & Technology.
The article examines the reactive subsurface environment of the Wallula Basalt Carbon Storage Pilot Project that demonstrated that CO2 injected into greater than 800 meters deep in the Columbia River Basalt Group flow top reservoirs mineralizes on month-year timescales.
The paper is the result of both Polites’ work on the basalt formation through her internship with PNNL and her studies in the Kaszuba research group and will serve as the first part of her dissertation detailing water and rock interactions. Research examining the Mowry Formation as a caprock for the whole system is another part of her doctoral research.
“I am excited that there has been such an uptick of research on a topic that I helped to pilot,” Kaszuba says. “I am even more pleased that my current and former students have lifted that mantle and are now the experts. Quin’s work on the basalts has elevated him as a leader in the field, whereas students in my current research group are looking to fill any remaining gaps in the sedimentary rock formations.”
Kaszuba continues to build upon his expertise and also investigate opportunities to take advantage of the carbon reactions that can be leveraged to achieve both net-zero goals and economic benefits for Wyoming.
“As we continue to study these mineral-fluid interactions, we also are finding new ways in which we can take advantage of those chemical reactions to produce commodities of value,” he adds. “Investigating these types of challenge is where we excel -- combining geology, geochemistry and environmental stewardship to find solutions for a clean energy future.”