Abstract

The accelerating global demand for energy is intensifying energy shortages and challenging climate resilience, driven by rising CO2 emissions. Addressing these challenges requires improving energy efficiency, developing low-carbon technologies, and enabling scalable CO2 removal. This dissertation investigates two interconnected systems to advance these goals. The first examines mineral formation at liquid–liquid interfaces in enhanced energy recovery and water treatment systems, where scaling reduces energy recovery efficiency. The second explores mineralization as a dual strategy for CO2 removal and critical element recovery, with a focus on integrating carbonation and sulfidation pathways. In System 1: interfacial CaSO4 formation in enhanced energy recovery, we investigate CaSO4 nucleation and growth at oil–water interfaces. At unconfined flat oil–water interfaces, we elucidate the CaSO4 preferentially distributed at the oil–water interfaces and demonstrate that the interfacial nucleation pathway differs from nucleation in bulk solution. This new thermodynamic perspective provides strategies to better manage scaling during petroleum extraction, thereby lowering operational costs. We then extend the study to nanoscale confined water in oil emulsions, examining nucleation pathways under confinement. We further reveal how emulsion concentration influences crystallization behavior and how mineral nucleation destabilizes emulsions. In System 2: integrated CO2 removal and critical element recovery, we examine ultramafic rocks as feedstocks for integration of CO2 sequestration and recovery of critical elements, such as nickel (Ni). First, we study Ni dissolution processes from natural ultramafic rocks, low-quality ores, highlighting the role of Fe passivation in inhibiting olivine reactivity and demonstrating that reductant can enhance dissolution rates. Second, after ions are released into solutions from solid phases, we investigate coupled carbonation and sulfidation to selectively precipitate Mg as Mg-carbonate and Ni as nickel sulfide from leachates. Third, to extend the carbonation and sulfidation methods to other silicate feedstocks, we compare the reactivity of ultramafic rocks with different silicate structures to understand structural effects on carbonation and sulfidation. Fourth, to explore the influence of water flow on carbonation, we conduct experiments in natural-analog systems with flowing water and pore structures, using a microfluidic device to reveal how hydrodynamics and water transport regulate the carbonation process. Finally, to make the carbonation economically viable, we explore valorization pathways by applying carbonate coprecipitates into electrode materials, linking CO2 sequestration with value-added applications. This dissertation provides a new mechanistic understanding of mineralization processes in both natural and engineered systems. For subsurface energy recovery, it identifies strategies to control CaSO4 scaling and improve operational efficiency. For climate mitigation, it develops cost-effective pathways for CO2 removal while simultaneously recovering critical elements, and it demonstrates valorization routes that enhance economic viability. Collectively, these contributions advance a sustainable circular economy approach that links efficient energy recovery, CO2 mitigation, and resource recovery.

Committee Chair

Young-Shin Jun

Committee Members

Richard Axelbaum; Srikanth Singamaneni; Xinhua Liang; Zhen (Jason) He

Degree

Doctor of Philosophy (PhD)

Author's Department

Energy, Environmental & Chemical Engineering

Author's School

McKelvey School of Engineering

Document Type

Dissertation

Date of Award

12-19-2025

Language

English (en)

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Available for download on Saturday, December 18, 2027

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