On the physics and chemistry of carbon dioxide capture and storage in terrestrial and marine environments

The production of CO2 from the oxidation of fossil-carbon over the past 200 years has resulted in the accumulation of CO2 in the atmosphere. In the atmosphere, CO2---like other greenhouse gases---slows the rate at which radiation is emitted from the Earth. By increasing the concentration of CO2 in the atmosphere, humanity is altering the Earth's radiation balance in a potentially dangerous way. Mitigating humanity's impact on the Earth's climate system requires transforming the global energy infrastructure to decrease anthropogenic emissions of CO 2. The body of work presented here covers a range of physical and chemical topics important for the mitigation of anthropogenic climate change through the capture and storage of CO2. This dissertation is focused primarily on addressing CO2 emissions from large stationary point-sources through CO2 capture and storage (CCS). A portion of the work, however, is aimed at addressing the long tail of the CO2 point-sources distribution by removing CO2 directly from the atmosphere. The entire CCS supply chain from the thermodynamic limit of the work required to capture CO 2 from power-plants to the long-term chemical and physical evolution of CO2 that has been injected into geologic repositories is evaluated with the use numerical models as well as thermodynamic and energetic calculations. In addition, a method to engineer the carbon cycle as an approach to address the long tail of the CO2-point-source distribution was developed. In all five of the chapters, the study of energetics plays an important role. Chapter 2 applies thermodynamics to derive an analytic relationship for the CCS energy penalty, and several valuable insights are ascertained from that relationship. The central insight of chapter 3---that a geologic formation's ability to dissipate induced pressure is often the limiting resource of CO 2 storage---derives from energetic models of compressive flow in porous media. The primary contribution of chapter 4 is the notion that in a certain thermodynamic phase space, liquid CO2 is denser than seawater, and thus it can be gravitationally trapped in deepsea sediments. Chapter 5 extends chapter 4's analysis of state properties to a larger pressure and temperature range. Finally, chapter 6 describes the energetics of accelerating chemical weathering with electrochemistry.