Doctor of Philosophy, The Ohio State University, 2019, Environmental Science

Reducing carbon dioxide (CO2) emissions is one of the most pressing issues facing the electricity system. Towards this end, prior work investigated generating electricity with geologically stored CO2 by using it to extract heat from sedimentary basins geothermal resources. This dissertation expands on this idea by developing and valuing approaches for CO2-based energy storage. In the first chapter, we investigate the value that three bulk energy storage (BES) approaches have for reducing system-wide CO2 emissions and water requirements: CO2-Bulk Energy Storage (CO2-BES), which is a CO2-based energy storage approach that uses a concentric-ring, pressure based (CRP-BES) design, Pumped Hydro Energy Storage (PHES), and Compressed Air Energy Storage (CAES). Our results suggest that BES could decrease system-wide CO2 emissions by increasing the utilization of wind, but it can also alter the dispatch order of regional electricity systems in other ways (e.g., increase in the utilization of natural gas power capacity and of coal power capacity, decrease in the utilization of nuclear power capacity). While some changes provide negative value (e.g., decrease in nuclear increased CO2 emission), the system-wide values can be greater than operating cost of BES. In the second and third chapters, we investigate two mechanisms for using CO2 for energy storage: storage of (1) pressure and (2) heat. For pressure storage, we investigated the efficacy of the CO2-BES system using the CRP-BES design over cycles of varying durations. We found that CO2-BES could time-shift up to a couple weeks of electricity, but the system cannot frequently dispatch electricity for longer durations than was stored. Also, the cycle duration does not substantially affect the power storage capacity and power output capacity if the total time spent charging, discharging, or idling is equal over a multi-year period. For thermal energy storage, we investigated the efficacy of using pre-heated CO2 and pre-h (open full item for complete abstract)

Committee: Jeffrey Bielicki (Advisor); Ramteen Sioshansi (Committee Member); Gil Bohrer (Committee Member); Brent Sohngen (Committee Member) Subjects: Alternative Energy; Energy; Engineering; Environmental Economics; Environmental Science

Doctor of Philosophy, University of Akron, 2018, Polymer Science

Fossil energy from coal, gas, and oil-based fuel stocks remains a vital cornerstone of the global energy infrastructure while contributing over half of annual CO2 emissions. Rising global CO2 concentrations and aberrant trends in climate have sparked recent scrutiny of the energy industry sustainability. Carbon capture, utilization, and storage (CCUS) at the site of power plants has been proposed as a strategy for mitigating atmospheric CO2. This dissertation covers simulated and experimental models designed to address key problems in both the fundamental science and applied engineering of amine-functionalized silica sorbents for carbon capture from few molecule DFT (density functional theory) calculation to kilogram-scale technology validation. DFT was used to emulate small molecule and polymeric amines with good agreement in four successive series of models. (i) The concept of CO2 adsorption strength on secondary amines was investigated which revealed lone amine sites produce weakly adsorbed species while dense amine pairs yield strongly adsorbed species. (ii) Mixed amine types are common in blended or polymeric amine systems and convolute data interpretation. The hydrogen bonding ability of ammonium carbamate pairs demonstrated significant dependence on amine type and local hydrogen bond partners. (iii) Fixation of amines onto substrates is a ubiquitous strategy for preparing CO2 sorbents. The effect of geometric constraint imposed by immobilization was investigated for simulated propylamine pairs. Binding energy was linearly dependent on the alignment of ammonium carbamate. FTIR features were categorized into four groups. (iv) Selective formation of carbamic acid was studied by modeling reactants, intermediates, transition states (TS), and products of the amine-CO2 reaction on simulated diamine substrates. It was shown that significant reduction in TS activation energy occurred by Grotthus-like proton hopping. Coal-fire power plant CO2 capture was experime (open full item for complete abstract)

Committee: Steven Chuang (Advisor); Mesfin Tsige (Committee Chair); Tianbo Liu (Committee Member); Stephen Cheng (Committee Member); David Perry (Committee Member) Subjects: Chemical Engineering; Chemistry; Materials Science; Physical Chemistry; Polymers