Thesis (Ph. D.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains xi, 160 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed Apr. 22, 2010). Includes abstract. Includes bibliographical references (leaves 85-90).

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains ix, 66 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 66).

Carbon Capture and Storage is a nascent technology developed with the intention of collecting carbon dioxide emissions from the flue gasses of point source producers, such as power stations or cement works. The carbon dioxide is then stored in underground geological reservoirs so that it does not reach the atmosphere, reducing the rate at which greenhouse gasses accumulate and influence climate change. However, as with all nascent technologies, the benefits of these developments and concepts must be weighed against the risks of serious and long-term environmental impact should an accidental release occur. The aim of this thesis is to study the potential for environmental damage caused by a release of carbon dioxide into the marine environment from a sub-seabed carbon dioxide reservoir generated through carbon capture and storage development. The quantification of the rate of change caused by such an accidental release of carbon dioxide will be studied, as will the rate at which natural conditions are re-established upon cessation of the release.

Limited information is available on carbon(C)sequestered in frigid Appalachian forest soils. However,the cool moist forests of the high elevations probably hold more C than any other mineral soils in Virginia. The objectives of the study were to determine the amount and variability of soil C across aspect and slope classes in a frigid temperature regime area of Tazewell County, VA. Soils were sampled to characterize two aspect classes, N(340-90) and S (160-270), and three slope classes, 7-15%, 15-35%, 35-55%. Organic (L,F,H) and mineral layers and horizons (upper 5cm, A, B) were sampled at each site. Whole soil (including organic and mineral horizons) C contents on N aspects (135 Mg/ ha) were greater than on south aspects (107 Mg/ha). Average whole soil C across all sites was 112 Mg ha-1. The A horizons on N aspects (13cm) were deeper than those of the S aspects (8 cm), while average leaf litter weights were greater on the S aspects (25 Mg/ ha) versus the N (17 Mg/ ha). B horizon C was greater than 1.5 % and made up more than half of the total soil C. Carbon increased with slope on N aspects, but did not increase with slope on S aspects, because estimated solar insolation potential decreases with increasing slope on N aspects and has no trend on S-facing slopes. Total C appears to be greatest on steep N-facing slopes because cooler and moister conditions promote better mixing of organic material into the mineral soil. / Master of Science

The mitigation of greenhouse gas emissions and enhanced recovery of coalbed methane are benefits to sequestering carbon dioxide in coal seams. This is possible because of the affinity of coal to preferentially adsorb carbon dioxide over methane. Coalbed methane is the most significant natural gas reserve in central Appalachia and currently is economically produced in many fields in the Basin. This thesis documents research that assesses the capacity of coal seams in the Central Appalachian Basin to store carbon dioxide and verifies the assessment through a field validation test. This research allowed for the first detailed assessment of the capacity for coal seams in the Central Appalachian Basin to store carbon dioxide and enhance coalbed methane recovery. This assessment indicates that more than 1.3 billion tons of carbon dioxide can be sequestered, while increasing coalbed methane reserves by as much as 2.5 trillion cubic feet. As many of the coalbed methane fields are approaching maturity, carbon sequestration and enhanced coalbed methane recovery has the potential to add significant recoverable reserves and extend the life of these fields. As part of this research, one thousand tons of carbon dioxide was successfully injected into a coalbed methane well in Russell County, Virginia as the first carbon dioxide injection test in the Appalachian coalfields. Research from the field validation test identified important injection parameters and vital monitoring technologies that will be applicable to commercial-scale deployment. Results from the injection test and subsequently returning the well to production, confirm that fractured coal seams have the potential to sequester carbon dioxide and increase methane production. It was demonstrated through the use of perfluorocarbon tracers that there is a connection through the coal matrix between the injection well and surrounding producing gas wells. This connection is a cause for concern because it is a path for the carbon dioxide to migrate to the producing wells. The thesis concludes by presenting options for mitigating carbon dioxide breakthrough in commercial-scale injection projects. / Ph. D.

Chironomus riparius are the least sensitive aquatic species in the U.S. EPA (2000) species sensitivity distribution (SSD) for cadmium (Cd). LC50 values over 25,000 times the Criterion Maximum Concentration suggest that chironomids have an extraordinary capacity to excrete or sequester cadmium as a means of increasing their overall tolerance to toxic metals. Using atomic absorption spectroscopy, we have shown saturable uptake of cadmium by whole chironomids and isolated guts. The transport of Cd from the gut lumen to the hemolymph exposes other tissues such as the nervous system and muscles to Cd. To quantify the movement of Cd2+ from the main point of entry, the digestive tract, we have identified regional differences of Cd transport along the gut using a Cd2+ -selective microelectrode in conjunction with the Scanning Ion Selective Electrode Technique (SIET). Cd2+ fluxes were determined in high mucosal or serosal Ca2+ to analyze the contribution of Ca2+ transporters to Cd2+ uptake. The major tissues responsible for elimination of Cd2+ from the hemolymph are the posterior midgut and the ileum. In addition, experiments using an isolated Malpighian tubule preparation (the Ramsay assay) have shown that the Malpighian tubules both sequester and secrete Cd2+. The tubules can secrete the entire hemolymph burden of Cd^2+ in~ 18 hours. / Thesis / Master of Science (MSc)

Double-difference seismic tomography is performed on a carbon sequestration operation in the Aneth Oil Field in southeast Utah as part of a Department of Energy initiative on monitoring, verification, and accounting of sequestered CO2. A total of 1,211 seismic events were recorded from a borehole array of 22 geophones. Aneth Unit data were divided into four time periods for time-lapse analysis. A low velocity zone spanning the lateral extents of the observable region, likely representing a CO2 plume, is detected when considering voxels containing the highest ray path coverage. A series of synthetic tomography tests simulating different CO2 plume sizes and locations was performed to assist in characterizing velocity changes associated with Aneth Unit data. Inferences about the existence of a CO2 plume should be made by comparing actual data to synthetic data resulting from simulations performed under similar conditions. Considering synthetic simulation similarities and a derivative weight sum analysis, a CO2 plume can be imaged within the Desert Creek reservoir, but the resolution of the CO2 plume is too low for proper monitoring, verification, and accounting of injected CO2. Recommendations, for improving CO2 plume resolution through double difference seismic tomography, are made to increase the ray path distribution throughout the Aneth Unit by varying geophone locations. / Master of Science

Mineralization has the potential to capture CO₂. In nature, mineralization is the chemical weathering of alkaline-earth minerals in which stable carbonate minerals are formed, which leads to the removal of CO₂ from the atmosphere. The adsorptive carbonation reaction of olivine ((Mg,Fe)₂SiO₄)), consisting mainly of pure magnesium silicate (Mg₂SiO₄), a main constituent of the Earth’s crust, was carried out to estimate its potential application to the separation of CO₂ in the presence of water vapor in combustion plumes. Based on the thermodynamics for a basis of the reaction mechanism, the olivine carbonation reaction is thermodynamically favorable. Water vapor was found to play an important role in improving the carbonation rate, and experimental results revealed that carbon dioxide carbon dioxide can bind into olivine minerals to form highly stable surface carbonates. The reaction activity of olivine and pure Mg₂SiO₄ in the presence/absence of water vapor was carried out by varying the temperature, reactant concentrations, and space time. Based on changes in CO₂ concentration with time, the reaction kinetic model of pure Mg₂SiO₄carbonation was developed. The reaction order was found to be approximately 1 for CO₂. The activation energy derived for the Arrhenius equation of Mg₂SiO₄-based carbonation is 76.2 ± 4.8 kJ/mol based on the changes in the reaction rates with temperature in the range of 150-200°C. To investigate the molecular reaction mechanism of CO₂ adsorption on the metal oxide surface, forming carbonates, we performed the quantum mechanical calculation of CO₂ adsorption on a CaO (100) surface. It shows that CO₂ molecules strongly react with the CaO surface due to its high reactivity and high basicity. Consequently, this study will basically lay the groundwork for the chemical mechanism of mineral carbonation of olivine with carbon dioxide in the presence of water vapor and as provide relevant information for the practical application of CO₂ sequestration by stable adsorption on mineral silicates.

Leakage of stored bulk phase CO₂ is one risk for sequestration in deep saline aquifers. As the less dense CO₂ migrates upward within a storage formation or in layers above the formation, the security of its storage depends upon the trapping mechanisms that counteract the migration. The trapping mechanism motivating this research is local capillary trapping (LCT), which occurs during buoyancy-driven migration of bulk phase CO₂ within a saline aquifer with spatially heterogeneous petrophysical properties. When a CO₂ plume rising by buoyancy encounters a region where capillary entry pressure is locally larger than average, CO₂ accumulates beneath the region. One benefit of LCT, applied specifically to CO₂ sequestration and storage, is that saturation of stored CO₂ phase is larger than the saturation for other permanent trapping mechanisms. Another potential benefit is security: CO₂ that occupies local capillary traps remains there, even if the overlying formation that provides primary containment were to be compromised and allow leakage. Most work on LCT has involved numerical simulation (Saadatpoor 2010, Ganesh 2012); the research work presented here is a step toward understanding local capillary trapping at the bench scale. An apparatus and set of fluids are described which allow examining the extent of local capillary trapping, i.e. buoyant nonwetting phase immobilization beneath small-scale capillary barriers, which can be expected in typical heterogeneous storage formation. The bench scale environment analogous to CO₂ and brine in a saline aquifer is created in a quasi-two dimensional experimental apparatus with dimension of 63 cm by 63 cm by 5 cm, which allows for observation of plume migration with physically representative properties but at experimentally convenient ambient conditions. A surrogate fluid pair is developed to mimic the density, viscosity and interfacial tension relationship found at pressure and temperature typical of storage aquifers. Porous media heterogeneity, pressure boundary conditions, migration modes of uprising nonwetting phase, and presence of fracture/breach in the capillary barrier are studied in series of experiments for their influences on LCT. A variety of heterogeneous porous media made of a range of sizes of loosely packed silica beads are used to validate and test the persistence of local capillary trapping mechanism. By adjusting the boundary conditions (fluid levels in reservoirs attached to top and to bottom ports of the apparatus), the capillary pressure gradient across the domain was manipulated. Experiments were conducted with and without the presence of fracture/potential leakage pathway in the capillary seal. The trapped buoyant phase remained secure beneath the local capillary barriers, as long as the effective capillary pressure exerted by the trapped phase (proportional to column height of the phase) is smaller than the capillary entry pressure of the barrier. The local capillary trapping mechanism remained persistent even under forced imbibition, in which a significantly higher hydraulic potential gradient, and therefore a larger gradient in capillary pressure, was applied to the system. The column height of buoyant fluid that remained beneath the local capillary barrier was smaller by a factor corresponding to the increase in capillary pressure gradient. Mimicking a breach of the caprock by opening valves at the top of the apparatus allowed buoyant mobile phase held beneath the valves to escape, but buoyant phase held in local traps at saturations above residual, and therefore potentially mobile, was undisturbed. This work provides systematic validation of a novel concept, namely the long-term security of CO₂ that fills local (small-scale) capillary traps in heterogeneous storage formations. Results from this work reveal the first ever unequivocal experimental evidence on persistence of local capillary trapping mechanism. Attempts to quantify the nonwetting phase saturation and extent of LCT persistence serve as the initial steps to potentially reduce the risks associated with long-term storage security. / text