Theses and Dissertations at Montana State University (MSU)
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Item Carbon dioxide sequestration underground laser based detection system(Montana State University - Bozeman, College of Engineering, 2009) Barr, Jamie Lynn; Chairperson, Graduate Committee: Kevin S. Repasky; John L. Carlsten (co-chair)Carbon dioxide (CO 2) is a known greenhouse gas. Due to the burning of fossil fuels by industrial and power plants the atmospheric concentration of CO 2 has been rising over the past 50 years. Carbon capture and sequestration provides a method to prevent CO 2 from being emitted into the atmosphere. Successful carbon sequestration will require the development of many pieces of technology including development of monitoring tools and techniques. An underground laser based monitoring system was built and tested at Montana State University (MSU) to measure sub-surface CO 2 concentrations at a sequestration site. The instrument uses differential absorption spectroscopy by temperature tuning a distributed feedback diode laser over several CO 2 absorption features located at 2.004 microns. The instrument utilizes photonic bandgap fibers for sub-surface spectroscopy CO 2 concentration measurements. The instrument was tested at a controlled release facility located on the MSU campus. The field and CO 2 release are managed by the Zero Emissions Research and Technology group at MSU. Three CO 2 injection tests were done over the coarse of two summers to simulate a fault or fracture line at a sequestration site. Results from all three tests are presented showing that the underground differential absorption instrument could be used to monitor sequestration sites.Item Establishment of ureolytic biofilms and their influence on the permeability of pulse-flow porous media column systems(Montana State University - Bozeman, College of Engineering, 2009) Wheeler, Laura Allison; Chairperson, Graduate Committee: Robin GerlachAs the population of the world has increased, energy consumption and greenhouse gas emissions have increased as well. One possible way to reduce the amount of greenhouse gases emitted into the atmosphere is through the geologic sequestration of carbon dioxide. During geologic sequestration, supercritical carbon dioxide is injected into different types of underground formations. Inherent cracks in these formations may lead to the upward leakage of CO 2, and a controllable engineered strategy is needed to reduce this potential leakage. Currently, biomineralization has been used in many different environmental applications but not for the sequestration of carbon dioxide. The goal of this research is to establish biofilm communities of ureolytic bacteria that promote CaCO 3 precipitation in a pulse-flow porous media column system with the intent of reducing the porosity and permeability of the porous media. Pulse-flow column systems were inoculated with different species of ureolytic bacteria: S. pasteurii, B. sphaericus #21776, or B. sphaericus #21787. The bacteria were allowed to grow in the column for five days before a calcium-containing medium was introduced. Flow rate, pH, ammonium concentration, calcium concentration, culturable bacteria, and protein concentration were monitored over the course of the entire experiments. It was shown that all ureolytic species were capable of growing, utilizing urea, and creating an environment that facilitated calcium carbonate precipitation in 1mm diameter glass bead packed columns at room temperature and atmospheric pressure. To better understand the effect of pore space on biomineralization columns packed with 0.1 mm diameter glass beads were constructed and inoculated with S. pasteurii. Within days of calcium introduction, the permeability of the columns was reduced to the point where no more fluid would drain from the column. These results indicate that the ureolytic bacteria are capable of surviving, facilitating calcium carbonate precipitation, and reducing the permeability of the pulse-flow porous media column system. While further study is needed, the precipitation of calcium carbonate through ureolysis may offer a controllable engineered strategy to reduce the permeability of underground formations used for geologic sequestration.Item Design and experimental testing of a high pressure, high temperature flow-through rock core reactor using supercritical carbon dioxide(Montana State University - Bozeman, College of Letters & Science, 2009) Hansen, Logan Carl; Chairperson, Graduate Committee: Mark L. SkidmoreAnthropogenic CO 2 emission is of concern due to its likely contribution to global climate change. Geologic storage of CO 2 in deep brine-bearing aquifers is currently viewed as an alternative to its release to the atmosphere. The effects of injecting CO 2 into these aquifers are poorly understood. An experimental apparatus was developed to reproduce subsurface conditions relevant to geologic sequestration to simulate CO 2 injection and assess CO 2-brine-rock interactions. Technology available for this type of experimental apparatus was advanced by enhancing monitoring capabilities to include in situ pH, EC, pressure, and temperature measurement and continuous logging of these variables. This thesis describes the experimental apparatus and its novel capabilities, demonstrates its accuracy and precision, and presents and discusses a suite of CO 2-brine and CO 2-brine-rock interaction studies relevant to geologic sequestration. Experiments were conducted by flowing brine and/or supercritical CO 2 through the apparatus, with and without rock cores in line. Rock samples were limestones/dolostones from the Madison Formation in the western Black Hills, South Dakota, which was selected based on its applicability as a primary large-scale geological CO 2 storage target. Outcrop blocks were machined to produce cores with minimal evidence of weathering to best simulate subsurface Madison Formation rock. Brines were prepared in the laboratory of a similar composition to reported literature values for in situ Madison formation fluids. Results from the experimental system show good agreement with bench pH and EC measurements when utilizing standardized fluids. Experimental data indicate that adding CO 2 to brine under all tested conditions significantly reduces brine pH, an important control on subsurface geochemistry. This effect is partially buffered by flowing the fluids through Madison rock cores, due to dissolution of carbonate minerals, predominantly dolomite. The experiments indicate that samples of the Madison Formation with in situ brines can be partially dissolved via exposure to supercritical CO 2. Similar processes would likely occur in the subsurface Madison Formation in response to addition of supercritical CO 2. The novel experimental system provided new data that could be utilized in refining geochemical models; however, further improvements can be made to the system to improve its capabilities in this regard.