Mississippi State University
Rogers, Rudy E.
French, W. Todd
Toghiani, Rebecca K.
Hill, Priscilla J.
Date of Degree
Graduate Thesis - Open Access
Master of Science
James Worth Bagley College of Engineering
Dave C. Swalm School of Chemical Engineering
Sediments collected from various cores in Mississippi Canyon 118 were tested to evaluate the abilities to promote natural gas hydrate formation. Memory effects for hydrate formation of sediments with in-situ seawater were of a major concern. The possible mechanisms of memory effects were combined to give an overall hypothesis on the bioproducts-mineral-microorganism system. Unique permanent memory effects in the sediment were found. Temperatures from 50 to 65°C dissipated all memory effects by disrupting microbial cell wall material. Bacillus subtilis is known to produce several types of biosurfactants, including surfactin. The catalytic effect of purified surfactin from B. subtilis on hydrate formation was studied in the presence of smectite clays. The interlayer spacings of clay minerals measured by X-ray powder diffraction indicated that hydrate formation and surfactin adsorption on the smectite clays have impacts on their structures. Laboratory gas mixture sequestering was also conducted by hydrate formation to study the various factors that may affect the separation of its hydrateorming gases. The effects of agitation, temperature, initial pressure and thermal conductors were explored.
Xiong, Shangmin, "Microbially Induced and Disrupted Memory Phenomena during Gas-Hydrate Occurrences in Seafloor Sediments" (2009). Theses and Dissertations. 3082.