Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Rogers, E. Rudy

Committee Member

Minerick, R. Adrienne

Committee Member

Hill, J. Priscilla

Committee Member

French, W. Todd

Date of Degree

5-2-2009

Document Type

Graduate Thesis - Open Access

Major

Chemical Engineering

Degree Name

Master of Science

College

James Worth Bagley College of Engineering

Department

Dave C. Swalm School of Chemical Engineering

Abstract

Bacillus subtilis capable of producing surfactin was cultured to evaluate effects of microbial cell mass on natural gas hydrate formation, dissociation, and stability characteristics. The direct molecular influences of microbial cell wall polymers inhibited gas hydrate formation significantly, decreased hydrate formation rates, and increased dissociation rates. Upon the introduction of bentonite, significant synergy was observed in the system in the form of a catalytic effect. Microbes cultured from seafloor seawater-saturated sediments collected from Mississippi Canyon 118 (MC-118) produced similar effects and generalized the observed trends. MC-118 cultures also produced biosurfactant in several culture media, which was shown to catalyze natural gas hydrate formation in porous media. Microorganisms inhabit gas hydrate macrostructures and consume hydrocarbons and other substrates from within. Sulfate reduction and anaerobic hydrocarbon oxidation occurred within gas hydrate during incubations with MC-118 indigenous consortia. A mathematical model was developed to explore the diffusion-reaction implications in massive seafloor gas hydrates.

URI

https://hdl.handle.net/11668/15153

Comments

gas hydrate||microorganisms||mathematical modeling

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