Date of Award
8-2025
Document Type
Thesis
Degree Name
Master of Science in Engineering (MSE)
Department
Biosystems Engineering
Committee Chair/Advisor
Dr. Caye Drapcho
Committee Member
Dr. Nhuan Nghiem
Committee Member
Dr. Liz Melvin
Committee Member
Dr. Terry Walker
Abstract
The hyperthermophilic bacterium Thermotoga neapolitana is established as a versatile organism for fermentative hydrogen (H2) production. Batch experiments were carried out to investigate the cell yield, product yield, and kinetic parameter values for individual media containing five carbohydrates. The highest H2 yield of 15.56±0.31 mmol-H2/g-carbohydrate was reported for glucose medium. H2 yield was measured to be 14.51±0.38, 14.44±1.15, 11.88±0.84, and 11.53±0.73 mmol/g for media containing xylose, cellobiose, arabinose and xylan respectively. Acetic acid yield followed a similar trend, where the obtained values were 0.470±0.01, 0.462±0.04, 0.431±0.01, 0.409±0.03, and 0.406±0.01 g-acid/g-carbohydrate for glucose, cellobiose, xylose, arabinose, and xylan media respectively. For cell yield, significant differences observed between treatments and the values were 0.37±0.22, 0.40±0.29, 0.17±0.19, 0.13±0.06, and 0.12±0.05 g-dry-cells/g-carbohydrate for glucose, xylose, cellobiose, xylan and arabinose media respectively. For glucose medium, the maximum specific growth rate () and the half-saturation constant (Ks) values were determined to be 0.61±0.20 hr-1 and 1.05±0.75 g/L respectively. The values for xylose, cellobiose, xylan and arabinose media were 0.29±0.05, 0.54±0.30, 0.28±0.04, 0.20±0.12 hr-1 respectively. A model was constructed to simulate T. neapolitana reaction kinetics in a high temperature simultaneous saccharification (SSF) reaction for the conversion of sugarcane bagasse into H2. The effects of variation in solids retention time (SRT) and hydraulic retention time (HRT) on conversion, system volume, and product formation demonstrate the utility of the model for bioreactor scale-up and optimization.
Recommended Citation
Jeffries, Frank W. V, "Biological Hydrogen Process Improvements by High Temperature Simultaneous Saccharification and Fermentation" (2025). All Theses. 4592.
https://open.clemson.edu/all_theses/4592