Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Biological Engineering

Committee Chair(s)

Ronald C. Sims


Ronald C. Sims


Issa A. Hamud


Mac McKee


Darwin L. Sorensen


Charles D. Miller


The demand on alternative energy is rapidly increasing because the reserves of conventional fuel are decreasing and their impacts on the environment are increasing.
Developing renewable energy sources should receive utmost attention. The production of biofuels like methanol, biodiesel, and methane from various kinds of abundant biomass represents a very attractive energy source that can reduce the dependence on conventional fossil fuels energy.

Since algae contains high amounts of nitrogen and low carbon content, this research focused on anaerobic fermentation of algae to produce methane by blending algae with a supplemental carbon source material, sodium acetate. This was done to increase the carbon content of the material fed to the anaerobic process to improve its fermentation and thus increase the amount of methane produced. Laboratory experiments were conducted to determine the favorable proportionality of carbon and nitrogen content. These experiments showed that the best carbon to nitrogen ratio should be 21/1 by weight. A follow-on experiment was conducted for approximately 81 days with the carbon to nitrogen ratio adjusted to 21/1 in the mixture of algae and sodium acetate to be fermented. This experiment used a bioreactor called an up-flow anaerobic sludge blanket reactor with continuous flow. The results from this experiment showed that 80% of the organic matter decomposed and the methane content was approximately 90% of the total biogas produced. It was estimated that 349 mL of methane was produced by each gram of organic matter decomposed.