Date of Award
MS in Engineering - Bioengineering
Biomedical and General Engineering
Investigation of Microalgae Growth Kinetics using Coal-Fired Flue Gas as a Carbon Source
Bryan Daniel Brooker
Energy related carbon dioxide (CO2) emissions make up the majority of the United States’ greenhouse gas emissions. Emissions must be alleviated to reduce the effects of global climate change. Microalgae cultivation sequesters CO2 while producing biomass. Algal biomass can provide a renewable feedstock for biofuel and electricity production, and ingredients for pharmaceuticals, nutraceuticals, pigments and cosmetics. Utilizing microalgae to mitigate CO2 emissions encourages energy independence by providing a feedstock for biofuels and offers other potentially profitable avenues for the uses of biomass. This study focused on investigating the algal growth kinetics of microalgae cultivated with artificial coal-fired flue gas.
Two algal strains, Chlorella vulgaris and Tetraselmis sp. were cultivated in lab scale photobioreactors to assess the feasibility of using flue gas as a carbon source for microalgae growth. The microalgae growth kinetics were compared between flue gas and pure CO2 treatments for each algal strain. Both microalgae species were able to grow under flue gas dosing. The differences in growth characteristics for Chlorella were statistically insignificant between the two gas dosing treatments. Tetraselmis yielded identical maximum specific growth rates among the two gas treatments, while the biomass production was greater using CO2. At a 95% confidence interval, the difference in biomass production between the gas treatments ranged from 45 to 225 mg/L. The decrease in biomass production for Tetraselmis was the only sign of growth inhibition from flue gas. Overall, Chlorella vulgaris and Tetraselmis sp. are capable of fixating CO2 from coal-fired flue gas.