(674d) Effects of Total Inorganic Carbon On Growth of Chlorella Vulgaris

Microalgae have recently received great attention as a promising alternative bioenergy source because they can produce a substantial amount of triacylglycerols (e.g. 20-50 % dry cell weight) and can be readily converted into biodiesel. Chlorella vulgaris has been selected for this growth kinetic study since it is one of the fastest growing microalgae and contains a reasonable amount of triacylglycerols (e.g. 14-22 % dry cell weight). Dissolved carbon dioxide (CO₂ (aq)) and bicarbonate ion (HCO₃^-) are essential inorganic carbon forms required for autotrophic algal growth, but few studies have been systematically conducted on the impact of inorganic carbon on algal growth. In this study, we will present the impact on growth by controlling dissolved total inorganic carbon under supersaturation and saturation conditions in a batch mode while other operating parameters including the initial pH and nutrients, temperature, and light intensity are kept constant. Based on the mass balances obtained for carbon, nitrogen, and phosphorus, a growth kinetic expression will be determined for batch culture. In addition, the design of plug-flow photobioreactor will be presented by incorporating the growth kinetic expression into the performance equation.