Biological determinants of photobioreactor design. Final report, September 1, 1993--August 31, 1995

Microalgae is being considered for the capture and sequestration of CO{sub 2} from power-plant flue-gases. High productivity of microalgae is necessary to make this process cost effective compared to the conventional methods used for reducing CO{sub 2} levels in the atmosphere. This obviates the need for large-scale cultivation technologies and proper photobioreactor technology. The physical factors that influence the performance of a photoautotrophic microalgal culture are the quality and composition of light, inlet carbon dioxide concentration, nutrients, and secondary metabolites at high cell densities. In developing photobioreactor technology, balancing of biological processes to the physical rate process becomes important. The effect of various light compositions on the culture kinetics was studied. To determine the optimal composition, six wavelengths 470, 555, 560, 570, 580 and 605 nm, each supplemented with 680 nm of red light, were used to cultivate cultures. Based on the results obtained, it is concluded that a monochromatic red light of 680 nm is sufficient to obtain maximum capacity