Biological determinants of photobioreactor design. 6th Quarterly report, October 1994--December 1994
A novel photobioreactor (PBR) system using light-emitting diodes (LEDs) as a sole light source was constructed and operated with continuous medium perfusion. Direct internal illumination by 680 nm LEDs could deliver as high as 50 mW/cm{sup 2} of light into the culture medium. Gas transfer by internal sparging had the capacity to transfer 250 mmol O{sub 2}/L culture/h. Nutritional limitations could be overcome by continuous perfusion, supplying the medium components to the culture without increasing osmolarity, while removing potentially inhibitory cellular wastes. When the PBR operated in a continuous perfusion mode with a perfusion rate of 6 reactor volumes a day (6 VVD), it could support ultra high-density algal cultures up to cell concentrations of 4{center_dot}10{sup 9} cells/mL and total cell volume fractions of 9.4% v/v (about 25 g dry weight/L). The oxygen production rate at its peak was 13 to 15 mmol/L culture/h. This performance represents the highest reported cell densities attained in photoautotrophic cultures. Continuous perfusion allowed for long-term stable oxygen production, while oxygen production in batch mode ceased when stationary phase was reached. The results presented suggest that PBR technology can still be significantly improved.
- Research Organization:
- Michigan Univ., Ann Arbor, MI (United States). Dept. of Chemical Engineering
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG22-93PC93212
- OSTI ID:
- 10120869
- Report Number(s):
- DOE/PC/93212-T5; ON: DE95007997; TRN: 95:002192
- Resource Relation:
- Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
Similar Records
Biological determinants of photobioreactor design. Third quarterly report, June 1, 1994--August 31, 1994
Biological determinants of photobioreactor design. Final report, September 1, 1993--August 31, 1995