An Automated Helical Photobioreactor Incorporating Cyanobacteria for Continuous Hydrogen Production

Abstract

A laboratory-scale, helical tubular photobioreactor, made of polyvinyl chloride tubing, was constructed to study photobiological H2 production by cyanobacteria catalyzed by cellular nitrogenase. The photobioreactor was connected to a computer, with specially written software and hardware, for automated control of the biochemical and environmental processes regulating H2 evolution. A basic photobioreactor unit with a photostage volume of 4.35 L and containing Anabaena azollae grown in 98% air + 2% CO2 gas mixture produced H2 at a rate of 13 mL H2·h−1·L−1 culture suspension when the gas phase was changed to Ar. The H2 production was sustained for 6 h. No H2 evolution was observed in the presence of photosynthetic O2.