Fig. 6.

Cyclic photosynthetic hydrogen-producing bioreactor. The microalgal culture circulates between two illuminated main chambers. At 25 °C, the culture grows in an aerobic bottle (1); at 37 °C, the culture produces hydrogen in silicon tubing which passes through a sealed anaerobic collection chamber (3). While cycling from one chamber to the other, the culture is acclimated to the required temperature (2)