Comparison of tubular and panel type photobioreactors for biohydrogen production utilizing Chlamydomonas reinhardtii considering mixing time and light intensity

Two different photobioreactor designs; tubular and panel, were investigated for the biohydrogen production utilizing a green microalgae Chlamydomonas reinhardtii strain CC124 following the two stage protocol. Mixing time and light intensity of the systems were adjusted to compare the productivity of both aerobic culture phase and the following anaerobic biohydrogen production phase. The results showed there was an effect on both phases related with the design. During the aerobic phase bigger illumination area serving more energy, tubular photobioreactor reached higher biomass productivity of 31.8 ± 2.1 mg L−1 h−1 which was about 11% higher than the panel photobioreactor. On the other hand biohydrogen productivity in the panel photobioreactor reached a value of 1.3 ± 0.05 mL L−1 h−1 based on the efficient removal of biohydrogen gas. According to the results it would be a good approach to utilize tubular design for aerobic phase and panel for biohydrogen production phase.