Characteristic Comparison of Two Photobioreactors in Microalgal Culture

This paper is intended to comprehensively evaluate the properties of 30L flat plate photobioreactor and 42L columnar air-lift internal loop photobioreactor. The main parameters of two photobioreactors are determined, and chaetoceros gracilis are cultured for comparing their characteristics. Results indicate that the flat plate photobioreactor has higher circulation velocity and lower light attenuation degree and could be more beneficial to absorbing light efficiently, and the cell numbers and growth rate of chaetoceros gracilis can reach to 6.98×108/mL and 1.42/d respectively under favorite culture conditions. Also, it can be used in microalgal high-density culture in large scale. Compared with flat plate photobioreactor, cell numbers and growth rate are only 1.52×108/mL and 0.935/d respectively in columnar air-lift internal loop photobioreactor, however, the operational factors can be controlled stably, and it could cultivate microalgae under axenic condition. Therefore, this kind of photobioreactor has advantages in research of microalgal growth dynamics and condition optimization. The findings suggest that different types of photobioreactor should be employed to culture microalga based on different application purpose.