Evaluation of scale-up methodologies and computational fluid dynamics simulation for fucoxanthin production in airlift photobioareactor

Researches about commercial-scale production of fucoxanthin are increasing day by day due to the much interest of its broad beneficial health effects. The aim of this study was to investigate the scale-up methodologies in airlift photobioreactor and to simulate fluid flow using computational fluid dynamics (CFD) for fucoxanthin production fromPhaeodactylum tricornutummicroalgae. During the transition process from 1-L cultivation bottle to the 2-L airlift photobioreactor, the constant mixing time, the constant volumetric oxygen transfer coefficient, and the constant volumetric power consumption rate were evaluated as scale-up methodologies under laboratory conditions. Maximum fucoxanthin yield was found as 1.01 +/- 0.07 mg g(-1)using scale-up strategy based on constant volumetric power consumption rate. After that, CFD simulation was performed in order to examine flow characteristics, mixing efficiency, hydrodynamics, and gas holdup for selected operation conditions. It was observed that mixing efficiency was low because the draft tube configuration prevented the circulation of fluid and caused a heterogenic culture medium inside the reactor. It is possible to overcome this bottleneck by developing the effective draft tube.