Numerical simulation of vortex flow field generated in a novel nested-bottled photobioreactor to improve Arthrospira...

In this study, computational fluid dynamics were employed to examined clockwise and anticlockwise vortexes in the rising and down coming sections of novel nested-bottle photobioreactor. The radial velocity was increased by four times which significantly reduced dead zones compared to traditional PBR. The (NB-PBR) comprised of integrated bottles connected by curved tubes (d = 4 cm) that generated dominant vortices as the microalgae solution flows through each section (h = 10 cm). The (NB-PBR) was independent of the inner and outer sections which increased the mixing time and mass-transfer coefficient by 13.33 % and 42.9 %, respectively. Furthermore, the results indicated that the (NB-PBR) showed higher photosynthesis efficiency preventing self-shading and photo-inhibition, resulting in an increase in biomass yield and carbon dioxide fixation by 35 % and 35.9 %, respectively.