Development of a novel multi-column airlift photobioreactor with easy scalability by means of computational fluid dynamics simulations and experiments

•A scalable 300 L vertical multi-column airlift reactor was designed.•Hydrodynamics including irradiation and shear stress were studied by CFD.•Optimal operation manner and structure of the novel reactor were determined.•Superiority of the optimized PBR was validated by cultivation experiments.

Aiming to culture algae with high efficiency, a novel vertical multi-column airlift photobioreactor (VMAPBR) has been developed. It was constructed with a series of vertically arranged parallel columns with easy scalability. The hydrodynamic, irradiation and shear stress characteristics of the photobioreactor were studied by computational fluid dynamics (CFD). Accordingly, the optimal aeration manner and aeration rate were determined. When the novel airlift PBR was alternately aerated with aeration rate of 0.2 vvm, the biomass concentration of Chlorella pyrenoidosa under outdoor condition reached 1.30 g L−1 within the prototype PBR and was further increased to 1.56 g L−1 within the optimized PBR. The result of cultivation experiment had good agreement with that of CFD prediction.