Modeling of microalgal shear‐induced flocculation and sedimentation using a coupled CFD‐population balance approach

作者：Mohammad Golzarijalal, Farzin Zokaee Ashtiani, Bahram Dabir · 发表于：Biotechnology Progress · 年份：2017 · DOI：10.1002/btpr.2580 · 被引用次数：12 · 研究领域：Minerals Flotation and Separation Techniques、Algal biology and biofuel production、Coagulation and Flocculation Studies

In this study, shear‐induced flocculation modeling of Chlorella sp. microalgae was conducted by combination of population balance modeling and CFD. The inhomogeneous Multiple Size Group (MUSIG) and the Euler–Euler two fluid models were coupled via Ansys‐CFX‐15 software package to achieve both fluid and particle dynamics during the flocculation. For the first time, a detailed model was proposed to calculate the collision frequency and breakage rate during the microalgae flocculation by means of the response surface methodology as a tool for optimization. The particle size distribution resulted from the model was in good agreement with that of the jar test experiment. Furthermore, the subsequent sedimentation step was also examined by removing the shear rate in both simulations and experiments. Consequently, variation in the shear rate and its effects on the flocculation behavior, sedimentation rate and recovery efficiency were evaluated. Results indicate that flocculation of Chlorella sp. microalgae under shear rates of 37, 182, and 387 s−1 is a promising method of pre‐concentration which guarantees the cost efficiency of the subsequent harvesting process by recovering more than 90% of the biomass. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:160–174, 2018