A comprehensive universal model framework of microalgae growth dynamics for photobioreactor scaling-up design and optimization

Scaling up microalgae cultivation for large-scale utilization is challenging. To solve this problem and to optimize energy conversion by predicting and regulating the microalgae growth process, a universal and integrated numerical model framework for PBR design and optimization was developed. The model integrates computational fluid dynamics, light transfer, and microalgae growth sub-models, and supports aeration and stirring (dynamic mesh) for mixing. In this work, the model was first used to optimize culture conditions such as stir rate and light intensity, and then verified them experimentally. The model estimated the growth curve and growth rate of microalgae with an average error of 4.59% and a maximum error of 7.14%, respectively. The model can capture the growth kinetics of microalgae under large-scale conditions, and provide guidance for large-scale microalgae cultivation. Besides, we obtained that the traditional viewpoint of the dynamic illumination strategy is not exact and some PBR improvements for enhancing mixing and illumination were suggested.