new photobioreactor for continuous microalgal production in hatcheries based on external-loop airlift and swirling flow

• Published in: Biotechnology and bioengineering Vol. 102; no. 1; pp. 132 - 147
• Main Authors: Loubière, Karine, Olivo, Erell, Bougaran, Gael, Pruvost, Jérémy, Robert, René, Legrand, Jack
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 2009; Wiley; Wiley Subscription Services, Inc
• Subjects: airlift; Algae; Aquaculture; Biological and medical sciences; Bioreactors; Biotechnology; Cell Culture Techniques - methods; Chemical and Process Engineering; Cloning; continuous photobioreactor; Engineering Sciences; Eukaryota - growth & development; Fish hatcheries; Fundamental and applied biological sciences. Psychology; hatchery; Isochrysis; Isochrysis affinis galbana; Light; Membrane reactors; Methods. Procedures. Technologies; Mollusca; Mollusks; Studies; swirling flow; Various methods and equipments; ISE, Pacific, French Polynesia, Society Is., Iles du Vent, Tahiti; Continuous process; hatchery; continuous photobioreactor; Bioreactor; Isochrysis affinis galbana; swirling flow; Algae; Photobioreactor; Production; airlift
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.22035

This study deals with the scale of a new photobioreactor for continuous microalgal production in hatcheries. The combination of the state-of-art with the constraints inherent to hatcheries has turned the design into a closed, artificially illuminated and external-loop airlift configuration based on a succession of elementary modules, each one being composed of two transparent vertical interconnected columns. The liquid circulation is ensured pneumatically (air injections) with respect to a swirling motion (tangential inlets). A single module of the whole photobioreactor was built-up to scale its geometry (diameter and length) and to optimize its design (air sparger, tangential inlets). The volumetric productivities were predicted by modeling radiative transfer and growth of Isochrysis affinis galbana (clone Tahiti). The hydrodynamics of the liquid phase was modeled in terms of global flow behavior (circulation and mixing times, Péclet number) and of swirling motion decay along the column (Particle Image Velocimetry). The aeration performances were determined by overall volumetric mass transfer measurements. Continuous cultures of Isochrysis affinis galbana (clone Tahiti) were run in two geometrical configurations, generating either an axial or a swirling flow. Lastly, the definitive options of design are presented as well as a 120-L prototype, currently implemented in a French mollusk hatchery and commercialized. Biotechnol. Bioeng. 2009;102: 132-147.