Design Considerations for Photo-Bioreactors: A Review

Microalgae cultivation for energy production has gained a great interest in the past few decades in view of the increase in Green House Gas (GHG) emission and the global climate changes. The main challenge of producing microalgal based biofuels is to produce sufficient amount of biomass at minimal costs and at high efficiencies. The reason why engineers have examined and developed new technologies for the production of microalgal biomass. In this work, different types of photo-bioreactor systems for microalgae cultivation exploited in literature are classified and evaluated. Moreover, the main design considerations of a photo-bioreactor (surface-to-volume ratio, optimal diameter and length for tubular photobioreactors, mixing process, orientation and inclination, light and CO 2 supply) to provide a controlled environment in order to achieve optimal growth and product formation of microalgae are listed and discussed thoughtfully.