Types of Microalgae Cultivation Photobioreactors and Production Process of Microalgal Biodiesel as Alternative Fuel

The main purpose of this review is to evaluate the design of several photobioreactor (PBR) systems with the microalgae cultures and the quality of the microalgae species related to the production of lipid for biodiesel. In general, microalgae cultivation is divided into two systems: open pond system (unstirred, circular, raceway) and closed system (flat-panel, horizontal tube, helical tube, vertical tube, stirred tank, big bag), made by transparent and waterproof materials, and able to provide an ideal cultivation environment for photosynthetic microalgae. There are some issues to be considered in microalgae cultivation systems such as modelling by simulation, data collecting, mixing, illumination, gas exchange, availability of the nutritions and the cost of the system. Most common microalgae for PBRs and their lipid percentages as follows: Chlorella ellipsoidea %84, Schizochytrium sp . %77, Botryococcus braunii %74, Nitzschia sp. %51 Chlorella protothecoides %51 and Neochloris oleoabundans %54. The high lipid content of the microalgae is not only sufficient parameter, but also they should be resistant to harsh conditions, capable of rapid growth and easy to culture. Ultimately, this article focuses on applications in PBRs and gives an outlook for this field, aiming at microalgae cultivation and biodiesel production from microalgal lipids.