Modeling and simulation of the growth of microalgae in photobioreactors

Development of new-source of energy which is renewable and carbon neutral is necessary for mankind's environmental and economic sustainability. Among the new sources of energy being explored, biodiesel derived from oil crops and from microalgae is the most potential and promising source. However, the production period of oil plants is also one of the primary concerns. More so, meeting the increasing demand of energy from oil plants would require the world to use virtually all of its arable land which also competes with the increasing demand of food supply. Microalgae which is the most potential source of biodiesel overcomes such drawbacks. Microalgae use primary sunlight and CO2 to produce oil. Oil content in microalgae can exceed 80% by weight of dry mass and they can double their biomass within 24 h. Although a number of photobioreactors (PBRs) have been proposed for large scale production of microalgae, only a few can be practically used because of the following factors: most designed PBRs limit the entry of light throughout the PBR, the mixing technique to attain a homogenous mixture throughout the PBR of is not yet achieved, the injection mechanism of CO2 and other nutrients needed for optimum growth of microalgae is not yet perfected. Computational Fluid Dynamics (CFD) which has a wide application in the field of engineering will be used to solve the problems presented. CFD is a promising technique which can simulate the growth and production of microalgae in the PBR. More so, an optimum design of a PBR to maximize its production efficiency can be achieved using the pre-processing and the main module approach of CFD.