Microalgae growth modeling and control for a vertical flat panel photobioreactor

Abstract

Micro-algae have the potential to produce enough bio-fuels to meet the current US fuel demands. In order to achieve this potential, photo-bioreactors (PBRs) need to be developed that are efficient, scalable, and affordable. Models are an analytical tool that can be used to evaluate various PBRs. In this article, a dynamic model is developed for growing micro-algae in a vertical flat panel photo-bioreactor (PBR) that may be used to measure PBR efficiency for various architectures independent of scale. The growth model is used to estimate the micro-algae growth and byproduct production and consumption as a function of incident light. A feed-forward controller is developed that uses the estimated amount of CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> consumed to determine the amount of additional CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> to add to the system during photosynthesis. An overall controller structure that uses both feed-forward and feedback control is presented for growing micro-algae inside a PBR.